Stuck brakes

I had been having a problem with my front brakes sticking intermittently for the past few weeks. Yesterday I replaced my calipers, pads, and rotors, hoping that would solve the problem. The calipers were old as balls, and the pistons were bumpy and rusty. After replacing all of the brake components, I drove a few miles, and thought the problem was solved.

Today i was out on a ride, and about 3 miles from home, the brakes started sticking again, to the point where I couldn't get over 20 without redlining it in 2nd gear. The front left brake was smoking hot when I got home.

What could the problem be?

The master cylinder could be acting up. The lines could be clogged. Did you bleed the system when you changed the calipers? If you did, did you include the rear brakes?

I did bleed the system, but just the front, as per my hanyes manual. The master cylinder is old and rusty looking, but why would it cause just one brake to stick?

You need to bleed all 4. Start with the farthest from the master cylinder, and work your way to the closest. So Pass. Rear, Driver Rear, Pass. Front, Driver Front. Completely bleed it until you get clear fluid and no air in the lines.

Bleeding isn't going to help his problem. Master cylinder or proportioning valve is sticking.

Originally Posted by Ram3500Dually

Bleeding isn't going to help his problem. Master cylinder or proportioning valve is sticking.

No it may not. But the job is only halfway done. Do it right for safty sake.

Air in the lines causes brake failure, not brakes staying on. He has bigger problems than bleeding

Yes I agree, there is a bigger problem. I never said to bleed the brakes to solve the problem. But like I said the job is halfway done. The rear fluid is now old and contaminated. Brake fluid builds up moisture which can cause poor braking performance due to loss of hydraulic pressure. And not to forget about rust which can eat away the lines, and pistons, or even make them stick due to junk preventing the pistons to return after a stop. Then when you try to stop you have no brakes, or less brakes, or stuck brakes!

He needs to fix the problem before he thinks about finishing the other job. If he has to change the master or the proportioning valve he would be wasting his time bleeding the brakes right now

A new master cylinder and bleeding all four wheels is were I would start. Most likely a seal in the MC is swollen up due to contaminated fluid causing to stay under pressure when the brakes are released.

I just spoke to my mechanic, he said it's likely a clogged brake line. I'm going to replace the rubber hoses this weekend and see if that fixes it. If it doesn't, I'll take it in to have the metal hoses replaced. Thanks for the advice.

I don't know about a clogged line. That would make the brakes not work more that stick on

as a mechanic i would say its the rubber lines seen it happen alot.

This whole poblem arises from not flushing brake fluid annually or bad shops that just compress caliper when doing a brake job, forcing the contaminated fluid in the caliper back all the way to the master cylinder and all points between.
When replacing pads all of this fluid should be expelled thru the bleeder and then the system flushed (bleed) until fresh fluid is all that comes out of the bleeder. (It also flushes any water/contaminates out of the system.)

I am thinking if the one side is getting hot, the other side is the problem, a bad hose that swells under presure is not getting the correct pressure to evenly provide pressure to both sides, although the proportioning valve is a thought, I believe that the valve just divides between front and back brakes.
So, my thought, brake line hose on other side...

Your correct that the prop valve is between the front and rear circuits.
Right now were all speculating until we hear back from Tim on whether changing hoses fixed his problem.

So here's the latest. The bolts that mount the hose assemblies up were terribly frozen. I soaked them in penetrating oil for 2 hours, and still couldn't budge it. I stripped the bolt, even though I was using the correct size wrench. Vice grips couldn't hold tight enough.

I'm going to take another crack at it on Thursday after I re-soak the bolts tonight, and if nothing works, I'll punk out and take it somewhere.

It sure does suck getting that far and being stopped by a stupid frozen bolt.