Matched Content

Monday, July 16, 2012

Front Brake Bleeding By One Mechanic Only

Procedure with photos and video described here is the work of my innovation and it is easy to apply and designed to be done by only 1 (one) mechanic. Tools needed are combination spanner, hose, and container for used brake fluid. At first glance this brake bleeding procedure is similar to the one that already exist. But by lifting the hose higher than nipple and using grease to prevent air enter the system, this procedure can be done by one person only. No need assistance (helper) to open and close nipple many times. With this procedure, brake air bleeding for one wheel can be done in just 15 minutes if no problems. Jack and remove the wheel can take longer time. On some high ground clearance vehicles such as jeep, this procedure can be performed without removing the wheel. Likewise, if you have car lift, brake air bleeding can be done without removing wheels. Because of easy, one with no experience can do it. You can do it in your garage at home.

See a video about three colorful origami boats are sailing together without: fuel, engine, battery, electric motor, and without wind blow. Boats are powered by chemical reaction to provide hydraulic energy.

Photo below shows a hose filled with new red brake fluid after brake bleeding. Used brake fluid is collected in a plastic bottle of mineral water.

In this article, brake bleeding is done for the front brake. To bleed air from the rear brake can be read in the article: Brake Bleeding Practical Procedure By Only One Mechanic.

There is also a simple procedure that uses a pump to push brake fluid in reservoir to go out from nipple. Also there is a procedure that uses a vacuum pump to suck brake fluid from nipple. Although easy, but both procedures require expensive equipment.

Video at the bottom of this post shows the clear brake fluid with air bubbles and red colored brake fluid that come out from brake nipple and go into the transparent hose. A new red brake fluid will replace the old clear brake fluid.

If you just done any repair on piston or cylinder on the wheel or the brake master cylinder (brake pedal cylinder), for example: replacement of rubber seals, it is necessary to bleed air from brake hydraulic system. Air trapped in the hydraulic system will cause no brake pressure. Brake pedal feel light and can be pressed to bottom, and feels like stepping on a balloon or rubber foam. This occurs because the physical properties of air that can be compressed (compressible) and shrink the volume. While the brake fluid can not be compressed (incompressible) or volume always constant even when under pressure.

The usual procedure is requiring two people. One person in charge of pumping the brake pedal until pressure build up, then hold the pedal in a depressed position. Another person is at the wheel to loosen nipple so the air can go out of the hydraulic brake system, and then immediately close nipple again. Brake pedal is then released and pumped again, and so on until the pressure is building up and normal, and pedal does not feel like stepping on a balloon anymore. This usual procedure is written on many websites.

In the video at the end of this article, the bleeding is performed to replace the old brake fluid with new brake fluid. Usually brake fluid is drained every 2 years, please refer to your vehicle service manual. Replacement of brake fluid needs to be done because of moisture or water entering the hydraulic system, and some other material such as: dirt, rubber seal debris, rust, air.

This procedure can also be used to bleed air after a major overhaul on the brake hydraulic system, such as replacement rubber seals in wheel cylinder or in the master cylinder. And can be applied to almost any vehicle using the hydraulic system for brake, including motorcycles.

Brake bleeding should be started from the wheel farthest from the master cylinder. In order for the air and the old brake fluid can get out in the large volume quickly. For cars with the driver position on the right such as Indonesia, Britain, Australia, Japan, Singapore, Malaysia, Hongkong, India, New Zealand, etc. the farthest wheel is the left rear wheel. On some cars, the position of the brake master cylinder is not right near the foot of the driver, on the right side for Indonesia. There are some European cars have master cylinder positioned on the passenger side. Maybe because those cars were originally designed with the driver's position on the left, but later modified to have the driver's position on the right to expand market share.

The first thing that needs to be done before bleeding the brake: open the brake fluid reservoir cap, check brake fluid level, top up to maximum is necessary. The photo below shows brake fluid reservoir pointed by red arrow. Smaller reservoir is for the clutch.

Clean outside reservoir with water, the reservoir is watertight and can be sprayed with water. Open the reservoir cap, the cap on some vehicles have two parts. In the photo below shows the tank cap is opened and still another cap on the inside.

Open the inside cap and attach to the outer cap. The inside cap prevents brake fluid to spill out but still allow air to enter or ventilation. Below photo shows the inside cap is attached to the outside cap. Note the clear Prestone brake fluid inside reservoir. Clear brake fluid will be replaced with a new red coloured brake fluid. Shown also in the photo the brake fluid is around the maximum level. 

Jack and remove the farthest front wheel from the master cylinder, the left front wheel for Indonesia. Make sure the jack is securely positioned. Put the removed wheel under the car and add a block of wood to help jack. As the photos below.

Check for any trace of brake fluid, which indicates a leak and usually happen in piston caliper, nipple, and brake line connection. 

Clean the left front brake and wheel well with water for easy and clean job. Shown in the photo below the front brake of disc type. On some vehicles the front brake is drum type, especially on the old car, bus and pickup truck.

The air bleeding valve is designated by red arrow in the picture above. Located on the inner side of the caliper, its rubber dust cap was removed to show the nipple.

Loosen the air bleeding valve with combination spanner. The front brake of this vehicle is using combination spanner of size 10 mm, use the one that suit your vehicle nipple. Avoid using an open end spanner to loosen and tighten the nipple, because open end spanner only holds two corners of nipple bolt head and can cause damage to nipple bolt head. In the photo below we can see how to loosen the nipple with ring part of combination spanner, the ring spanner holds to all corners of the bolt head nipple and prevent to damage bolt head.

No need to remove nipple, only loosen nipple to about 30 to 60 degrees of rotation. Usually there will be a drop of brake fluid if nipple is loosened to about 30 to 60 degrees of rotation. Tighten slightly to stop brake fluid drip as it needs to wait for the preparation and installation of hose and used fluid container.

