Missing brake fluid

[old guys rule]

No problem with brakes till now on my 63 b-body. All drums. Pulled out of the garage yesterday and the brakes failed. Open the master cylinder and the chamber for the front brakes was empty. I see no leaks anywhere. Power assist drum?

 

[Aron Gleason]

Leaking out the plunger down the inside of the firewall where you can't see it. If you look where the plunger goes in to the master cylinder under the dash it should be wet.

 

[Mopar Hunter]

I had one leak into the brake booster.

 

[old guys rule]

Thanks I'll check tomorrow

 

[1 Wild R/T]

Leaking out the plunger down the inside of the firewall where you can't see it. If you look where the plunger goes in to the master cylinder under the dash it should be wet.

Power brakes so it won't be running down the firewall... It'll be inside the booster...

 

[Nate S]

Many people don’t know that this stuff simply evaporates too (very slowly). If there’s a little leak in the rubber seal over the reservoir it’ll just evaporate away over the course of a year or two. Had a ‘55 C1B pickup for a decade or so. That was before the rubber seal. The filler plug had a little hole for venting (so not sealed). Once a year I had to refill the MC. No leaks anywhere. System worked great.

 

[Ron_M]

I was recently educated that it evaporates as well. I still find it hard to believe.

The leaking into the booster seems more logical, though disturbing.

 

[old guys rule]

Many people don’t know that this stuff simply evaporates too (very slowly). If there’s a little leak in the rubber seal over the reservoir it’ll just evaporate away over the course of a year or two. Had a ‘55 C1B pickup for a decade or so. That was before the rubber seal. The filler plug had a little hole for venting (so not sealed). Once a year I had to refill the MC. No leaks anywhere. System worked great.

Thanks. Now I have something to hope for.

 

[RemCharger]

I take a long zip tie and check it like a dipstick.