‘95 seized caliper mystery

What can make only one side seize? Even with new caliper…
Longer version, I have a ‘95 that I did brake pads on, the driver’s side caliper had one piston that was a real bear to get compressed. I went ahead and put everything back together but there was definitely some braking and driving vibration that I didn’t have before. I got back to my house and smelled hot brake smell from that wheel and assume a partially seized caliper so I went ahead and decided to put a new caliper on. Installed caliper, bled thoroughly till getting nice clean brake fluid through, and went for a test drive. About 5 miles of 40-45 mph driving and a few stops vibration and hot brake smell back. I was able to get home quickly and immediately jacked the front up. The driver’s wheel won’t turn and strong hot brake smell. Passenger side is just fine. Got my temp gun out and the rotor on the driver’s side just red hi, which I think is above 300 degrees, the rotor on the passenger side was about 160 so I fully feel the caliper is holding pressure for some reason. What do I dig into now? Thanks all!

 

Did you lubricate the pins and are they straight? Are you sure the caliper is installed properly? Also, you may have just gotten a bad caliper. Found this for troubleshooting: https://enginerevup.com/brake-calip...t,Caliper ... 6 6. Brake Fluid Contamination

 

I have, once, on a 30 year old vehicle seen a brake line (Rubber hose) fail in such a way that internally the damage was like a one way valve, causing pressure not to bleed instantly after brake applied pressure was released. The caliper was initially rebuilt in an attempt to correct the problem.
If all other items check out fine, It may be something to look at.
Keep us update on what you find.

 

Check the brake proportioning valve, if it has one, and also check the passenger rear brakes.

 

Thanks guys, I have determined it’s likely the flex line failing internally acting like a check valve. They are cheap so I am going to go ahead and do that next. It does have the proportioning valve still, but the rear brakes are not acting up so I am going to skip investigating that for now.

 

Well, replaced the flex hose and it is still doing it. I was able to take the old hose and hold it straight and could see straight through it.

What do I go to next? Seems like if it were something in the master cylinder the other brakes would also be affected? Anything to do with the abs actuator that could possible be holding this pressure?!

 

For some closure on this post, the previous owner put a new brake booster in and didn’t quite adjust it properly. The pushrod was slightly compressing the master cylinder holding a little pressure. Adjusted that, bled everything really thoroughly and seems to be happy now!

 

Great catch!