Over the last several months I have replaced the rear spring on my '67 L79, installed new front and rear wheel bearings and seals and installed four new shocks. I found a leak in one of the brake calipers which prompted me to repair not only that caliper but the other three as well so that they all had new seals.
I ran fresh fluid through the system until it was clear and all of the old fluid was out. There was already silicone fluid in the system so I flushed it with new DOT 5 fluid. I installed new brake pads on all four wheels since the set from the leaky caliper was soaked with brake fluid. I followed the recommendations in the service manual for pressure bleeding the manual disc brakes at between 10 and 20 psi. There are no air bubbles coming out when the bleeders on the calipers are cracked open yet my brake pedal is spongy and the car barely stops even though driven at low (25 mph) speed.
The brake pedal in my '66, in comparison, is like a rock when the brake is applied. That system is a single reservoir master cylinder whereal the '67 is a dual reservoir. The only thing that was done differently is that I installed Bendix ceramic disc brake pads because the parts suppliers in my area do not carry the semi-metallic pads and the ceramics were in stock. The brake pedal in the '67 will go almost all the way to the floor with only moderate effort when the car is parked and not running. Could there still be air trapped in the system somewhere or is it possible that the spongy pedal is coming from the ceramic pads?
This is a manual brake car and there are absolutely no air leaks from the master cylinder or any of the calipers while under pressure. The brakes in the car prior to rebuilding the calipers were as rock hard as those in my '66 when applied. All of the pistons moved freely in the caliper after they were rebuilt. I bled the system again today just to be sure I didn't miss any air-there was none coming out when the bleeders were opened. I cannot think of anything else to try so if any of the members have any suggestions I would greatly appreciate your input. Thank you.
Joseph Evans 45420
I ran fresh fluid through the system until it was clear and all of the old fluid was out. There was already silicone fluid in the system so I flushed it with new DOT 5 fluid. I installed new brake pads on all four wheels since the set from the leaky caliper was soaked with brake fluid. I followed the recommendations in the service manual for pressure bleeding the manual disc brakes at between 10 and 20 psi. There are no air bubbles coming out when the bleeders on the calipers are cracked open yet my brake pedal is spongy and the car barely stops even though driven at low (25 mph) speed.
The brake pedal in my '66, in comparison, is like a rock when the brake is applied. That system is a single reservoir master cylinder whereal the '67 is a dual reservoir. The only thing that was done differently is that I installed Bendix ceramic disc brake pads because the parts suppliers in my area do not carry the semi-metallic pads and the ceramics were in stock. The brake pedal in the '67 will go almost all the way to the floor with only moderate effort when the car is parked and not running. Could there still be air trapped in the system somewhere or is it possible that the spongy pedal is coming from the ceramic pads?
This is a manual brake car and there are absolutely no air leaks from the master cylinder or any of the calipers while under pressure. The brakes in the car prior to rebuilding the calipers were as rock hard as those in my '66 when applied. All of the pistons moved freely in the caliper after they were rebuilt. I bled the system again today just to be sure I didn't miss any air-there was none coming out when the bleeders were opened. I cannot think of anything else to try so if any of the members have any suggestions I would greatly appreciate your input. Thank you.
Joseph Evans 45420
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