My front passenger side brake started sticking a couple days ago and I noticed a squishy pedal to go along with it. I jacked the car up and had a look and i noticed the outside layer of the hose starting to tear. I had just ordered rear calipers so I went ahead and bought front ones too just to be sure. I just replaced the passenger side caliper (only one side bc I'm too mad and tired to finish right now lol) and the damned thing still sticks, only without the squishy pedal. Bearings, rotors, pads, and now a caliper were all replaced within the last 3k miles. The spindle nut isn't too tight, and the wheel spins freely without the caliper on. Every other brake on the car is fine aside from some ebrake issues.

I took my time installing the new hose and there is no kinks or bends. I lubed everything up on the new caliper, even the pad shims after I found out it was still sticking. No luck whatsoever, the piston gets stuck out but it is pretty easy to push back in with a clamp, it doesn't make sense! The pads and caliper move freely back and forth when the piston is compressed. I spun the driver side wheel, it went for a good 15-20 seconds. When I spin the passenger side it lasts about 5 seconds or less.

So after putting the wheel back on the pads are still dragging on the rotor but it rolls backwards very easily in my garage. Anyone have experience with this sort of thing? I'll update after driving it tomorrow.

It's an 84 gs.

***Edit after driving
The pedal went soft again, I'm not sure if it's from sitting overnight or what. I used the brakes some and there wasn't any signs showing the caliper sticking after a 15 minute drive. Ill be able to tell for sure when I drive to work. The old calipers got stuck after about 20 minutes of driving. I bled the caliper for 20 minutes last night so I don't think it's air making the pedal soft, but I could be wrong. No leaks anywhere.

 

Its air but finding it is the challenge. Might be the master cylinder leaking down. I would still
bet you need to do more bleeding. Also have the bleeder hose loop up above the caliper
and then down into the bottle. This way air will not suck back into the caliper while bleeding.

Spinning the wheel by hand should not last long, the bearings should be tight enough that it
doesn't really spin freely that much. This tells me the driver side is too loose actually. Probably
needs the same love.

Best practice is to replace the same items left and right. If one caliper and hose are bad the
other side will be soon.

 

I'll try bleeding again and tighten the spindle nut just a bit on both sides, since they are both free moving basically. Ill be replacing all 4 corners this weekend, this was just supposed to be an emergency fix.

 

t_g_farrell, Exactly what I was thinking when I read the original post.

A sticking caliper can also be caused by a faulty slide pin. Ensure your slide pins are lightly greased and that each caliper moves freely on the slide pin.

You generally want to bleed the brakes starting with the right rear, and then move to the left rear, but in the FB with rear drum brakes, there is only one bleeder for the rear and its on the right rear. Bleed that until you have a firm pedal and then move on to the right front and then the left front. The reason you have a soft pedal is that there is air in the lines somewhere. The pedal will never be rock hard but should not have a lot of travel. If you would like the correct travel I can look that up and post it. Remember that worn rear shoes will also contribute to pedal feel.

Check the area on the booster under the brake master cylinder. Ensure that the area is not wet with brake fluid and check for signs of peeling or bubbling paint on the booster. This indicates a leaking seal on the piston inside of the booster.

 

I should've said earlier but it has a disc brake rear end swap from a gsl. The pedal before all this happened was nice and firm but now it takes a couple inches before the brakes engage. I'll do the whole brake job this weekend along with a full bleed.

Oh yeah, when I finished bleeding the one caliper and closed the bleeder screw the pedal went to the floor and I had to pump it to regain pressure. Is that normal with bleeding?

 

You still have air in the system if the pedal went to the floor.

 

master cylinder

I've also seen cases where they cause the calipers to stick

 

I had the exact same problem on an identical setup. My 83 has a rear disc swap from the GSL also and last week ,with no warning signs, I completely lost brakes. The pedal had to be pressed down to the floor in order to get any kind of brake response! All hoses and lines were good,no visible leaks at the booster or master cylinder. After fiddling around for days I finally removed the master cylinder and lo and behold, the seals were swollen and ripped and the piston/plunger stuck.
Ordered a 'new' master cylinder and they sent the one listed in the catalog for the model year (drum brakes) so no pro portioning valve. On installation when brakes were applied it locked the calipers in the rear! Had to do a lot of forum searching and googling in order to get a diagram and instructions/advice on removal of springs and a couple other internal components of the master cylinder in order to get functionality of the rear calipers.
It was definitely a learning experience!

 

I'm hoping it's not the master so I'll bleed first. Thanks for the help guys.

 

It could be the master. If so its an easy replacement.

 

Remember that the Brake Master Cylinder can leak past the piston internally such that you won't see any leaking fluid (or down the inside of the firewall under the carpet). Pull the carpet back to be sure, but if it's sucking air in at the actuating rod attached to the brake pedal, you'll be constantly introducing air to the system and will never be able to bleed it properly.

From your description, that's what it sounds like to me - a bad Master Cylinder. Replace as a rebuilt (or new) part, as the piston rebuild kits don't last long in my experience. Good luck,

 

Still haven't had time to finish the brakes. But I've been daily driving it and haven't lost any more pressure. If I finally get to finish the job I'll go from there.