Connect a transparent hose diameter 3/16 inch or 5 mm to nipple, as shown below. If the hose too small, it can be widened a little bit by heat in order to fit it to nipple. If the hose too big, then use a smaller rubber hose. As far as I know the smallest diameter of transparent hose is 3/16 inches. There are rubber hoses with smaller diameter, and rubber hose is far more flexible then plastic hose. But the rubber hose is not transparent so we cannot see and check if any air bubbles inside the hose. So if the nipple is too small, connect a rubber hose to nipple, and then connect that rubber hose to a transparent plastic hose. This way we can clearly see and check fluid inside the transparent plastic hose.

At a distance of about 50 cm from the end of the hose on nipple, tie a yarn. This yarn attached to the vehicle body with duct tape (adhesive tape) to make a loop The higher hose loop peak, the easier for air to come out of hydraulic system as air in brake fluid try to go up to higher place. The yarn does not block the view when we look at top of the hose where air bubbles are gathered. The other end of the hose is inserted into a container. Make sure the hose is not leaking. Leaking hose will allow air to enter the hydraulic system. A leaky hose can also spray brake fluid and damage car paint. Immediately flush with clean water if the paint sprayed with brake fluid.

In the picture above shows a hose is connected to nipple, hose goes up as it is hung by yarn and duct tape on the car body. The other end of the hose is inserted into a container of mineral water plastic bottle, make sure this hose end reach the bottom of container. As container is filled by used brake fluid, fluid will prevent air to get into transparent hose via container. This will ensure only air from hydraulic system gathered at top hose, this way it will be easier to check if there is still air in hydraulic system. Although air may enter hose via container, it can't reach nipple as air can't go down passing through brake fluid by itself. We can see air bubbles from hydraulic system will be gathered at top of the hose, nothing air from container, then air is pushed by pedal pressure down into container.

That rised hose will help to remove air bubbles from brake hydraulic system. Air, steam and other gases have physical properties that lighter specific gravity then liquids. Air, steam, and other gases in the hose will tend to go up to higher place when enter the hose together with brake fluid. So the air, steam and gases will 'go up by themselves' to get out of the brake hydraulic system.

Actual length of the hose is not necessarily the same length as the photo above. Since I will use that hose for other purposes, then I do not cut the hose.

To prevent outside air to enter the brake hydraulic brake system through some small holes (pores) around nipple, then apply grease around nipple and at the end of the hose that is attached to the nipple. See the photo below, green grease is pointed by green arrow. Seen also clear brake fluid had started out with some air bubbles, because nipple has been already loosened again about 30 to 60 degrees shortly before being photographed.

Clear brake fluid will be drained and replaced with red brake fluid. If there are air bubbles in the hydraulic system, the brake fluid in the hose will appear foamy or bubbly. Air bubbles will also be seen moving up as they try to get to a higher place in the hose. Ensure enough fluid in brake reservoir, top up with new brake fluid. The photo below shows Prestone red brake fluid is added. The red brake fluid is over maximum level. But because it will be drained, then the brake fluid level will be lowered by itself.

Get into the cabin and sit on the driver's seat. Make sure the parking brake is released, so that all brake wheel cylinders will react when you step on the brake pedal, and release the trapped air and dirt in the wheel cylinder. Press or pump the brake pedal 5 times, the pedal stroke is long as brake fluid and air go out of loosened nipple. No need to turn on the engine, as foot pressure is enough to pump the pedal. No need to open and close nipple many times.

If the brake fluid has not come out, loosen nipple again to about 30 degrees. Too loose nipple will cause too much brake fluid draining and emptying the reservoir, also causes the air easily enter from the gap around nipple thread.

After 5 times pumping the pedal, check brake fluid in reservoir tank, top up if it has reached a minimum level. Check nipple, hose and used brake fluid container on the wheel brake. Make sure there is no leak in the hose, especially on the connection between the hose to nipple. Fix hose connection and add grease if there are drops of brake fluid.

If everything is no problem, then move on and pump the brake pedal as much as 10-15 times. Do not do it in a hurry. Too many pumping will cause brake fluid reservoir empty and the master cylinder will suck air. Any air inside master cylinder will cause longer time to bleed the system.

For a sedan, usually 50-100 times pumping brake pedal is enough for each wheel to drain the old brake fluid and replace with new fluid. For air bleeding may need a little more pumping, especialy after major repair to master cylinder. Because air inside master cylinder must travel into all pipes and enter into wheel cylinders before it can get out of the brake hydraulic system.

The photo below shows the brake fluid after brake pedal pumped few times. Visible in the transparent hose, clear brake fluid with air bubbles go out first. Brake fluid and air can not re-enter the nipple and come into the wheel cylinder as there is a valve mechanism in the master cylinder that makes the master cylinder works like piston pump. 

Then the brake fluid is changed to red. Different color brake fluid is used to to distinguish the old brake fluid from new brake fluid.

When brake fluid has been replaced with new one, shut nipple off with an open end spanner. Do not too tight as it can damage nipple bolt head.

Remove the hose and retighten nipple with ring part of combination spanner, do not too tight because it gets seized and difficult to be loosen in the future. Brake fluid will seal any small holes (pores) to prevent seepage, after sometime nipple will be more tightened like glued. Photo below shows nipple is tightened with a ring spanner, which is the ring part of spanner is used to tighten the nipple.

Put the dust rubber cap on nipple, clean and wipe all parts and area moistened and dripped by brake fluid. Cleaned and dried area will help to spot any fluid leaks. Reinstall wheel, and lower the jack. Do not forget to tighten wheel nuts criss-cross to ensure wheel is really centrist.

