Retarded Brake Question

[raoul.duke]

OK, yeah, I'm new. Let me preface this by saying that I've never done any brake work before.....had the truck for about 2 months but haven't messed with 'em yet....

Took a hard left in the '72 on Saturday and the brake light came on, but the brakes seemed to be working fine. Made it home, assumed the light was grounded from something I had done in the dash that day.

No dice- opened the master cylinder- the front reservoir was overflowing but the back one is bone freaking dry. I assume this is not normal.......no leaks- should I just fill the backside and bleed or is there something else going on?

thanks

[TugOwar]

you can refill and bleed if you want to keep driving, just keep a check on the fluid in the future. But you definately have a leak somewhere. Brake fluid doesn't evaporate.

The rear reservoir is for the rear brakes so that should help narrow down where it may be leaking.

Welcome to the board from south TX and for Gods sake post some pics of your truck if you haven't already!

[truckdude239]

it sounds like the master cyl;ider has gone back and is transforing the fuild from the rear part to the front you will need to replace th mastercylider

[Green Machine]

Yep, internal MC leak, time for a new one.

[raoul.duke]

OK, fair enough. Should I assume the prop valve is still good or should that go also?

[truckdude239]

should be fine you can replace it if you want

[sdmahr]

I got a lifetime warranted rebuilt master cylinder for mine at Advance Auto for less than $16.00 ! ! ! ! You cannot even buy a repair kit for that kind of money ! ! If it ever gives me any trouble, I'll exchange it for a different one.....for LIFE ! The one I got looks brand new and works great.

You have to "Bench Bleed" the master cylinder and then install. Basically this means you get the trapped air out of the master cylinder before you install it. In your situation, you will need to bleed the entire system at each wheel and then track down your leak. (my guess is you have a leaky rear wheel cylinder. Watch the back of the rear wheels when you get your new Master Clylinder installed and you'll see which one pretty quickly) Fix the leak and you will bleed again. I use a vacuum hand pump and bleed kit rather than try to mess with the ole'-two-person open and close bleeder screw routine. One of these days I'll make a small pressure bleeder but thats another story !

You CAN do brake work....its not that tuff'. If you have any questions as you move along there are plenty of people here who can answer your questions / provide pics, etc.

Welcome and good luck !

[truckdude239]

Originally Posted by sdmahr

(my guess is you have a leaky rear wheel cylinder. Watch the back of the rear wheels when you get your new Master Clylinder installed and you'll see which one pretty quickly)

!

he said "the front reservoir was overflowing but the back one is bone freaking dry. I assume this is not normal.......no leaks- should I just fill the backside and bleed or is there something else going on?"

this is an internal leak of the mc which will cause the brakes to go out but i would inspect the whole system and replace the parts you need

[raoul.duke]

10-4. Will replace the MC first thing Saturday morning....can't stand to have her sitting in the garage till then, but....

Will let ya'll know how it goes- thanks for the help so far...

[raoul.duke]

Got the MC replaced Saturday afternoon and the brakes bled.....brake light went out and everything. She was stopping so good that I hauled out to Rosenberg for a crawfish boil.......and about 25 beers....

[HUEVUDO]

I can tell you a retarded brake story. I went to the local brake place and asked for an estimate on my brakes on my 67 all the way around new shoes, springs, and wheel cyclinders. The price was insulting way too high , so me and my bud bought the stuff which was 5 X less than my quote and went to town. Jacked all four up about twenty five inches up 6 ton jacks stands. Did the rear , then looked at the front side compared to the new ones and decided they had plenty of meat on them and returned the new ones back to the store. One monthe later , call me squeaky Mcdieaky, the front need replacing like right NOW. Lesson number # 1,582 Learned. When you have it all broken apart and have the new **** right there stick it in, stick it in ..