71 Dart brakes

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71Swingerman

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Need some help here. I have new calapiers on the front with 74 rear with 10 - 2.5 shoes. The problem is I have brake fluid seeping out from under the master cylinder lid. The question is anyone have any idea why, is it the gasket, the master cylinder or the distrubtion/ perportioning valve?

Thanks:pale:
 
Some of these castings where the gasket sits are ruff and slightly uneven. It's best to use brake cleaner to completely dry the gasket and casting then make sure the bail wire is tight you can slightly bend it to make it tighter. The other thing you can do it take the master off and on a flat surface use a sheet of 100 or 120 grit and in a figure 8 sand the surface to smooth it out, be careful not to get casting dust in there.
 
Thanks, the pedal seems firm its just a bit hard to stop (no boster). I`ll try anything, its a pain with the thing leaking down on the exaust manifold.
 
The MC should have very little pressure in it. Other than checking for a good fitting ( new lid / reman res) don't fill past 1/4 inch front the top. Otherwise it's likely the seals on the piston bleeding pressure past them, and into the res. Check this by leaving off the lid pumping up the pedal, and push hard. Have someone watch for bubbles or rising fountains..
 
Thanks for all of the input. I will certainly check all of it out Its appreciated.

Thanks again.
 
My Duster was doing this, the rubber seal in the cover had tiny bits of rust sticking to it, cleaned everything off real good and it was ok, good luck.
 
Woodward said:
The MC should have very little pressure in it. Other than checking for a good fitting ( new lid / reman res) don't fill past 1/4 inch front the top. Otherwise it's likely the seals on the piston bleeding pressure past them, and into the res. Check this by leaving off the lid pumping up the pedal, and push hard. Have someone watch for bubbles or rising fountains..
Click to expand...

DO NOT pump the brakes with the top off,, unless you want brake-fluid all over your paint!!

Brake fluid is excellent paint remover,, rinse with water immediately if you do get any on paint you care about..

If there is no irregularity in the mating suface,, and the seal seem okay,.. I've found that air trapped in the brakes can violently shoot a fountain of br fluid back into the reservoir, up against the rubber gskt,, and migrate under the lid..

With the rear brakes properly adjusted,,, set the emerg brake,, have someone pump the brakes and hold them down,, THEN take the lid off,, and watch the fluid as the pedal is released..

If you have a "fountain" of fluid returned,, especially in the disc reservoir,, then you have air in the brakes that is compressing when applied,, and "springing" fluid back to the reservoir when released...

Poorly adjusted shoe style brakes can cause a similar return,, as the springs return the shoes,, but should be negligable if brakes are adjusted properly..

hope it helps
 
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