MGB STILL working on clutch slave

[GaryBeu]

So this is another case of not knowing what I don't know . I have one of those vacuum brake bleeders and I'm trying to bleed the air out of the slave cylinder...I've bled it over and over and kept the reservoir at least 1/2 full but I'm still getting large amounts of air. Does someone need to hold the clutch in constantly or am I getting an air leak from somewhere? This is a new slave cylinder. Suggestions??

 

[trrdster2000]

Gary, I have used the vacuum bleeder to get the fluid to the area to be bleed but not much luck getting it to get the air out. Use the old way, push the pedal down and open the bleeder keeping the tube in the cup and under the fluid to look for air, close the bleeder , pump a couple of times and repeat as often as needed. It's a two person job, the wife of course.

 

[GaryBeu]

Thanks...I'll try that. My wife is a better mechanic than I am in some cases

 

[PAUL161]

Gary, I solved that problem a few years ago. I feed the fluid from the cylinder end pushing it up into the reservoir with a pressure fluid tank. You can use an old basting bulb to extract excess fluid or an liquid suction device from the reservoir. A little bit of Teflon tape on the bleeder threads helps it from leaking while pushing the fluid. I fill new brake systems the same way and eliminate 95 percent of the air on the first push of fluid. Just make sure someone is watching the fluid level! PJ

 

[Boggsy64]

I have a MityVac hand vacuum pump and I could pump until my arm fell off and the bubbles just kept on coming! Finally rigged up a venturi system to use my shop vac to generate vacuum. With this I was able to finally get my brakes to bleed to an acceptable level. I have given up using the hand pump in any bleeding application, because I am sure the air was coming from around the bleeder nipple. For any bleeding application from now on I will use the two person method, or a pressure method to push the fluid back to the reservoir.

 

[bob67bgt]

When you get a new cylinder the bleeder is usually in the wrong hole. Be sure its in the correct hole or it will be very hard to get all the air out. Bob

 

[DrEntropy]

Bob is right. The bleeder should be in the higher of the two holes.

 

[bob67bgt]

Also when I am finished bleeding with the pedal I push the piston back into the slave with the bleeder open and then close the bleeder then the piston bottoms out. This gets any extra trapped air out. Sometimes its a real fun job! It will take a few slow strokes to feel resistance again. Always bleed with slow pumps as this gives the cylinder time to refill and not suck air in. The pumper must be patient.
Bob

 

[Sarastro]

These are all good ideas.

The clutch is notoriously difficult to bleed, and I've had precisely zero luck using a vacuum bleeder. Air gets sucked in around the bleed screw's threads, maybe other places as well. I found that doing it the old fashioned way, with my wife working the pedal and me the bleed screw, worked well. This was on my Bugeye Sprite.

Also, the slave cylinder I bought had the bleed screw on the bottom, which is lunatic. Even after putting it in the right place, it was difficult. I had to loosen one screw on the slave cylinder and tilt it so the bleed screw was really at the highest point.

 

[DrEntropy]

I use an Eezi-Bleed (Gunson) and it works every time, no issue.

 

[drooartz]

I use an Eezi-Bleed (Gunson) and it works every time, no issue.

I picked up one of these to do the clutch on my old MGB last year, worked like a charm.

 

[GaryBeu]

I need to find an Eezi-Bleed (Gunson)...

 

[DrEntropy]

EBay, Gar.

 

[GaryBeu]

Thanks Doc...

 

[GaryBeu]

I looked on Ebay...is there a specific model of the Eezibleed that I should get? Will just the cheapest one do the job? Thanks.

 

[Bob Claffie]

Gary, the only thing you have to do is match up the threads to the slave bleeder hole. Otherwise cheapest is best. Bob

 

[DrEntropy]

If it's the Gunson Eezi-Bleed kit G4062, that's it. It will have the different sized master cylinder caps to fit a variety of cars. Never found a European system it didn't fit... but never tried to do any Japanese car with it. :wink:

 

[GaryBeu]

Thanks Doc...looks like they all ship from the UK. I'll keep looking.

 

[Brinkerhoff]

Gary, I've never used an EZ bleed. The procedure is to pump the pedal a few times and hold it down, open the bleed screw and let the air out , close the bleed screw , let the pedal up. If you don't have another helper cut a piece of 2x4 to hold the pedal to the floor while you are under the car opening and closing the bleed screw. If the piston in the master cylinder returns back to the top , you'll have it bled in 10 minutes. The problem usually is that the master cylinder piston won't return enough the allow new fluid to refill the chamber so nothing squirts out the bleed screw. Tapping on the master cylinder body usually will fix this. This can add to the difficulty until some pressure is built up.

 

[GaryBeu]

Carla and I are planning to do exactly that this afternoon. Carla is in the process right now of bringing home a new horse