What would cause this?

[Hemidog]

My MP aluminum master cylinder reservoir leaks in the front.
The reservoir is half-full, so I don't think the leak is caused by overfilling? I've seen this on other MP alu cylinders (Joflaig?) I complained to the seller that the caps was warped, and he sent me new ones, but that did not help  
I can clean the reservoir, and one trip later it looks exactly the same.


Any ideas?

[elacruze]

Stupid question-

Is there a gasket in the front cap?

[Hemidog]

Stupid question-

Is there a gasket in the front cap?

Yep, I even put a extra rubber gasket underneath the original gasket on the old cap, but it didn't help.

[HOTROD]

Small crack ??

[Hemidog]

None that I could find, but I will check again.

But could there be something wrong with the brake system or cylinder? Seems like the cylinder squirts brake fluid underneath the front cap hard.

[Hemidog]

No cracks, but the caps are warped AGAIN!
I'm definitely not going with this type of MC again, does anyone else have the same master cylinder?

[Rubberduck]

Good to know. I considered to get me one.

Mario

[charger Downunder]

Swap the caps around and see if it leeks out the back one.
Is the cap tightening down level it looks like its down at the front and up at the back.

[Hemidog]

Swap the caps around and see if it leeks out the back one.
Is the cap tightening down level it looks like its down at the front and up at the back.

The rear cap is not as warped as the front cap, and yes the caps are unevenly tightened down due to the warping.

[resq302]

Looks to me like you have some heat issues there.  From the looks of the master cyl core, the alluminum housing seems to have been clear coated and exposed to some serious heat causing the brownish discoloration.  I would suspect that your front master cyl. cap is getting warped from the extreme engine temps under the hood.

[Hemidog]

Looks to me like you have some heat issues there.  From the looks of the master cyl core, the alluminum housing seems to have been clear coated and exposed to some serious heat causing the brownish discoloration.  I would suspect that your front master cyl. cap is getting warped from the extreme engine temps under the hood.

The aluminum looked like that when it was new, and I don't think I have a heat issue under the hood.

[NYCMille]

Dude, I have the same issue with the Daytona. I've tried different cap, new gaskets etc... and right now I have not been able to cure it. I also run the same exact set-up on the Charger and have never had an issue.... Unfortunately I don't have an answer for you on this as I'm trying to figure it out myself.

[Wicked72]

What it looks likes to me is blow by. There must be excessive pressure in the reservoir. Even thou there isnt enough to reach the top, when you drive it will splash and run down. So something is causing some pressure making it blow past the gaskets.

In the pic the cap appears to be tilted as if the reservoir has expanded.

[charger Downunder]

What would happen if you drilled a little breather hole in the top of the cap.

[b5blue]

Though I'm not familiar with that booster system I do know if the plunger for the master can't return all the way back to a home resting spot for the next stroke it will "act" like bypass, pumping fluid oddly. Is there a depth adjustment from the booster to the masters plunger?  (On vacuum booster power brakes there is a rod with a nut on the end to set depth into the masters plunger.) 

[Back N Black]

looks like a chevy M/C, maybe try caps from a chevy dealer. 

[elacruze]

I searched the forums and found this thread, because after 2 years my M/P master cylinder started leaking from the rubber seals between the plastic reservoir and the aluminum body. I was thinking that the seals shrunk up, but more likely they just got too hot too many times. My caps don't leak, though...

Anybody have a good heat shield source for the 2-bolt master cylinders? I have a very good Aluminum fabricator locally, I may work something up and have some made.

I see now that M/P actually sells a stainless steel heat shield. <sigh>

[firefighter3931]

Anybody have a good heat shield source for the 2-bolt master cylinders? I have a very good Aluminum fabricator locally, I may work something up and have some made.

I see now that M/P actually sells a stainless steel heat shield. <sigh>

http://chucker54.stores.yahoo.net/mascylheatsh.html

[Big Sugar]

You can get one from your local Chrysler dealer, thru the Mopar Performance catolouge,  just got one ordered in and it arrived in 2 days, $35 Canadian.....may seem steep $$ but its a nice piece .


Ron

[Big Sugar]

Is a replacement resevoir available ?   




Ron