The Stovebolt Site Forums The Shop Area Engine Shop No brakes overnite ?

I have always been pretty proud of my brakes until this morning. As I was backing down the driveway, put my foot on the pedal and it went to the floor (luckily I was moving very slowly). Once I stopped I went forward, got out to see if there was any brake fluids on the ground or in the garage and nothing.

A few moments after I pumped the pedal, my brakes came back. What is the symptom doctor?
Maybe I need to check the fluids and bleed the lines ?

My beast has never done this to me before

For sure you need to at least check the fluid, are they still up now ??Fred

Tell us about your master cylinder. Is it new ? Old ? Rebuilt ? Single or Dual ?

First time in 10 years I looked in the old (probably originally single stage unit and found about 1/4" of muddy fluid. So I quickly filled it up but I'm sure I should probably bleed all lines this weekend. Don't see any leaks anywhere yet so can't say if I need a new master cyl.

Geez, maybe instead of just relying on mother nature to watch over my truck, I should get the fluids sometimes ????

The fluid did not evaporate. Try peeling back the dust covers on your wheel cylinders. I am betting they will be wet with fluid..

I was headed out to get some new tires for the truck, pulled to the end of the driveway (about 10% downhill grade), stopped, waited for traffic, took a left down the hill. Ten seconds later I had no brakes whatsoever. The stock master had spent years stewing in it's own muck and the piston seals had all but dissolved. When I put fresh fluid in the system all it did was wash the remnants out of the bore, about 10 pumps and it was just sloshing fluid around. I ended up buying a new M/C, lines, and sheetmetal.

At the very least, you should flush the system thoroughly and check for any leaks at the wheel cylinders/line blocks. Inspect the lines, and keep in mind that they tend to dissolve from the inside; replace if they are questionable. "Brick" the brake pedal and make sure it doesn't leak down, and make sure the parking brake will be there in a crisis.

"Safety forced." - Red Green

cmayna - aren't you are getting ready to do a paint job? I have just picked up all new wheel cylinders and a master cylinder and three new flex hoses and am waiting for Rugo to order his new stainless brake lines so we can get a qty discount and the total bill will be much less than it would cost to straighten an AD grill not to mention the rear end of just about any car.

If you are going to invest in your truck, brakes are about the best investment you can make. If your fluid is mucky looking, no doubt it has a lot of moisture in it and you have corrosion in your lines and cylinders.

Let's put it all in a nutshell. First is a complete inspection. Pull all the drums and check for leaky wheel cylinders, like 53 4 me said. I would bet that Ken is right, you have at least one leaker. Replace them all if you do. Put the drums back on and adjust the brakes. If you can, suck all of the fluid out of the master cylinder, you need to get all the gunk out of it. Fill it up from a fresh bottle and bleed each cylinder until clean fluid comes out. Don't forget to keep the m/c full. Once the bleeding is over, push the pedal down as hard as you can and hold it there for a minute or two. Usually takes both feet. IF the pedal suddenly drops, you probably have a bad m/c, if it goes down slowly it could be the m/c, a leaky line or wheel cylinder, or you didn't get all the air out of the system.

Tell me about it, brake inspection is very very important...I cant stress it enough.I lost my brakes on my way to work.Once I left the house the pedal felt fine, but once I got to the first stop light to make a left hand turn the pedal went soft.I didnt think much of it(big mistake).While driving down the road another red light, I hit the brakes and the pedal went all the way to the floor I kept pumping and nothing.Luckily a nice(new) pontiac grand am on the side of the road decided to stop for me.No real damage so, yeah always check your brakes on these nice ol' trucks of ours because brakes are useful once in a while

My experience is that if you replace the ENTIRE brake system on your old truck, it will be the last time you will touch for another 50 years or so.

DOT3 fluid is hydroscopic which means it will draw in moisture if it is exposed to it. Once you develop a leak, it's working in two directions; letting fluid out and moisture in. That in turn sets the old tin worm to work and that in turn starts rotting lines from the inside out. A brake line can be all painted up and look great and blow out an elbow at the first stop sign.

Replace the whole enchilada (wheel cylinders, master cylinder, lines) now if you do anything and you'll never have to deal with brakes again in all likelihood. Shoes can wait if they are ok.

Cmayna: Everybody is correct, especially Ken! You have a moisture problem. Not Good!! These trucks are great but they got to brake and brake now. Replacing whole system on my 59 don't care too much about myself but I do want to protect maws and the little ones. Money well spent. popcorn The Truth is Out There (JUST DO IT)

Though I was able to get the brakes up and "sort of" running by putting more fluid in, I totally agree regarding replacing the entire system including all lines. As Ken said "if your fluid looks mucky..." My fluid is as muckly lookin as a daiper with a real problem. There is definate moisture in the system.
Time to replace. It will be a couple weeks before I do it but will reply back when done.

Thanks to all for your advice.