OK guys. I have a problem that has me completely stumped. My problem is that I cannot get any pedal resistance on my new brake system. All components are new or lightly used. I've attached two photos of the brake assembly for your benefit.
Here is some background:
I have GM disk brakes in front and GM drum brakes in the rear. I have an 8" GM power booster off a mid-size car like a Lumina. I have a reman GM dual master cylinder (1" bore) intended for a 1/2 ton GM pickup. Because the master cylinder is under the floor and lower than all the brake cylinders, I have included a 2 lb. residual valve in the front brake line inches away from the master cylinder and a 10 lb. residual valve in the rear line with a proportional valve between the master cylinder and the 10 lb. residual valve. I have a new vacuum line from the booster to the rear vacuum connection on the 4 brl. carb. and it is pulling good vacuum. I have bled the lines starting from the farthest wheel and worked to the closest wheel, doing the front first and then the rear. I have bled them each twice searching for any air. No air was revealed on the second bleed. The master was prepared on the bench exactly according to mfg. instructions and had only about 1/8" travel when operated by hand before it was installed on the car. There are no leaks anywhere. The rear drum brakes have been adjusted and rechecked twice for minimal clearance from the drums. I have 6 1/2" of pedal travel from full rest to the floor. The pedal ratio is 6 to 1. I'm using fresh DOT 3 brake fluid.
I cannot get a firm pedal, with or without the booster assist and I cannot figure out why. What am I missing or doing wrong?
Here is some background:
I have GM disk brakes in front and GM drum brakes in the rear. I have an 8" GM power booster off a mid-size car like a Lumina. I have a reman GM dual master cylinder (1" bore) intended for a 1/2 ton GM pickup. Because the master cylinder is under the floor and lower than all the brake cylinders, I have included a 2 lb. residual valve in the front brake line inches away from the master cylinder and a 10 lb. residual valve in the rear line with a proportional valve between the master cylinder and the 10 lb. residual valve. I have a new vacuum line from the booster to the rear vacuum connection on the 4 brl. carb. and it is pulling good vacuum. I have bled the lines starting from the farthest wheel and worked to the closest wheel, doing the front first and then the rear. I have bled them each twice searching for any air. No air was revealed on the second bleed. The master was prepared on the bench exactly according to mfg. instructions and had only about 1/8" travel when operated by hand before it was installed on the car. There are no leaks anywhere. The rear drum brakes have been adjusted and rechecked twice for minimal clearance from the drums. I have 6 1/2" of pedal travel from full rest to the floor. The pedal ratio is 6 to 1. I'm using fresh DOT 3 brake fluid.
I cannot get a firm pedal, with or without the booster assist and I cannot figure out why. What am I missing or doing wrong?