TR2/3/3A My theory about my clutch hydraulic problems

[Lukens]

I've mentioned in previous posts that I could not find the source repeating "soft pedal" and air in my clutch hydraulics. Here's what I think has been the problem:
I found the wavy spring washer in the MC broken, with a section completely missing. This would allow juice to be sometimes be pushed back into the reservoir instead of to the slave. When this happens I would rapidly pump the pedal which would be a source for air getting back into the cylinder.
I also see that my plunger did not have the rear seal on it (some diagrams show it with and some without?). I'm thinking this would allow the plunger to "****" a little in the bore and not seal properly, thus increasing the chance of drawing air.
I had a MC repair kit on hand from Moss, but I'm disappointed to see that the spring washer is not included... bummer. I'll have to get one before I can prove my theory.

Russ

 

[TR3driver]

FWIW, Girling deleted the rear seal and said to leave the slot empty.


https://i258.photobucket.com/albums...es/Girling Master Cylinder 2 raw.jpg~original

 

[Geo Hahn]

...I had a MC repair kit on hand from Moss, but I'm disappointed to see that the spring washer is not included... bummer. I'll have to get one before I can prove my theory.

Ah, automated censors. Difficult to think of a better word - maybe 'cant' or 'pitch'?

I'm pretty sure I can find that washer in my garage - PM me with your address if you want it.

 

[sp53]

Yes leave that rear seal off the plunger because if it does not have a perfect fit the piston will drag and the actual clutch will slip on the disc. I think the piece was only felt anyways perhaps to keep dust out of bore. I replaced one once with an O ring and caused problems.

 

[Lukens]

Ah, automated censors. .

Haha, it took me a while to catch that. Thanks for the offer, I may take you up on it.

 

[Lukens]

Randall, sp53, I'll leave the rear seal out.
FWIW when I applied air to the cylinder and pushed the plunger without the rear seal, it would leak if pushed off center. With the seal. couldn't get a leak.

 

[CJD]

It sounds like maybe the bore has been honed a few times too many if you are seeing enough slop to affect the seal. Might want to opt for a new MC instead of messing with worn out parts.

 

[Lukens]

It sounds like maybe the bore has been honed a few times too many if you are seeing enough slop to affect the seal. Might want to opt for a new MC instead of messing with worn out parts.

I'd agree accept I installed the MC new 2 years ago.

 

[CJD]

I'd agree accept I installed the MC new 2 years ago.

So the spring didn't even last 2 years...bummer! That is one of the reasons I prefer to re-use original parts when it is at all possible. It seems odd that the piston would be loose enough in the bore to affect the seal...possibly more quality issues with that MC?

 

[TR3driver]

And the bore may be oversize (or piston undersize) just from sloppy manufacturing. The original pistons fit the original bores quite snugly, so much so that they can be hard to get apart. With only a few thousandths clearance, the piston cannot tip enough to change the seal.

 

[Lukens]

And the bore may be oversize (or piston undersize) just from sloppy manufacturing. The original pistons fit the original bores quite snugly, so much so that they can be hard to get apart. With only a few thousandths clearance, the piston cannot tip enough to change the seal.

Understood. What's the negative to using the rear seal/

 

[CJD]

I think Randall mentioned that earlier...more drag can cause the piston to lag or stick when returning to the full out position. It's sort of a "Catch 22" situation. If the main seal leaks, the rear seal will prevent the fluid from escaping...but if the main seal does leak, the MC is already broke and needs repair.