The following video shows brake fluid in the hose. At first clear Prestone brake fluid and many bubbles are going out, followed by Prestone red-colored brake fluid. At the end of the video shows nipple is closed by open end spanner. If you can not open this video, please open it on YouTube: Front Brake Bleeding By Only One Mechanic.

Proceed to the second farthest front wheel from brake master cylinder position, it is the right front wheel for cars in Indonesia. Run test your vehicle and brake suddenly to ensure brakes performance. Pedal will feel higher if the air and the old brake fluid are drained away, and do not feel like stepping on soft foam or baloon.

Used brake fluid should not be recycled, because dirt and water can change the nature of brake fluid, although the visual look is still clean. Because brake fluid also functions to clean the hydraulic system, the brake fluid is made to have same chemical properties as soap. It can dissolve the dirt and water, so it can not be filtered. Old brake fluid can be used as component cleaner, particularly components made of plastic and rubber that are not oil resistant.

Do not dispose carelessly as brake fluid can contaminate the environment, if swallowed in large quantities can be harmful to health.

Friday, July 13, 2012

Buang Angin Rem Depan Oleh Satu Orang Mekanik

Prosedur dengan foto dan video yang dijelaskan di sini adalah karya inovasi saya yang mudah digunakan dan didesain untuk dikerjakan oleh hanya 1 (satu) orang mekanik. Alat yang digunakan adalah kunci ring pas (combination spanner), selang, dan penampung minyak rem bekas. Secara sekilas mirip dengan prosedur buang angin rem (brake bleeding) yang sudah ada. Tapi dengan mengangkat selang lebih tinggi dari nipel dan menggunakan gemuk (grease) sebagai pencegah udara masuk, prosedur ini dapat dikerjakan hanya oleh satu orang. Tidak perlu bantuan (helper) untuk membuka dan menutup nipel berkali-kali. Dengan prosedur ini satu roda dapat dibuang angin remya hanya dalam 15 menit jika tanpa masalah, mendongkrak dan melepas roda dapat memakan waktu lebih lama. Pada beberapa kendaraan yang tinggi seperti jip, prosedur ini dapat dilakukan tanpa melepas roda. Demikian juga jika anda memiliki lift untuk mengangkat mobil, angin rem dapat dibuang tanpa melepas roda. Karena mudah, seorang tanpa pengalaman dapat mengerjakannya. Anda dapat mengerjakannya di garasi di rumah anda.

Foto di bawah ini memperlihatkan selang yang terisi minyak rem baru berwarna merah setelah pembuangan angin dilakukan. Minyak rem bekas tertampung di wadah plastik bekas botol air mineral.

Pada artikel ini dibahas pembuangan angin rem di roda depan. Untuk membuang angin rem di roda belakang dapat dibaca di artikel: Cara Praktis Buang Angin Rem Oleh Satu Mekanik

Ada prosedur yang juga mudah yaitu menggunakan pompa untuk menekan minyak rem di reservoir dan keluar dari nipel. Juga ada prosedur yang menggunakan pompa vacuum untuk mengisap minyak rem dari nipel. Walau mudah, tapi kedua prosedur tersebut membutuhkan alat yang mahal.

Gambar video di bagian bawah posting ini memperlihatkan minyak rem berwarna bening dan gelembung yang keluar dari nipel rem dan memasuki selang transparan. Selanjutnya minyak rem yang baru yang berwarna merah memasuki selang menggantikan minyak rem lama yang bening.

Jika baru saja dilakukan perbaikan pada piston atau silinder rem di bagian roda ataupun master cylinder (silinder pedal rem), misalnya penggantian karet seal, maka perlu dilakukan pembuangan angin dari sistem hidrolik rem. Udara atau angin yang terperangkap di dalam sistem hidrolik akan menyebabkan rem tidak pakem. Pedal rem terasa dalam sampai kandas saat diinjak, dan terasa seperti menginjak balon atau menginjak karet busa. Hal ini terjadi karena sifat fisika udara yang dapat ditekan atau dimampatkan (compressible) hingga volumenya mengecil, sedangkan minyak rem tidak dapat dimampatkan (incompressible) atau volumenya selalu tetap walau mendapat tekanan.

Karena sifat cairan seperti minyak rem, air, oli, dan lain-lain yang tidak bisa dimampatkan, maka dimanfaatkan untuk sistem hidrolik dengan tekanan sangat tinggi. Baca juga hidrostatik test bertekanan tinggi mencapai 1500 psi atau sekitar 50 kali tekanan ban, dengan memanfaatkan silinder kopling jip CJ7.

Adapun prosedur yang biasa digunakan, membutuhkan dua orang. Satu orang bertugas memompa pedal rem hingga terasa ada tekanan dan langkahnya jadi agak pendek atau lebih tinggi, lalu pedal ditahan dalam posisi tertekan. Satu orang lagi bertugas mengendurkan nipel rem di roda agar angin dapat keluar dari sistem hidrolik rem, kemudian segera ditutup kembali. Pedal rem dilepas dan dipompa lagi, begitu seterusnya sampai tekanan benar-benar naik dan pedal tidak terasa seperti menginjak balon lagi. Prosedur biasa ini banyak ditulis di situs internet.

Pada video pembuangan angin yang dilakukan dan dijelaskan di sini adalah saat menguras dan mengganti minyak rem lama dengan minyak rem baru. Biasanya minyak rem dikuras setiap 2 tahun sekali, harap merefer ke service manual kendaraan anda. Penggantian minyak rem perlu dilakukan karena adanya embun atau air yang masuk ke dalam sistem hidrolik rem, kotoran, sisa karet seal, karat, udara, sehingga perlu dikuras.

