recently purchased a 2004 2500HD 4x4 duramax, runs like a champ, drives great, better then my old powerstroke, but after one night being parked in the driveway, i noticed a puddle which i first thought was oil. after tracing the leak, i foung out its coming from the brake master cylinder. it doesnt look to have ever been worked on before. i noticed its a two piece cylinder, is there a gasket in there that possibly has gone bad, or an o-ring gone bad? i need to know whats in there before i order parts. thanks for the help yall

 

mine leaks too, but never enough to make a puddle, not sure what the repair procedure is on that....

 

Is it brake fluid or power steering fluid? If it's off the back of the master cylinder it could be either/or, and more than likely it's ps fluid off the hydro booster.

Is brake fluid low? or power steering fluid low?

 

do both ps and brake run off the master cylinder? it leaks right wear the two parts join, in the seal. cant tell if theres a gasket there or not? both fluid levels seem within range. brake fluid is over full due to the dealer adding too much, which makes me assume it was low at one point for them to add too it.

 

there is no gasket or seal between the booster and MC. Both are sealed themselves as the MC controls the brakes using brake fluid and the booster controls the power assist and uses ps fluid.

You can pull the 2 nuts that hold the MC to the booster and move the MC out and up to get a good look at both. I would clean and dry both pieces and then start the engine to see if you can see ps fluid coming out of the bosster shaft.

 

so would the repair be buying a whole new booster since there are no gaskets between the two?

 

if it were me, i'd just clean up around the mc real good, maybe even leave a rag under or around it to absorb fluid if more should come out. keep an eye on the fluid levels from time to time, maybe the dealer over filled the system and the excess must go somewhere. also look around the power steering hoses and insides of your tires for wetness as a sign for a leak. i'd hate to start throwing parts at something and find out its the wrong part.

 

Allright, ill clean it up and keep an eye on it. It's been dripping down onto my frame rails which sucks because its now pealing the paint off.

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