Yes, another Brake Booster question...

[ryanO]

Okay, I've had a small brake fluid leak that I am unable to locate. I'm thinking it has to do with the master cylinder, but now I'm questioning the brake booster as well.

I've rebuilt the calipers and replaced the wheel cylinders. Next on the project list will be the SS lines...

Brakes function properly, and the pressure is good.

A few days ago I was cutoff and had to slam the brakes pretty hard. Once I had come to a stop and looked into the rearview to make sure people saw me, I noticed smoke coming from the tailpipe for maybe 10 seconds... It stopped smoking and the brakes still had good pressure...

I know that brake fluid smokes profusely when it's burned, and I think I somehow had some fluid get into the manifold...

Is it possible for the master cylinder to leak from the "plunger", down to the bottom of the booster (where the air hole is) and be sucked/or blown into the manifold?

No leak is visible from the front where the master meets the booster, but I'm noticing a small possible leak underneath the entire system...

Any tips or tricks would be most appreciated.

I have a new master ready for a swap, but I'd rather not need to replace the booster...

danke,

RyanO

[dlhoovler]

Is it possible for the master cylinder to leak from the "plunger", down to the bottom of the booster (where the air hole is) and be sucked/or blown into the manifold?

Yes, or so I've been told by several people. If it's not been doing this for too long, I think you can try to mop out the booster and hope for the best--but I think brake fluid is very harsh on the booster diaphragm (as it is on many things). Try replacing the master and be prepared that you may need a new booster down the road.

-Dave

[Mike Self]

If white, it may well be brake fluid; if grey, it could be sloshed oil from the panic stop.

Have you made sure that the brake fluid leak isn't from the clutch hydraulics? Check around the slave cyl boot; if you peel the boot back and it's wet, there's your leak. Also, use a pencil as a dipstick and see if there's fluid in your pedal box. A leaking clutch M/C will dribble into the pedal box (which will hold nearly a pint of fluid!) and eventually rust it out.

You should be alble to loosen the brake M/C bolts enough to slide it forward and get a finger (or a small flashlight) down into the booster to look for evidence of brake fluid there...and it'll be evident on the plunger end of the M/C when you disconnect it from the booster...

mike

[Guest Anonymous]

and was burning off before I started the restoration. I can't recall if there was any fluid in the booster or not once the project turned into a complete restoration. I couldn't find any other reason to explain how much hydrolic fluid I was loosing and I did have the white smoke esp on throttle lift from high RPM.

Gabe (in NJ)