Prosedur ini dapat juga digunakan untuk membuang angin setelah perbaikan besar pada sistem hidrolik rem, misal penggantian karet piston di roda atau karet piston pada master cylinder. Dan dapat diterapkan pada hampir semua kendaraan yang menggunakan sistem hidrolik pada remnya, termasuk sepeda motor.

Membuang angin sebaiknya dimulai dari roda paling jauh dari master cylinder. Agar angin dan minyak rem lama dapat segera keluar dalam jumlah atau volume banyak. Untuk mobil dengan posisi pengendara di sebelah kanan seperti Indonesia, Inggris, Australia, Jepang, Singapura, Malaysia, Hongkong, India, New Zealand, dll. maka roda terjauh adalah roda belakang kiri. Untuk roda depan maka roda terjauh adalah roda depan kiri. Pada beberapa kendaraan, posisi master cylinder rem tidak tepat di dekat kaki pengemudi, yaitu di sebelah kanan untuk Indonesia. Ada mobil Eropa yang posisi master cylindernya di sebelah kiri atau di sebelah penumpang. Mungkin karena mobil tersebut awalnya dirancang dengan posisi pengemudi di sebelah kiri, tapi kemudian dimodifikasi menjadi posisi pengemudi di sebelah kanan untuk memperluas pangsa pasar.

Hal pertama yang perlu dilakukan sebelum rem dibuang anginnya adalah: buka tutup reservoir minyak rem atau tanki rem, periksa tinggi permukaan minyak rem, jika kurang maka tambah sampai maximal. Pada foto dibawah tampak tangki minyak rem adalah yang ditunjuk oleh panah merah. Tangki yang lebih kecil adalah reservoir minyak kopling.

Bersihkan tanki reservoir dengan air, tangki ini kedap air dan bisa disemprot air. Buka tutup reservoir, pada beberapa kendaraan tutupnya ada dua bagian. Pada foto di bawah memperlihatkan tangki yang terbuka dan masih ada tutup lain di bagian dalamnya.

Buka tutup yang di bagian dalam lalu pasangkan ke dalam tutup luar. Tutup di bagian dalam ini berfungsi mencegah minyak rem melimpah keluar reservoir tapi tetap melewatkan udara masuk atau ventilasi. Tampak di foto bawah tutup dalam yang terpasang pada tutup luar. Terlihat juga minyak rem Prestone yang berwarna bening. Minyak rem bening tersebut akan diganti dengan minyak rem berwarna merah. Tampak pada foto minyak rem masih pada sekitar level maximum.

Dongkrak dan buka roda depan yang paling jauh dari posisi pengendara, yaitu roda depan kiri untuk Indonesia. Pastikan posisi dongkrak yang aman. Masukkan roda yang terlepas ke kolong mobil dan tambahkan balok kayu untuk membantu dongkrak. Seperti foto di bawah.

Check jika ada jejak lelehan minyak rem yang menandakan adanya kebocoran, yang biasa terjadi pada piston caliper, nipel, dan sambungan saluran minyak rem.

Bersihkan rem dan spakbor roda depan kiri dengan air agar pekerjaan mudah dan bersih. Tampak pada foto di bawah rem depan dari tipe cakram. Pada beberapa kendaraan rem depannya dari tipe tromol, terutama pada kendaraan bus atau pickup dan kendaraan produk lama.

Katup buang angin (air bleeding valve) adalah yang ditunjuk oleh panah merah pada gambar di atas. Terletak di sebelah dalam caliper (klip, penjepit, cengkam), terlihat karet abunya sudah dilepas agar tampak nipelnya (nipple, puting).

Kendurkan dengan kunci ring pas. Pada rem roda depan mobil ini digunakan kunci ring pas (combination spanner) ukuran 10 mm, sesuaikan dengan nipel kendaraan anda. Hindari menggunakan kunci pas saat mengendurkan dan mengencangkan, karena kunci pas hanya memegang 2 sudut dari kepala baut nipel dan dapat menyebabkan kepala baut nipel rusak. Pada foto di bawah terlihat cara mengendurkan nipel dengan bagian kunci ring dari kunci ring pas, agar kunci memegang semua sudut dari kepala baut nipel dan mencegah kepala baut tersebut rusak.

Tidak perlu sampai melepas nipel, cukup dikendurkan sekitar 30 sampai 60 derajat putaran. Biasanya akan ada tetesan minyak rem keluar jika dikendurkan antara 30 sampai 60 derajat putaran. Kencangkan sedikit agar minyak rem tidak terus menetes karena akan menunggu persiapan dan pemasangan selang dan penampung minyak.

Pasang selang transparan diameter 3/16 inchi atau 5 mm pada nipel, sebagaimana gambar di bawah. Jika selang kekecilan bisa diperbesar sedikit dengan dipanasi agar melebar dan nipel bisa masuk. Jika selang kebesaran, maka gunakan selang karet yang lebih kecil. Setahu saya selang transparan tidak ada yang lebih kecil diameternya dari 3/16 inchi. Selang karet ada yang berdiameter lebih kecil, dan selang karet jauh lebih flexibel dari selang plastik. Tapi selang karet tidak transparan sehingga tidak kelihatan jika ada gelembung udara. Maka jika nipelnya terlalu kecil, pasang selang karet pada nipel lalu selang karet tersebut disambung dengan selang plastik transparan agar bisa dilakukan visual check pada minyak rem.

Pada jarak sekitar 50 cm dari ujung selang di nipel, ikatkan benang. Benang ini ditempelkan ke bodi kendaraan dengan lakban (adhesive tape). Semakin tinggi puncak selang maka semakin mudah angin keluar dari sistem hidraulik, karena angin di dalam minyak rem berusaha mencapai tempat lebih tinggi. Penggunaan benang dimaksudkan agar tidak mengganggu jika melihat ke dalam puncak selang di mana busa atau gelembung udara berkumpul. Ujung selang yang lain dimasukkan ke dalam penampung minyak rem. Pastikan tidak ada bagian selang yang bocor. Selang yang bocor dapat memasukkan udara ke dalam sistem hidrolik rem. Selang yang bocor juga dapat menyemprotkan minyak rem yang dapat merusak cat mobil. Segera siram dengan air bersih jika cat terkena minyak rem.

