brakes lockup

[dirty white boy]

I have never seen a rubber brake hose collapse. It has always been where it is crimped together at the end to the metal. Rust forms under it, squeezing the hose shut.

the ones ive seen,...rubber com lose on inside,..an plug line up....line look fine on outside!

[Egoracing]

YES true BUT synthetic is much worse at absorbing or attractiong the water from what I remember.

I havent read about it in years but I remember when the synth first came out everyone was getting soft pedals from it within a night or two.

You ever see someone go to the old "racing" synthetic fluid that would NOT mix with regular fluid. They would mix and it looked like burnt jello.

[gadirtracer]

You ever see someone go to the old "racing" synthetic fluid that would NOT mix with regular fluid. They would mix and it looked like burnt jello.

Ego, do you cook your Jello?

DOT 3 or 4 store brand fluid will work on a street stock, just keep the system bleed and the fluid fresh. After every race or two, I'll bleed the calipers to get the old heat soaked fluid out of the calipers and top it back off with fresh fluid.
When I buy brake fluid, I get the small bottles, to minimize the times the lid is removed allowing moisture in.

[gadirtracer]

jarvis, are you using an inline residual valve? If so, which one? Why?
If you have a master cylinder designed for rear drums and you now have disks out back, that's you issue. Some stock masters have the residual valve built in them. Drums require more pressure to operate and the m.c. is holding a set amount of pressure there when you are off the brakes, the components heat up and expand and now your brakes are locked up.

[gadirtracer]

Read this......

http://www.thebrakeman.com/valvetechi

[stock car driver]

You ever see someone go to the old "racing" synthetic fluid that would NOT mix with regular fluid. They would mix and it looked like burnt jello.

No, I have a fairly small group of racers that I travel with now and then and run special events and they arent into experimentation in the least.

Dot 4 is better for heat than 3 it has a higher boiling point so I suggest running dot 4.

[doitinthedirt2]

brakes

what proportioning valve are you using ? if it is one for rear drum brakes it will lock up your calipers. it needs to be one for disc brakes. they only have a 2 pound residual pressure compared to the 10 pounds that a drum brke prop valve applies. hope this helps. if it is an aftermarket vale it should have a big 2 for drum and a 4 for disc brake.

[jarvis]

not runnin a valve and I was told the calipers for the rear are off the front of a 84 grand prix he said it was the same set up he used and hasnt had any problems but heading to the track in a couple of hours see how it goes will let you know

[jarvis]

well the car was better tonite but it still wasnt rite was not burning hot dogs but the brakes were sticken Guys I have change everything what do I need to run

[gadirtracer]

What master cylinder are you using?

[jarvis]

Its off of a 84 grand prix i think. To the point of putting the drums back on as bad as i hate to. Tore the car apart today left rear was the worst the rotor was broke and they are off a corvette

[jarvis]

What is the best stock mount dual res master cylinder to get and I have a ford 9in with 4.75 bolt pat for rotors

[racerkrp1]

RE

I use a mid 1960's corvette Master cylinder for manual 4 wheel disc. Works fine for me.. You can get them for about 30 bucks...

[gadirtracer]

Either your master cylinder push rod is not returning the piston all the way back or you have a master for rear drum brakes with a residual valve in the port. If you are still utilizing the factory brake lines, there maybe one on the frame rail somewhere "holding" 10 psi of brake pressure on the calipers. (As you said you removed the combination valve already.)
I would get a m.c. for something that came with 4 wheel disc brakes and carefully go over all lines under the car.
Only time a residual valve is needed is if the m.c. is lower than the calipers/wheel cylinders allowing the fluid to flow back to the m.c.
Let us know what you find.

[jarvis]

I ran all new lines from the master and I was told from the parts store the cylinder is from a 1968 truck and Im guessing it was disk all the way around since he said he is running the same set up but I did see my guy ran the lines on the master Front brake to front inlet on the master should the front be ran from the back side