TR2/3/3A TR3A -- Vacuum Bleeding Girling Brake System

[deadair]

I recently got a vacuum bleeder and tried it on my TR3A last weekend to bleed the brakes. I noticed that the bleeder was not extracting sufficient fluid from the system. It was as if there was some blockage at the master cylinder. Depressing the brake peddle resulted in the expected amount of fluid.

So, I'm thinking that maybe the girling master cylinder might be designed so that you can't extract fluid at a brake cylinder or caliper from the reservoir with the peddle in the up (none-depressed) position. Is this true? If so, is the solution to use a piece of wood, or something, to keep the peddle depressed?

 

[ekamm]

I don't know or sure,but that seems to make sense.

 

[vettedog72]

I guess you still need two people to belled the brakes with that system. The ball and spring tube is hard to beat for a one person brake bleed.

 

[Mkutz]

I had the same problem on my TR3. I was never able to extract much fluid using the vacuum kit and reverted to the old pump-hold-release-retighten process.

 

[HerronScott]

My wife hates being the second person in that process.

"OK, pump, pump, pump and hold..."

I'm pretty sure she would be ecstatic to never hear that again...

Scott

 

[rjc157]

buy speedy bleeders the easiest thing yet and they work

 

[deadair]

So nobody here has successfully used a vacuum bleeder on a TR3?

 

[deadair]

Seriously? Nobody has a clue?

 

[tdskip]

Why wouldn't this work? My guess - and I'll clearly defer to Randall and others - but I'm not aware of any valve that would prevent this....

Did you try the other side yet? Does fluid move when the brake pedal is pushed?

 

[TR3driver]

There doesn't appear to be anything in the design that would deliberately keep it from working; but it didn't work for me either. Depressing the pedal makes the problem even worse, as that deliberately closes the valve to the reservoir.

I'd blame the RPV, but since mine is disabled, I don't think that is it either.

I also had trouble with it sucking air past the bleed screw threads.

Since switching to DOT 5 I rarely have to touch the brakes anyway ... easier overall to bribe someone into helping IMO. Dinner for the wife, or a piece of watermelon for a neighborhood kid. Actually, the wife seems to enjoy the chance to help, when there is no chance of getting her hands dirty

 

[HerronScott]

Randall,

I think Kym hates it because it's too menial. She and I have pulled a number of engines and transmissions as a team and I fondly recall her rebuilding the Mazda RX7 carb.

Scott

 

[deadair]

Why wouldn't this work? My guess - and I'll clearly defer to Randall and others - but I'm not aware of any valve that would prevent this....

Did you try the other side yet? Does fluid move when the brake pedal is pushed?

No, I haven't tried that yet, but based on what Randall says, it appears that won't work. This is a curious problem that challenges my brain cell.

 

[wingsandwheels]

I strongly recommend a pressure bleeder. I have the Motive Power w/ the universal and European adapters and just flushed the TR's brakes after installing a new m/c.

I have never had much luck vacuum bleeding my TR's, typically the front discs will bleed ok after some effort, but the rears never seem to flow enough and there are always air leaks from the bleeder threads....I had to learn to to "read" the bubbles to distinguish those from the circuit vs. those from the threads. It can be done, it just takes way too long and way too many squeezes of the mityvac.

Even with the pressure bleeder, the rears still do not flow that much as compared to the fronts and it took at least 8-10psi to do the job, by contrast other cars I've done will get a good flow at just above 5psi.

good luck, w

 

[deadair]

Ok, I ordered a "Motive Products Power Bleeder - European- Black Label." It sucks (or in this case, blows) to have to experiment with a variety of bleeders to find the one that does the job correctly.

I'll report on my experience and hope the next person can benefit from it.