Pada gambar di atas terlihat selang yang terpasang pada nipel, selang naik ke atas karena digantung dengan benang dan lakban pada bodi mobil. Ujung selang lainnya dimasukkan ke dalam kontainer penampung dari botol plastik bekas air mineral. Ujung selang yang ini sebaiknya menyentuh dasar kontainer. Ketika kontainer terisi minyak rem bekas, maka ujung selang akan tertutup dari udara luar. Sehingga hanya angin dari sistem hidrolik yang terkumpul di bagian atas kontainer, dengan cara ini akan mudah dicheck apakah masih ada angin di dalam sistem hidraulik. Walaupun udara dari kontainer dapat masuk ke dalam selang yang terisi minyak rem, tapi tidak bisa masuk ke dalam nipel karena udara tidak bisa turun sendiri melewati minyak rem. Kita dapat melihat angin dari nipel berkumpul di bagian atas selang, tidak ada udara dari kontainer, lalu angin terdorong ke dalam kontainer oleh tekanan pedal.

Selang yang naik ke atas akan membantu mengeluarkan udara dari sistem hidrolik rem. Udara, uap, dan gas lainnya mempunyai sifat fisika berat jenis yang lebih ringan dari cairan. Udara, uap, dan gas-gas di dalam selang akan berusaha naik ke tempat yang lebih tinggi saat selang dimasuki oleh minyak rem. Maka udara, uap dan gas-gas tersebut akan 'berusaha sendiri' untuk keluar dari sistem hidrolik rem.

Sebenarnya panjang selang tidak perlu sepanjang seperti pada foto di atas. Karena saya masih akan memakai selang tersebut untuk keperluan lain, maka selang tidak saya potong.

Untuk mencegah udara luar masuk ke dalam sistem hidrolik rem melalui celah-celah nipel, maka oleskan gemuk (grease) di sekitar nipel dan ujung selang yang terpasang pada nipel. Lihat foto di bawah, gemuk berwarna hijau. Terlihat juga minyak rem berwarna transparan sudah mulai keluar dengan beberapa gelembung udara, karena nipel sudah dikendurkan kembali sekitar 30 sampai 60 derajat sesaat sebelum difoto.

Minyak rem yang berwarna bening akan dikuras dan diganti dengan minyak rem berwarna merah. Jika terdapat gelembung udara pada sistem hidrolik, maka minyak rem di dalam selang akan tampak berbusa atau berbuih. Gelembung udara juga akan tampak bergerak naik karena berusaha mencapai tempat yang lebih tinggi di dalam selang.

Pastikan tinggi minyak rem di dalam tanki reservoir, tambah minyak rem dengan yang baru. Di foto di bawah tampak minyak rem Prestone berwarna merah ditambahkan. Sebenarnya tinggi minyak rem merah sudah melebihi dari tinggi maximal. Tapi karena akan dikuras, maka minyak rem akan berkurang sendiri nantinya.

Masuk ke kabin dan duduk di kursi pengemudi. Pastikan rem parkir tidak bekerja, agar semua silinder rem pada roda dapat bereaksi saat pedal rem diinjak, dan melepaskan udara dan kotoran yang terjebak di dalam silinder roda. Injak atau pompa pedal rem 5 kali, pedal akan terasa dalam karena minyak rem keluar dari nipel yang kendur. Tidak perlu menyalakan engine, karena tekanan kaki sudah cukup untuk memompa pedal. Tidak perlu membuka dan menutup nipel berkali-kali.

Jika minyak rem belum keluar, kendurkan lagi nipel sekitar 30 derajat. Nipel yang terlalu kendur akan menyebabkan minyak rem mengucur terlalu banyak dan cepat mengosongkan tanki, juga menyebabkan udara mudah masuk dari sela-sela ulir nipel.

Setelah 5 kali pedal dipompa, periksa minyak rem dalam tanki reservoir, tambah jika sudah sampai level minimal. Periksa nipel, selang dan penampung minyak rem di roda yang dikuras minyak remnya. Pastikan tidak ada kebocoran pada selang, terutama pada sambungan antara selang dengan nipel. Perbaiki sambungan selang dan tambahkan grease jika ada tetesan minyak rem.

Jika semuanya tidak ada masalah, maka lanjutkan menginjak pedal rem dan pompa sebanyak 10-15 kali. Jangan lakukan tergesa-gesa. Jika terlalu banyak memompa, minyak rem di tanki reservoir bisa habis dan master cylinder akan mengisap udara. Jika master cylinder mengisap udara maka pembuangan angin akan lebih lama dilakukan.

Untuk mobil sedan biasanya memompa atau menginjak pedal rem 50-100 kali untuk setiap roda sudah dapat menguras minyak rem lama dan terganti dengan yang baru. Untuk pembuangan angin bisa agak lebih banyak memompanya, terutama setelah perbaikan besar pada master cylinder. Karena angin yang masuk ke dalam master cylinder harus berjalan ke semua pipa dan menuju silinder di roda-roda sebelum dapat keluar dari sistem hidrolik rem.

Foto di bawah memperlihatkan minyak rem yang dipompa dengan menginjak pedal rem berulang-ulang. Di dalam selang transparan, mula-mula keluar minyak rem berwarna bening bersama gelembung udara. Minyak rem dan udara tidak bisa kembali masuk ke nipel dan ke dalam silinder roda ataupun sistem hidrolik rem karena ada mekanisme katup pada master cylinder yang membuat master cylinder bekerja seperti pompa piston.

