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Fluid leak help.

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vagt6

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Hello, all. In my '74 MK III Midget I've recently noted a very slight leak of what seems to be brake fluid on the rubber floor mat. It's dripping down the clutch pedal from above, originating from a brake master cylinder, possibly.

I took the top cover off the pedal box but saw nothing obvious. This car was restored about 10 years ago and there was plenty of lithium grease on the clevis pin, etc., and it looked clean. There was a little bit of fluid on the dust boot.

Most importantly, neither cylinder fluid level was low, they both looked full with clear fluid.

So, what's the diagnosis? A very slow leak from somewhere. It doesn't appear to leak unless I'm driving (not while sitting still) and then, only a little bit.

Thanks, guys. :thumbsup:
 
Leaking down the pedal like that is a sure sign of a master cylinder leaking. Unless you have filled it recently and spilled some- i would say it is telling you it will need some attention soon.

m
 
I'm gonna try the Moss master cylinder "Repair kits" (180-205 & 180-905), maybe I'll get lucky.

Guess I should do a repair kit for each master, just to perpetuate the "while I'm at it" syndrome.

Suggestions are welcome, I have the repair manuals and any input is most welcome regarding this seal replacement.

Many thanks! :thumbsup:
 
That tandem cylinder is a bear to rebuild. Better search the archives before starting on it.
 
The clutch master is pretty easy to rebuild, it is the brake master that is a bear.
BillM
 
Have any of you "lucky" guys ever done this overhaul using the Moss repair kit?

If so, please share your experience. I need some motivation!

Thanks!
 
Trevor Jessie said:
That tandem cylinder is a bear to rebuild. Better search the archives before starting on it.
Click to expand...

At the risk of sounding naive.... it looks pretty straight forward. What am I not seeing?
 
One man's blue sky is another man's rain, Mark. :lol:

Apparently an easy project for you, so please share your experience here as it would be most appreciated. Just looking for input from those with experience ith this particular project. Also, if you know of any on-line tutorials or articles, please share.

I've never done this before, and there are myriad tiny parts to assemble. The manuals are not exactly effluent on the process, either and the Moss kit provides no directions.

Anyone who has experience with such a project is most welcome to share it here. Photos, narratives, experiences, pitfalls, whatever.

Many thanks for all the input! :thumbsup:
 
vagt6 said:
Have any of you "lucky" guys ever done this overhaul using the Moss repair kit?

If so, please share your experience. I need some motivation!

Thanks!
Click to expand...

OK, here is my description from when I did it. This is a job that appears way more intimidating than it really is (trust me). In reality, with the kit you are looking at an easy evenings project. One thing I didn't mention is check for pitting inside the cylinder - if it is, that's a problem but I don't expect you will. Also, I later took off the switch assembly and cleaned it also - it was full of cr*p. Also took off the "side bolts" (where the lines attach) also dirty.

BTW - don't forget brake fluid eats paint if you need incentive.
MC rebuild
 
JP, thanks, that's just the kinda stuff I'm looking for.

The Haynes manual refers to a "circlip removing tool". Is is essential? There appear to be at least two circlips that must be removed and replaced: can I do it with needle nose or similar?

Again, many thanks for this great input, JP.
 
I bought a circlip removal tool for a couple of reasons.

1. they're cheap.
2. One of those times that having the right tool makes life waaay easier.
3. They are a "men from the boys" addition to your toolbox. People will ask, "what is that?" and you can answer, "It's a circlip tool." (insert Tim Taylor noises here)
 
:blush: let us know how it goes
 
Ahhh, excuse me is that an inside or an outside circlip tool?
 
jlaird said:
Ahhh, excuse me is that an inside or an outside circlip tool?
Click to expand...

bought the kit - both
grin.gif


(though inside is needed)
 
Yeah but is it long enough to reach all of the way down to the bottom of the bore to getthat second seal out that is way, way down there?
 
vagt6 said:
One man's blue sky is another man's rain, Mark. :lol:

Apparently an easy project for you, so please share your experience here as it would be most appreciated. Just looking for input from those with experience ith this particular project. Also, if you know of any on-line tutorials or articles, please share.

I've never done this before, and there are myriad tiny parts to assemble. The manuals are not exactly effluent on the process, either and the Moss kit provides no directions.

Anyone who has experience with such a project is most welcome to share it here. Photos, narratives, experiences, pitfalls, whatever.

Many thanks for all the input! :thumbsup:
Click to expand...

I've actually never done the job myself. when I was stationed at Travis AFB by Sacramento, I contacted Gerard(Gerards garage)and ran down to his place in San Francisco to get his opinion of my tandem master cylinder; as I bought the car with disk brakes already installed and had recently read his description of the 3/4 vs. 7/8 master cylinder differences and their effect on disk brake conversions. anyway to make a long story short, he pulled my master cylinder all apart in about a minute, checked everything out and re-assembled it in about two minutes! Maybe it was just him that made the job look easy! Nice guy if you ever get the opportunity to meet him BTW
 
Right on with the exchangeable jaws.
 
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