Thread: New build....brakes not cooperating

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I'm just finishing up a '65 Chevy II SS, tube chassis 18 month long build. I'm using all new brake components, including Strange discs all the way around, all new lines, residual valves front and rear, proportioning valve, and line lock, and new Strange master cylinder ( it was bench bled). I must be missing something, as I've bled this entire systerm over and over, and always come up with the same scenario. The first pedal pump goes to the floor, then the pedal is all the way up, and loses no firmness no matter how long you hold it. I've bled manually, and with a power bleeder....the same results. Brakes have always been a problem with me...I hate them. Thanks for any input.

It's probably silly, but the first thing that popped into my head was that the calipers, or a pair of calipers might be swapped side to side, putting the bleeders low on the caliper instead of at the top where the air collects. If you have a pair of bleeders sitting low you'll keep a pocket of air in those two calipers. Just a thought.

Oh good, another way to screw up. Hope I can remember that one.


Jack.

Strange 4 piston calipers.....they have bleeders top and bottom, so depending on how you fit them, you have a pair of bleeders for each caliper on top. Of course, you don't touch the bottom ones. Thanks for responding.

The first thing thatpopped into my head was the residual valves weren't holding. They are responsible for keeping the calipers full of fluid.

That first pump re-fills the calipers. Somehow you need to verify that they are holding back at least 2 pounds of fluid & pressure. Do you have any high pressure gauges and fittings? Test the pressure created by the pedal and then watch what it drops to.

Maybe just change the residual valves? Do they go bad? I suppose they could. Thanks.

somebody i know installed them backwards once ........

I called Strange to verify that when I first started having this problem. The OUT goes to the caliper side...is what they said.

I maybe confused, and that is often the case. However, I thought you used residual valves only when the master cylinder was lower than the calibers?

Originally Posted by 36 sedan

I maybe confused, and that is often the case. However, I thought you used residual valves only when the master cylinder was lower than the calibers?

Good catch, 36 sedan! 100% right, residual valves are not needed for a '65 Chevy II with firewall mounted master.

well actually---disc brakes aren't adjustable like drum brake shoes to keep peddle high and do use residual valves to maintain a closeness pad to disc no matter where the master cylinder is located
they just use a different pressure value


lots of master cylinders have the residual valves in the master

Originally Posted by jerry clayton

well actually---disc brakes aren't adjustable like drum brake shoes to keep peddle high and do use residual valves to maintain a closeness pad to disc no matter where the master cylinder is located
they just use a different pressure value. lots of master cylinders have the residual valves in the master

Well, these guys, for one, disagree - Typical Brake System Configurations They show NO residual valves for a firewall mounted master with discs all around.

Originally Posted by rspears

Good catch, 36 sedan! 100% right, residual valves are not needed for a '65 Chevy II with firewall mounted master.

it could if the master volume needs to be bigger most guys like the vett master for that

some sell shims under the brake pad to take up space less pedal travel when using a thinner rotor wilwood and other s do this go back and check the push rod that you not up on the rubber bumper on the stock pedal set up . i had to take bumper off and make the push rod longer

Maybe have an assistant eyeball the calipers during the first pump. Look for pads moving, they should have little discernable movement. It almost sounds as if the pads are popping back away from the discs, similar to shoes not properly adjusted to drums.