Lalu minyak rem berganti menjadi berwarna merah. Warna minyak rem yang berbeda berguna sebagai tanda untuk membedakan minyak rem baru dan minyak rem lama. Minyak rem berwarna merah tampak di foto di atas mengisi selang.

Jika minyak rem sudah berganti dengan yang baru dan tidak ada lagi gelembung udara dari nipel, tutup nipel dengan kunci pas. Jangan tutup terlalu kuat karena kunci pas dapat merusak kepala baut nipel. Kunci pas dapat memegang kepala baut nipel walau selang masih terpasang pada nipel.

Lepaskan selang dan kencangkan nipel dengan kunci ring, jangan terlalu kencang karena akan macet dan sulit membukanya di kemudian hari. Minyak rem akan menutup setiap sela dan lubang kecil (pori-pori) guna mencegah rembesan, dengan berjalannya waktu nipel akan semakin kuat terpasang seperti lengket atau dilem. Foto di bawah memperlihatkan nipel dikencangkan dengan kunci pas ring, yang mana bagian kunci ring yang digunakan untuk mengencangkan nipel.

Pasang kembali karet abu pada nipel, bersihkan dan lap semua komponen yang terkena minyak rem. Dengan bersih dan keringnya area yang terkena minyak rem maka akan mudah terlihat jika ada minyak rem yang menetes. Pasang roda, dan turunkan dongkrak. Jangan lupa untuk mengencangkan baut roda secara silang agar roda benar-benar sentris.

Video berikut memperlihatkan minyak rem di dalam selang. Mula-mula tampak keluar minyak rem Prestone berwarna bening dan banyak gelembung udara, lalu diikuti dengan minyak rem Prestone berwarna merah. Pada akhir video terlihat nipel ditutup dengan kunci pas. Jika anda tidak bisa membuka video ini, harap membuka di YouTube: Buang angin rem depan oleh satu mekanik.

Lanjutkan ke roda depan terjauh kedua dari posisi master cylinder, yaitu roda depan kanan untuk posisi sopir di kanan seperti pada mobil di Indonesia. Uji kendaraan anda dengan menjalankan dan rem mendadak untuk memastikan kinerja rem. Pedal akan terasa lebih tinggi jika udara dan minyak rem lama sudah terkuras habis, dan tidak terasa lunak seperti menginjak busa atau balon.

Minyak rem bekas jangan didaur-ulang, karena kotoran dan air dapat mengubah sifat minyak rem, walau secara visual terlihat masih bersih. Karena minyak rem harus membersihkan sistem hidrolik rem, maka minyak rem dibuat mempunyai sifat kimia seperti sabun, dapat melarutkan kotoran dan air, sehingga tidak dapat disaring. Minyak rem bekas dapat digunakan sebagai pembersih komponen, terutama komponen yang terbuat dari plastik dan karet yang tidak tahan minyak.

Jangan membuang minyak rem sembarangan karena dapat mencemari lingkungan, jika terminum dalam jumlah banyak dapat membahayakan kesehatan.

Saturday, July 7, 2012

Rain Tree Overshadows Various People To Earn A Living

Rain tree (Albizia saman, Samanea Saman) the world's largest oxygen producer, overshadows many people to earn a living, such as: motorcyclist, tire repair shop, shop, cafe, restaurant, minimart. There is an orange and white minibus of Pos Indonesia parks and serves there. Photographed during lunch time, seen the writings of 'POS' at the closed back door of minibus. When busy people get together and lining up around the minibus, if photographed it does not appear that the minibus is a mobile post office.

Someone with blue shirt is repairing motorcycle tire on the right of post office minibust. At dawn many taxi-cab are parked and waiting for passengers to Jakarta from Cinere, Depok, Pondok Cabe, and surrounding areas. Some taxi drivers say that they spend the night under that rain tree as they are late to go home, and hope for the passengers in the morning. When scorcher, a lot of people take shelter under this tree while waiting for public transport.

Under this tree, It used to be a terminal for bus Patas P-18A Pondok Labu - Grogol. Before 6:00 am, many people were waiting bus under the tree. The first bus left at 6:00 and always full. There were no permanent buildings under this tree. There are only simple food stalls for students and employees of the Universitas Pembangunan Nasional, banks, hospital, private office, and Armed Forces from the surrounding neighborhood.

As far as I know there has never been a broken branch, although the tree grows to the side and sheltering a large area. Hopefully it will not happen.

May be the tree needs to be trimmed, but not to be cut. It's good to clean the area around the tree and laid out to avoid to become a slum area and continue as a shelter for various people, continue to produce oxygen, and helping turn the economy. Development does not have to sacrifice nature.

Pohon Trembesi (Albizia Saman, Samanea Saman) produsen oksigen terbesar dunia menaungi berbagai kalangan mencari nafkah, seperti: ojek, bengkel ban, warung, warnet, restoran, minimart. Ada minibus putih oranye Pos Indonesia diparkir dan melayani di situ. Difoto saat jam istirahat, terlihat tulisan ‘POS’ dan ‘bayardi’ di pintu belakang minibus yang tertutup. Saat sibuk orang-orang berkumpul dan antri di sekitarnya, jika difoto tidak kelihatan bahwa minibus tersebut adalah kantor pos berjalan.

Seseorang berbaju biru memperbaiki ban sepeda motor di kanan mobil pos. Saat subuh taxi-taxi mangkal menunggu penumpang tujuan Jakarta dari Cinere, Depok, Pondok Cabe, dan sekitarnya. Beberapa sopir taxi mengaku bermalam di bawah pohon ini karena telat pulang, dan berharap mendapat penumpang esok paginya. Saat panas terik banyak orang berteduh di bawah pohon ini sambil menunggu kendaraan umum.

