Leaky clutch master cylinder

[CJG]

Hi everyone,

 

I'm afraid the old girl is still dripping DOT4 - something I need to get sorted before I have the bulkhead resprayed!!!

 

The brake master cylinder (which is about 8 months old) seems OK, but I've noticed fluid oozing from around the cap of the reservoir on the clutch master cylinder (which is about 48 years old). The question is - is it enough to replace the seal at the top of the reservoir? Is the system likely to be overfilled? If I need a new cylinder, where can I get a reliable unit of decent quality? The problem occurs primarily after long runs, particularly when there is a lot of heat in the engine bay.

 

Finally, what precautions can I take when the car is stored for 3 years to prevent the seals from giving out and causing another catastrophic loss of fluid? I fear draining the hydraulic circuits will allow everything in there to rust solid.....

 

Regards from (still) Düsseldorf,

 

 

CJG

[RogerH]

my cap has always had a weep/seep of fluid - can't stop the bl**dy thing.

To stop fluid running on to the the bulkhead I put a screwed up piece of cleaning cloth under the cylinder and change it every couple of weeks. I have 2 Pack paint so no problems about paint lifting but the cloth ensures that fluid isn't on exposed areas.

 

Roger

[stuart]

PTFE tape on the cap thread

Stuart.

Edited August 2, 2010 by stuart

[RogerH]

.....wish I had thought of that...

 

Roger

[TR 2100]

PTFE tape on the cap thread

Stuart.

 

Surely that would have an effect only if the fluid was finding its way

down the threads, and surely an effective cap seal would prevent that.

 

Maybe the fluid is coming out of the vent hole in the cap?

(but just looks like it's coming out of the threads)

 

AlanR

[CJG]

Surely that would have an effect only if the fluid was finding its way

down the threads, and surely an effective cap seal would prevent that.

 

Maybe the fluid is coming out of the vent hole in the cap?

(but just looks like it's coming out of the threads)

 

AlanR

 

 

Thanks, Alan.

 

Just one question, though. If it's coming out through the vent hole, how do I stop it? Does that mean the system's overfilled?

 

Regards,

 

CJG

[dykins]

.....wish I had thought of that...

 

Roger

 

 

 

You will Roger

 

Regards

 

Peter

[stuart]

Surely that would have an effect only if the fluid was finding its way

down the threads, and surely an effective cap seal would prevent that.

 

Maybe the fluid is coming out of the vent hole in the cap?

(but just looks like it's coming out of the threads)

 

AlanR

 

That is precisely the problem it does come out of the thread. I had the same problem with the brake master on my 4a and changed the lid several times until I eventually found one that was a reasonable seal as its the thread that the fluid migrates down despite a rubber seal at the top. Even then it still benefits from PTFE tape . Just poor manufacturing tolerances. I do remember they werent that good on most cars when new.

Stuart.

[CJG]

That is precisely the problem it does come out of the thread. I had the same problem with the brake master on my 4a and changed the lid several times until I eventually found one that was a reasonable seal as its the thread that the fluid migrates down despite a rubber seal at the top. Even then it still benefits from PTFE tape . Just poor manufacturing tolerances. I do remember they werent that good on most cars when new.

Stuart.

 

 

Thanks Stuart.

 

On which side should I put the tape: on the reservoir or on the lid?

 

Regards,

 

CJG

[stuart]

Thanks Stuart.

 

On which side should I put the tape: on the reservoir or on the lid?

 

Regards,

 

CJG

 

On the reservoir.

Stuart.