Brake Mystery!

[Rockcrusher]

A couple of three weeks ago during my weekly fluid check I popped the top off of the master cylinder and found the rear reservoir close to empty. Not a problem . . . I filled it up, then crawled around under the truck looking for any signs of a hydraulic leak. I didn't find any wet spots on or around any of the lines and none of the wheel cylinders were drooling so I went on my merry way.

This morning while doing my weekly thing, I found the MC nearly empty again (less than ¼" in the rear reservoir). Again, I crawled around looking for leaks and again I didn't find any. I don't have power brakes so the fluid isn't getting sucked into the booster but where the hell is it going? I want to fix the problem but I can't fix what I can't find.

Any suggestions . . . Anyone experience a similar problem?

[68F250]

If your brake lines are plumbed correctly, the rear reservoir feeds the front brakes and the front reservoir feeds the rears.

Look inside the cab where the mc sticks thru the firewall and see if it's wet and running down the firewall, pull back the boot and check for wetness too. If you don't see anything then I'd pull off the front drums and take a look.

[crazy larry]

park it and with no motor running, pump up the brakes and hold for a minute or two. then take a peak underneath. might help, might not....

do you use ez bleed screws? i found my pass. side was loose, just enough to leak under pressure....

[lobuck76]

I would check the interior side of the firewall

[heep70]

Did you find it?