Weeping master cylinder cover under gasket

[MWbirdLOVER70]

So 70 Plymouth Road Runner disc brake car and master weeping under gasket so looking for ideas to what might cause it or seal it. Tried my spare gasket and still some weep. Think cover bad. Ideas or open to buying a new cover if members have a clean one. Thanks guys

 

[davek]

post a pic I might have one for you. FREE

 

[MWbirdLOVER70]

Thanks bunches brother if it works!!!!

 

[MWbirdLOVER70]

Let me know it you need dimensions.

 

[davek]

Let me know it you need dimensions.

sorry mine does not match,good luck hope someone will help you out.

 

[MWbirdLOVER70]

Thanks brother

 

[4vnut]

You may possibly have a master cylinder that is rust pitted on the mating surfaces allowing for the weepage? Worth a look..

 

[MWbirdLOVER70]

Cap def had some but remember 53 years old

 

[71RRHI]

I had the same problem with the master cylinder on my 71. Couldn't find anywhere to buy just the cap and gasket. Went to napa and bought a new master cylinder for about $50. Didn't really want to change the whole master , so I took the new top, gasket, and locking wire and installed it on my old master. Fixed the problem and alot less work then changing the master and bleeding the system. And now I have a spare master cylinder if my old one ever goes bad

 

[MWbirdLOVER70]

I had the same problem with the master cylinder on my 71. Couldn't find anywhere to buy just the cap and gasket. Went to napa and bought a new master cylinder for about $50. Didn't really want to change the whole master , so I took the new top, gasket, and locking wire and installed it on my old master. Fixed the problem and alot less work then changing the master and bleeding the system. And now I have a spare master cylinder if my old one ever goes bad

Thanks for the idea and looks like that the way to go. Don’t think and repop places selling caps these days

 

[71RRHI]

Your master looks the same as mine, when I get home I can send you the part number. I think the new gasket and locking wire fixed it. It was alot harder to get the locking wire on after changing it

 

[MWbirdLOVER70]

I’ve been researching my cap and when I replaced the master years ago at the parts store the cap is a Ford cap but never seeped til this early summer (weird ) can you send dimensions width and length also please

 

[MWbirdLOVER70]

Your master looks the same as mine, when I get home I can send you the part number. I think the new gasket and locking wire fixed it. It was alot harder to get the locking wire on after changing it

Mine tight but inside looks pitted around edge

 

[71RRHI]

here the napa part number I used. The web site say's same part number for a 1970. Disc front, rear drum. But the price went up since last month. Web site shows $94. I paid $54 last month, but that might be due to I have a commercial account with my local Napa store.
I would say try it if it doesn't stop the leak then change the master. Mine was always wet but now bone dry.

 

[Cojohnso1]

What was some of the "Weepage" symptoms? Leak around cap? Air in brake lines with no sign of fluid leak?

 

[MWbirdLOVER70]

here the napa part number I used. The web site say's same part number for a 1970. Disc front, rear drum. But the price went up since last month. Web site shows $94. I paid $54 last month, but that might be due to I have a commercial account with my local Napa store.
I would say try it if it doesn't stop the leak then change the master. Mine was always wet but now bone dry.View attachment 1485485View attachment 1485486View attachment 1485488

View attachment 1485487

Thanks brother, I appreciate it

 

[MWbirdLOVER70]

What was some of the "Weepage" symptoms? Leak around cap? Air in brake lines with no sign of fluid leak?

Leak around the cap yes

 

[slepr1]

I use to have fluid leaking. I put the locking wire in a vice and gave it a little more angle. Leaks no more and a bit harder to lock in place. I figured that that wire must get a bit fatigued after many decades.

 

[MWbirdLOVER70]

I use to have fluid leaking. I put the locking wire in a vice and gave it a little more angle. Leaks no more and a bit harder to lock in place. I figured that that wire must get a bit fatigued after many decades.

Please describe better, I’m pondering that and winded if that it

 

[slepr1]

Please describe better, I’m pondering that and winded if that it

Take a look at how the wire clamp holds the cap on and determine which way you'd need to gently bend it so it applies more down force. (I made the 'V' part of the wire clamp a bit more narrow.) Then remove the wire clamp and lid. Clean the top surfaces of the MC and gasket of any debris. Put the wire clamp in the vise so that you can bend it. It doesn't take much. When you reinstall the gasket and lid, you'll notice its pretty hard to snap the wire clamp over the lid. If its too tight then you bent too much.