Power Brake Booster R&R?

[flathead6]

The master cylinder keeps slowly losing fluid in both reservoirs but with no obvious leaks anywhere. Doesn't this mean that my power booster is developing a drinking problem? What's the best replacement option and what's the going price on the unit?

Thanks,

KRB

 

[MSClair]

I had the same problem and i got a new boster and master cylinder at advanced for $115. 00 blead the brakes but couldln't get the ABS bleed screw out so i cut it out and blead the brakes Man what a huge difference. It will lock up all four no problem.

 

[dpuckett]

If your master cylinder is losing fluid, I'd look at it, not the booster. All the booster does is make the pedal easier to push down- it has nothing to do with the hydraulics. You caould have a bad seal in the master cylinder, or a leak somewhere down the line. I know, no fun, but necessary if you dont want to start Fred Flintstone stops.



Daniel

 

[Moab4x4]

In the past, when my rear master cylinder developed a leak into the booster I had some external evidence of that. I agree with daniel, check all wheel cylinders for leakage. Check near the block on the frame where your frame lines connect to the piggie tail lines that go to the master cylinder.

It is odd that both are going down.



How is your pedal? Does it stay firm or can you feel it leaking?



Could you have a gasket problem on the master cylinder cover? I did once and am a little embarrassed at how long it took me to find as it was the first I had ever seen it.

 

[flathead6]

If your master cylinder is losing fluid, I'd look at it, not the booster. All the booster does is make the pedal easier to push down- it has nothing to do with the hydraulics. You caould have a bad seal in the master cylinder, or a leak somewhere down the line. I know, no fun, but necessary if you dont want to start Fred Flintstone stops.



Daniel

Thats right, hadn't thought it all the way through I guess. If the MC is leaking through the shaft it goes into the booster and gets sucked up into the vacuum for the hydraulics right? Therefore disappearing.



Pedal stays good and hard, no leak off. ABS needs to go though, braking/stopping is very unimpressive and could use some improvement!



I will check the rest of the system real good again once things dry out here. I'll also clean up the MC and take a look at that gasket - never thought of that. Thanks for the tips guys.

KRB

 

[dpuckett]

ALso make sure you get your rear brakes adjusted. If they aint tight enough, you wont stop like you should, either. I adjust mine monthly to get a fair drag all the way around. "Self adjusting" means I gotta crawl under there and "adjust them myself," right?



-DP