Dulu di bawah pohon ini dijadikan terminal bus Patas P-18A Pondok Labu - Grogol. Sebelum jam 6:00 pagi, sudah ramai orang menunggu bus di bawah pohon. Bus pertama berangkat jam 6:00 selalu penuh sesak sampai berdiri. Dulu tidak ada bangunan permanen di bawah pohon ini. Hanya ada warung-warung sederhana untuk mahasiswa dan karyawan dari Universitas Pembangunan Nasional, bank, rumah sakit, swasta, dan Hankam/TNI di sekitarnya.

Setahu saya belum pernah ada dahan yang patah, walau tumbuhnya melebar ke samping menaungi wilayah yang luas. Semoga tidak akan terjadi.

Mungkin perlu dipangkas, tapi semoga tidak perlu ditebang. Ada baiknya area sekitar pohon dibersihkan dan ditata agar tidak kumuh dan tetap menjadi tempat bernaung berbagai kalangan, terus memproduksi oksigen, dan membantu memutar ekonomi. Pembangunan tidak harus korbankan alam.

Friday, July 6, 2012

Guide Choosing And Buying Digital Camera

Photo cameras are still popular although high-tech video cameras are already available at affordable prices. Strange phenomenon if we consider the logic. But when viewed from the side of art, this phenomenon is still acceptable. Art of photography can not be replaced by video, although video is very similar to the original event as it has moving images and sound.

I have learned photography as my hobby since I was in high school. Some of my photos are published in this blog with label "intermezzo".

How do we choose the right camera? First of all consider your needs. Do you need moving images and sound or video image, or simply capture the moment with a photo camera.

I prefer to use a video camera, especially when capturing events or moments that take place continuously, such as weddings, birthdays, sporting events, and others. Those moments take place quickly and continuously, and we can not capture one by one. So by using a video camera, we can record every moment continuously. And then replay to see which moments are the best. By seeking out the best moments of recorded event, then we can get best frames to become photos. Some digital photo camera can also record video with excellent quality and length up to several hours.

Currently various types of digital cameras available on the market at very affordable prices. Even the digital camera is bundled with other devices such as mobile phones and tablet computers.

Types of Photo Camera
There are three types of photo camera, that are: pocket, prosumer and DSLR (Digital Single Lens Reflex). If you intend to carry the camera with ease wherever you go, then pocket type camera is suitable for you. Pocket-sized camera is small and easily stored in the pocket. It is lightweight and does not feel heavy in your pocket. The price also will not make you feel heavy to your pocket. That is why so-called pocket camera.

If you want to create a sophisticated picture with high technique, DSLR camera is suitable for you. You can replace the camera lens with different type of lenses to suit every moment to be captured. The resulting image has a high resolution level reached 36.3 megapixels, so it can be enlarged to poster size, even can be printed for wallpaper size. DSLR camera can have different features and settings that can be tailored to your needs, such as setting: shutter speed, aperture diaphragm , ISO, and others. Various accessories for digital SLR cameras available for every shooting needs, to enable to produce the best image.

The term Single Lens Reflex is to explain that the viewfinder is looking through the same lens with the lens used to take picture or so-called Single Lens. This allows the image is produced with the exact same scene viewed when aiming the camera. Viewfinder of SLR camera use a mirror to reflect light from lens to view through that lens. The mirror will quickly folded up when the photo is taken, this to allow the light from the object comes into the lens and to the film, the mirror movement is like a reflex movement. This is why it is popularly called Single Lens Reflex. And because the film is changed with digital system, then added the word and become Digital Single Lens Reflect or DSLR. Lens of SLR camera can be replaced easily with many different types, and the viewfinder is always seeing through the same lens with shooting lens. Now the digital SLR no longer use a reflector mirror that can move quickly. There is only a viewfinder screen and large additional screen that receives the image through the shooting lens. Just an opinion: maybe the name can be changed to ‘Digital Interchangeable Lens camera’. The figure below are DSLR cameras available at Amazon.

The prosumer camera is the type of camera which has ability between pocket camera and DSLR. The price is affordable and comes with a fairly sophisticated zoom lens and features that exceed the pocket camera. Below are digital cameras from Amazon with affordable price.

There is a type of camera called the Compact System Camera (CSC). This type combines a pocket camera with a DSLR, may be included in the prosumer class. CSC camera lens can be replaced like a DSLR camera. Another name for CSC camera is mirrorless camera, because this camera has no longer used a mirror to see from the viewfinder like DSLR. Because it combines compact camera and DSLR, the CSC camera is also called hybrid camera. CSC camera can record images with almost equal quality with a DSLR camera. Some photographers say that CSC can replace DSLR camera in the future. But currently CSC lenses availability are not as many as for DSLR. And because of different lens mounting, DSLR lenses can not be used for CSC.

Photo camera does have more facilities than the video to produce better still image. The main facility is the flash, which obviously can not be rivaled by the video. With flash we can make good photographs with less light or even dark.

Some camera have the red-eye reduction capability by turning on the flash before the photo is taken, and then turn on the flash again when the photo is taken. Light from flash is reflected by open wide eyes pupil causing eyes appear red when photographed. Light entering eyes through wide open pupils, light is reflected and passed through blood vessels makes eyes look red. By turning on the flash before the photo was taken to make eyes to adapt with the flash light and smaller pupils to minimize flash light reflection.

If you need to take pictures in low light without flash, then you need to test the camera before you purchase it by pointing to a dark place, for example in a dark corner of the camera store. There are cameras that can be tuned its ability to capture light, called ISO. The higher the ISO the more sensitive to the light. But the higher the ISO value, the lower the sharpness of the image due to the reduced number of pixels.
Some video cameras can be used to record with only starlight, but the picture quality is not very good. Usually the video image is green, when used with low light recording. You can make photo in the dark without flash with this video camera.

