Break problem need help

[JRDvorak]

About 2 months ago I did alot of front end work that includes new brakes and rotors. Everything as gone great. Last weekend I bought new breaks and rotors for the back and installed them that was about 500 miles ago. Now i am having front break issues. The front breaks are not releasing fully. It isnt happening all the time but when it does the rotors are hot and i get a break smell. Any idea what is wrong and what I need to do to fix it?

 

[Rustycowl69]

sticking pistons in the calipers? very remote possibility, I've only seen it once,
the flexible brake line to each front brake might be cracked internally allowing a rubber flap to act like a check valve when the fluid tries to flow back toward the mstr cyl. but more unikely if both front brakes are dragging. possibly abs sensors messed up.

 

[GoldDot]

Maybe a sticking caliper, maybe you didn't use new hardware, maybe you installed them improperly. Hard to say, but step 1 is to take them back apart to see what u can find.

 

[Rustycowl69]

if you waited too long to do the brake job, and the caliper pistons were way out of their bores, they can **** in their bores, allowing moisture to get past the seals and marr the bores surface finish. After you push the Pistons back in they can stick in the bores or **** again. It's probably going to mean new or rebuilt calipers.

 

[Rustycowl69]

If you happen to have the phenolic pistons, ask about rebuilt calipers with steel pistons. There are a lot of different theories, but for a lot of people the phenolic pistons seem problematic.

 

[xb1230]

If you happen to have the phenolic pistons, ask about rebuilt calipers with steel pistons. There are a lot of different theories, but for a lot of people the phenolic pistons seem problematic.

I do agree that the Phenolic piston can be problematic, especially if you haul and the brakes get very hot. However, from a DIY perspective, they represent a saving opportunity... Here is why:

The main reason it is not worth rebuilding a caliper is the piston may have rust pitting on the surface breaking the seal or making it impossible to make a proper seal. The remanufacturers will replace the piston after cleaning the rest of the caliper change the seals, rings and hardware and put everything back togeter.

With a phenolic piston, it doesn't get pitted from rust. But it does get rust particle sticking to it. Remove the caliper, clean the piston, and you can use a very fine sandpaper (600 grit and above) to smooth out the outer surface of the pistons (2 on the front calipers). Put new seals and rings and reassemble using brake fluid on the seals's surface to prevent assembly damage.

Silicone paste or brake lube on the guide pins and anti-seize on the pad slides.

Check for any bulging in the hoses, and replace if you see any cracks, or signs of wear.

I have done this to both my rear calipers and they work like brand new out of the box and it cost me a fraction of the replacement price.

I could not have done that with steel piston.

To get the piston out of the caliper, leave one brake pad in the caliper against the braces opposite to the piston. With a air hose/gun put some air pressure in the caliper and the piston should slowly come out. If doesn't you can use a grease gun to grease force the piston. The grease will offer more pressure without risk of damaging the caliper. If you have to use the grease method, make sure to thoroughly clean the assembly before putting back together to prevent brake fluid contamination.

Hope this helps