Is the front reservoir in the master cylinder used for the front or rear brakes on a 93 CTD?

 

The larger reservoir serves the front disc brakes. The smaller reservoir serves the rear drum brakes.

 

The 93 is loosing fluid from the small reservoir and I have replaced both rear wheel cylinders. I can't figure out where the fluid is going. Any ideas? Also the brake dashlight is on, but brakes are working great.

 

Into the vacuum booster.

 

Is this a common problem?
How do I check for this?
Is a new Vaccum booster required?
The pedal effort seems to be normal.

 

Yes.
Pull the master off, the booster will be wet behind it.
Yes.
The brake fluid hasn't eaten the diaphragm - yet.

 

Thanks, I will check the booster out.

 

Stinky!

So with my recent brake system overhaul, and installing the rebuilt master cylinder, I've most likely tweaked the OEM diaphragm so it's sucking brake fluid from the new MC?

 

I don't see how you would have done that? The booster won't take out the master, it happens the other way 'round.

 

I can't believe I'm typing this but I believe I'm loosing brake fluid from the MC/Lid interface when I launch really hard.

Just before installing the rebuilt unit, I painted it all nice and purdy. I've a number of streaks now coming from under the MC lid.

It's either a poor seal which I can't seem to identify,

Or,

The new rear disc brakes are slugging fluid, . . . . .. or something.

 

I'd try another lid.

 

I have replaced mine a couple of times. The only place I could find one was the dealership. The price was not to bad, NAPA had no clue.

Jim

 

just a note, the diaphram in most boosters is resistant to brake fluid (kinda like the boots on the wheel cylinders). it's almost like they figure brake fluid may end up in there.

 

ok I am having the same problem, the dealership told me it was the master cylinder so I replaced it myself with a reman one from napa, and guess what, it is still leaking only now on the new one I can see it is coming from under the lid. The clip is super tight already and I don't think i can get it much tighter. So I don't have any more Ideas. it is a new master and cap and gasket and still leaking. Any help you all could offer would be appreciated.

Is there a different upgraded gasket that can be bought for it?