I have a '67 PA-28-140/160. My brakes keep getting air in the line, and I have no idea where it is coming from. I don't see any fluid leaking out, but the air seems to be getting in towards the caliper piston blocks based on where the bubbles are when I bleed the brakes.
During the prior annual, I had the brake pads replaced and the A/P indicated that the blocks were in pretty bad shape (lots of pitting). I was wondering if that pitting could be causing the air to get in, or is there somewhere else I should be looking for the air to be getting into the system.
After bleeding the brakes, they do hold pressure for some time, but keep getting soft after a few hours of operation. They only go soft when operated, and not while just sitting.
Any advice would be great. Thanks.
