Brake Master Cylinder Bench Bleed Tool [Archive]

mikey72

22-04-2011, 07:33 AM

Just did a quick search and found this guide:

http://0.tqn.com/d/autorepair/1/0/D/5/-/-/MC-clamped.jpg

You'll need steadiness to bleed the master cylinder. A bench-mounted vise is the tool for the job. If you don't have one, or don't have a bench at all, you can buy a clamp-on vise that can be removed when you're done. Just don't use the dining room table!

Mount the master cylinder on the vise, holding it by one of its dog-ear mounts. Be sure to mount it level so the air will leave and the fluid will refill properly during bleeding.

http://0.tqn.com/d/autorepair/1/5/C/5/-/-/bleeding-kit-installed.jpg

Many replacement master cylinders come with a cheap bleeding kit. It consists of two rubber hoses and two temporary plastic threaded inserts. If you opt to use the kit, you'll screw the threaded inserts into the output ports on your master cylinder (the ports on the side of the cylinder). Then attach the rubber hoses to the inserts and proceed to the next step.

If you don't have the bleeding kit, or don't feel like using it (my preferred choice), don't sweat it. You don't need it.

http://0.tqn.com/d/autorepair/1/5/G/5/-/-/rod-pushed-in.jpg

If you decided to go with the bleeding kit included with your replacement master cylinder, place the open end of the hoses into a receptacle to catch the brake fluid. If you aren't using the kit, read on anyway.

Be sure the reservoir is filled before you begin bleeding. You'll be using your wooden or plastic rod to push the cylinder in (the same way your brake pedal pushes it in while driving).

If you're using a bleeding kit, you're ready to start pumping. The trick is that you have to pinch the tubes closed every time you let the cylinder come back out. So, you'll push in, pinch the lines, let it out, let go of the lines, push in, pinch the lines ... and so on. You'll see lots of air bubbles coming out of the tubes with the brake fluid, and you'll see bubbles in the reservoir floating to the top.

Be sure to keep the brake fluid topped off in the reservoir. If it runs dry during pumping, you'll have to start over.

If you aren't using a bleeding kit the process is the same, only instead of pinching a rubber tube, you'll cover the holes tightly with your fingers when you release the cylinder. Keep pumping until there are no more bubbles floating to the top of the reservoir.

http://0.tqn.com/d/autorepair/1/5/F/5/-/-/ready-to-install.jpg

When you have pumped the cylinder until no more bubbles float to the surface of the reservoir, carefully replace the little caps that your master cylinder came with. Do this carefully, but don't fret if a small amount of fluid drips out. Screw the top onto the reservoir and your new master cylinder is ready for installation.

I would expect that if you could find out what size thread the cylinder has in it, you should be able get get a brass piece with the thread on one end and hose barb on the other. Then it's just a case of getting some oil/vac hose and make them yourself.

Also, make a little reservoir on the bench to catch the fluid lost in the process!

Hope this helps mate :)