There are trail cameras available today that can be used to shoot automatically if there are objects, humans, or animals are passing in front of the camera. Trail camera usually is used to monitor security, photographing wild animals, and others. Trail camera is equipped with the ability to record at night. Also equipped with an infrared lamp as a light for night vision, the light is invisible to the human eye but visible to the camera. Trail cameras have very affordable prices, please check to Amazon stock below.

Zoom lens
Zoom lens is an adjustable focal length lens, in other words can be used as a telephoto lens to zoom in or to make objects look closer, and can also be used with normal focal length to view like real distance to objects. If set at telephoto position, the zoom lens will make distant objects closer, and narrow angle of view. If set to a normal focal length, the zoom lens will capture the scene or object like our eyes see the scene or objects, that is the normal angle of view. Some of the zoom lens can be set for a wide viewing angle (wide angle) and can be used to photograph the vast landscapes, but the resulting picture is somewhat curved, for example: the horizon line does not look straight but curved.

If a still camera equipped with zoom lenses that can be operated manually, not electronically with button, then we can make a photo with zooming effect. The resulting image looks like brush strokes from the center to the outside, it looks as if the object explodes when photographed.

There are two types of zoom capability: optical zoom and digital zoom, total zoom is a combination of both. Usually the seller describes only the total zoom. Actually we do not really need digital zoom, it is performed by an electronic or digital, and it can be done with the computer when we do digital editing. Weakness of digital zoom that it will lower the image quality when the zoom is too big. So we better rely to the optical zoom, the zoom that can be done by the lens, optical zoom doesnt lower image quality.

It should be noted that the camera with high zoom ability is sensitive to camera shaking. The recorded image will appear bluring when using high zoom and camera was shaking. These are effects that occur in telephoto lenses, where the point of view so narrow, and the distant objects looks closer. Little movement on the camera, eg a few millimeters, will create an object in distant move a lot, like moving a few meters as magnified by tele lens. So to prevent this you need to practice how to hold the camera zoom lens. The use of support such as tripod and monopod would be helpful. Tripod and monopod used by cameramen who are covering sports such as football matches. They have to capture moments from a distance of tens of meters and had to be enlarged with a telephoto lens or zoom, so monopod or tripod will prevent image shaking. Some cameras with powerful zoom lens, have digital feature to reduce the effect of camera shaking.

Some cameras are designed with a pistol grip model as the photo below, such as Sanyo, Panasonic, Polaroid, Aiptek, DXG, Spectra, SVP, and others. Cameras of this type are proofen to have less shaking as better grip by the hand. Suitable for use for outdoor activities such as sporting events, camping, and others. Some cameras are not designed with a pistol grip, but can be attached with a pistol grip handle that can be purchased separately.

The screen on the camera helps to manage the composition while shooting. Some cameras are equipped with a viewfinder in addition to having the screen, because the screen use much battery power. So if you need to save battery power, then use the viewfinder.

I prefer the screen with flip type as it can be positioned to help us to look at the screen. There is a flip screen that can be directed to the front of the camera, so you can photograph yourself and adjust the composition by looking at the screen from the front of the camera. Photo above shows the type of camera with flip screen is rotated to front, photographed facing the mirror, note the same hand and the same camera on the screen.

The screen also helps to see the results of shooting so we can retake the photo if the results are no good. With screen you can review and delete wrong photos in order to save memory. Some cameras have a photo editing features, you can edit photo with the help of this screen.

Sharpness or resolution of the image depends on dots or pixels that were recorded by camera software. The more pixels the better, but it will creat big image file and needs large memory. For a postcard-sized photographs measuring 3.5 x 5 inches or 89 x 127 mm, and it is called the 3R size, 3 megapixel camera is good enough. Today they are pocket cameras with more than 10 megapixels sharpness.

If you intend to make a detailed documentation for a natural scenery that can be enlarged, for example: you have to take picture of a hill with a variety of fruit trees. Later that photo will be used as documentation, and viewers can magnify images of that photo to see detail of trees on the hill and then enlarged again to see detail fruits on those trees. Then you need a camera with a very high resolution. Likewise, if you have to make landscape photos, model girl photos, etc., which will be printed very large, for example: to be affixed to a wall as wallpaper.

Some cameras can use common dry batteries that are available on the market, this type can also use rechargeable batteries that are available on the market. Some other camera use a special battery that can be recharged, these type of cameras can only use batteries designed for them. Choose the safest camera for you for long term use, do not rely on a cheap one but then you can not buy new battery.

Other Tips
Choose a digital camera that uses a storage container such as memory cards which are common in the market where you are. So you do not have trouble to add storage capacity. Choose a camera that uses a popular system to make it easy to share and print photos. You also need to ensure that the camera system does not conflict with your computer system. So you can store, display, edit, and print photos by your computer and your printer. Make sure the cable connections, such as USB, can be connected to your computer.

Today there is waterproof camera that can be brought to dive to depths of 12 meters or more. This waterproof camera is available with pocket type at a price slightly more expensive than ordinary pocket camera. This camera is also designed for shock resistant (shockproof). Suitable for covering activities in the wild.

And lastly, of course you have to choose a digital camera that suits your financial capabilities. Do not buy a sophisticated and expensive one as it’s technology could be obsolete within a few months, unless you really need the technology. You better buy the popular and not too expensive one. Because if many people are using it, it will be easy to share pictures, discuss with other camera users, easy to get accessories, and easily be repaired if damaged. If you want to resell it, the demand is hight so the price is not down too much. Popular products are usually have an easy and good warranty service.