Master cylinder lid leaking

[Radiohead]

The truck has a hydro boost behind the master if that makes any difference. Any advice is greatly appreciated!!!

Hydroboost.
Man said hydroboost.

Question for the braintrust here - Could it be defective in a fashion allowing pressure to be in the reservoir? Thus expelling fluid via lid upon activation? Just spitting balls here...

 

[squaredeal91]

Yeah, Its happened to me before. Sealing surface on master gets rust pitted and won't seal again till its resurfaced.

 

[RamblinGMC]

Hydroboost.
Man said hydroboost.

Question for the braintrust here - Could it be defective in a fashion allowing pressure to be in the reservoir? Thus expelling fluid via lid upon activation? Just spitting balls here...

That is exactly what I was thinking! But a new master seems to have solved the problem. I'll drive it more this week and know for sure.

 

[RamblinGMC]

Yeah, Its happened to me before. Sealing surface on master gets rust pitted and won't seal again till its resurfaced.

A new master solved the issue! Thanks for the ideas!

 

[RamblinGMC]

A new master seems to have solved the problem.

 

[Blazerbiker]

We often put a hose clamp around the whole master to clamp the lid down better so they don't leak when we're at funny angles offroad. It seems a little butch but solves the problem.

 

[JBswth]

I had been driving it for several years and never opened it. It just started leaking. It was half empty when I checked it, topped it off to about 1/4" from the top. I doubt the level has anything to do with it. Something odd is going on.

Driving it several years and never opened it??? You are lucky it never got low enough for you to have no brakes. You are supposed to check your brake fluid regularly - every time you get gas. "Taking a chance" on brakes and/or related items, can cost you your life.

J. B.

 

[RamblinGMC]

Driving it several years and never opened it??? You are lucky it never got low enough for you to have no brakes. You are supposed to check your brake fluid regularly - every time you get gas. "Taking a chance" on brakes and/or related items, can cost you your life.

J. B.

I do check for leaks and the condition of pads/shoes regularly. So no need to pop the lid if there are no leaks.

 

[YakkoWarner]

I'm in the "check everything all the time" camp - if anyone is with me they go crazy when I stop for gas because I'm checking that can be without breaking out tools (brake master, oil, transmission (if possible), steering fluid if applicable, coolant, looking for anything unusual or apparent leaking). Not all leaks are immediately visible, but a level change in a fluid usually indicates its going or coming from somewhere.

 

[RamblinGMC]

I'm in the "check everything all the time" camp - if anyone is with me they go crazy when I stop for gas because I'm checking that can be without breaking out tools (brake master, oil, transmission (if possible), steering fluid if applicable, coolant, looking for anything unusual or apparent leaking). Not all leaks are immediately visible, but a level change in a fluid usually indicates its going or coming from somewhere.

Very true!

 

[JBswth]

I do check for leaks and the condition of pads/shoes regularly. So no need to pop the lid if there are no leaks.

As the linings wear, fluid level drops, so you should indeed check the level. Ignore it at your own risk.

J. B.