Bench bleeding a brake master cylinder?
Thread Starter
Resident moron
Joined: Jun 2003
Posts: 4,746
Likes: 20
From: Assachusetts
Bench bleeding a brake master cylinder?
So I'm going to throw my new MC in tomorrow. Apparently you're supposed to bench bleed it first. I've got a Helms but I have no idea what it's talking about. Fashioning ISO flares? Fabricating plugs? What the?
Anyone got an easy way to do it?
Dope
Anyone got an easy way to do it?
Dope
Last edited by Dope; Jun 9, 2005 at 10:50 PM.
Le Mans Master
Joined: Aug 2000
Posts: 8,762
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From: Murphy TX
A true auto parts store (like Napa, not Autozone) should have a master cylinder bleed kit. It will have an assortment of all the standard fitting sizes etc.
Really what you need to do is screw something into the master outlets that you can then loop back into the resevoir (thereby using the master to pump fluid back into itself). So you need two fittings that can support a plastic bleeding hose.
Then two fittings that can serve as plugs that you can screw on while you're transferring the master to the car.
You should be able to get all this at a good auto parts store. If they don't have a kit it should be easy enough to find fittings you can slide a hose over. You can even keep those in while tranferring to the car and avoid the need to plug it up.
Hope this helps.
Really what you need to do is screw something into the master outlets that you can then loop back into the resevoir (thereby using the master to pump fluid back into itself). So you need two fittings that can support a plastic bleeding hose.
Then two fittings that can serve as plugs that you can screw on while you're transferring the master to the car.
You should be able to get all this at a good auto parts store. If they don't have a kit it should be easy enough to find fittings you can slide a hose over. You can even keep those in while tranferring to the car and avoid the need to plug it up.
Hope this helps.
Last edited by yellow01; Jun 9, 2005 at 10:12 PM.
Thread Starter
Resident moron
Joined: Jun 2003
Posts: 4,746
Likes: 20
From: Assachusetts
Ahh that sounds MUCH easier.
There's a pretty big auto store nearby that is owned by NAPA, think I'll check em out. The Helms has the correct fitting sizes so I should be good.
Thanks brother.
Dope
There's a pretty big auto store nearby that is owned by NAPA, think I'll check em out. The Helms has the correct fitting sizes so I should be good.
Thanks brother.
Dope
Le Mans Master
Joined: Dec 2001
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From: Winchester TN
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Hi Dope -
Yellow01 is right on the money -
I think the last several master cylinders I bought came with a bleeding kit.
The kit contains the previously mentioned two fittings (there are two sizes to keep folks from incorrectly installing the brake lines to the master cylinder), along with two short pieces of tubing, and finally, a small bracket that will hold the two tubes in place in the reservior.
I clamp the mounting flange in a vise (use wood blocks to avoid damaging the flange) and then fill the reservior(s).
Use a large phillips screwdriver or a 3/8 socket extention to slowly work the piston back and forth, pressing inward on the rear of the valve (looking at the back of the mounting flange).
Work the valve until you no longer see bubbles coming through the lines.
Be careful not to spill any brake fluid on the paint - it's not good for paint....
good luck!
best regards -
mqqn
Yellow01 is right on the money -
I think the last several master cylinders I bought came with a bleeding kit.
The kit contains the previously mentioned two fittings (there are two sizes to keep folks from incorrectly installing the brake lines to the master cylinder), along with two short pieces of tubing, and finally, a small bracket that will hold the two tubes in place in the reservior.
I clamp the mounting flange in a vise (use wood blocks to avoid damaging the flange) and then fill the reservior(s).
Use a large phillips screwdriver or a 3/8 socket extention to slowly work the piston back and forth, pressing inward on the rear of the valve (looking at the back of the mounting flange).
Work the valve until you no longer see bubbles coming through the lines.
Be careful not to spill any brake fluid on the paint - it's not good for paint....
good luck!
best regards -
mqqn
Safety Car
Joined: Apr 2005
Posts: 3,557
Likes: 2
Originally Posted by mqqn
I think the last several master cylinders I bought came with a bleeding kit.
The kit contains the previously mentioned two fittings (there are two sizes to keep folks from incorrectly installing the brake lines to the master cylinder), along with two short pieces of tubing, and finally, a small bracket that will hold the two tubes in place in the reservior.
