Brake Caliper Not Releasing

[TennesseeWrangler]

Ok, so as the title says, my driver side brake caliper is not releasing.

Let me give you guys the back story on this. I bought a 1997 zj 4x4 a week ago last friday. drove 2 hours to pick it up and drove it 2 hours home. EVERYTHING WAS FINE. It had some squeaking going on, figured no big deal, i can handle this.

So i lifted the front end and spun the wheels one at a time. they both made the squeaking noise. so i assumed the bearings were bad in the hubs. WRONG. i got new hubs and got the front end disassembled to change them out. got one hub off and spun it in my hand.......no noise. turned out to be a u joint in front drive shaft, rookie mistake, oh well.

here is where the break caliper comes into play. i had it propped up on something so that i wouldn't stretch the brake line. cool, good idea. well it fell off at one point and smacked something and hung from the brake line.

i went and put everything back together and test drove it for a few miles. next thing i know, there is the smell of brakes and smoke coming from that brake assembly, the driver side. if i took my hand off the wheel, it would pull to the driver side. if i hit the brakes, it would pull to the passenger side. almost like it wasn't fully braking but not fully releasing either.

so i got it home and jacked it up, bled that caliper because i hadn't done it earlier. (i never even messed with the other side). brake kinda sorta released after spinning the wheel a few times. got in and turned it on and hit the brakes a few times as though i was driving it. tried to spin the wheel again, brake seems halfway locked again.

SO I NEED HELP GUYS!! WHATS GOING ON HERE!?!!?!?!
DO I NEED A NEW CALIPER OR DOES IT GO DEEPER THAN THAT?!

 

[Buddha.]

The rubber brakeline has collapsed not allowing the pressure to return from the caliper, my guess. I'd replace both sides, they go bad after a while. You could rebuild the calipers as well. Need some compressed air, a small chunk off wood, and some steel wool along with the kit.

 

[jscusmcvet]

You can also pick up a new caliper at any auto store, and the swap is easy. I just had to do both rears on my 2005 within the last several months. Don't sweat changing out the hubs, can't hurt with a vehicle that old.

John

 

[TennesseeWrangler]

thanks you guys.
my preacher is also a mechanic and he said the inner lining of the rubber brake line. but i cant accept just one opinion lol. so im glad you said the same thing. and i'll probably just replace both calipers. as for the hubs, i returned them to get the u joint and everything. but its not difficult to change them out in the future.

 

[Doctor W]

I've got a ZJ and can tell you .........

Before you go buying new calipers be aware that the front brakes on ZJ's (and same era XJ's and TJ's) can "freeze up" on their slides due to lack of lubrication on the caliper slides.....all you need do partially dismantle and clean it up with spray brake cleaner and maybe some bronze wool and re-lube with high-temp copper grease on the slides.

It'll pay you to check this out before spending money and work on new calipers. It's good practise to do this as yearly maintenance at least.

Of course, the piston CAN also seize inside the cylinder of the caliper, but lack of lube is very, very common problem.

 

[Jim K in PA]

If they are original, 14 year old parts, I would change the hoses and the calipers. Reman calipers are inexpensive. The hoses will probably be about the same price as the caliper. Reman caliper comes with new slider pins and seals.

 

[TennesseeWrangler]

ok so i dismantled everything and the piston of the caliper was indeed seized up. so i went ahead and bought new calipers and hoses for both sides. i replaced everything today and bled both front lines because those are the ones i replaced. the Master Cylinder ended up being pretty low. like way below the add mark. but it still had visible fluid in it.

so i got everything bled and put back together and now i have no brake pressure. i dont understand why.

can ya'll suggest anything?!

 

[DaveNay]

can ya'll suggest anything?!

Bleed 'em again.

 

[TennesseeWrangler]

bought a bleeder kit with the little hose and bottle to attach to the bleeder screw. calipers were on right. hooked it up and had the wife help me. she'd press and hold the pedal and i'd loosen the screw and let it bleed. then i'd tighten it again and then tell her to release. then repeat the process until it was done. so now all is well!!

 

[DaveNay]

bought a bleeder kit with the little hose and bottle to attach to the bleeder screw. calipers were on right. hooked it up and had the wife help me. she'd press and hold the pedal and i'd loosen the screw and let it bleed. then i'd tighten it again and then tell her to release. then repeat the process until it was done. so now all is well!!

:Mechanic::jumping::beer:

 

[ex m38a1er]

I've got a ZJ and can tell you .........

Before you go buying new calipers be aware that the front brakes on ZJ's (and same era XJ's and TJ's) can "freeze up" on their slides due to lack of lubrication on the caliper slides.....all you need do partially dismantle and clean it up with spray brake cleaner and maybe some bronze wool and re-lube with high-temp copper grease on the slides.

It'll pay you to check this out before spending money and work on new calipers. It's good practise to do this as yearly maintenance at least.

Of course, the piston CAN also seize inside the cylinder of the caliper, but lack of lube is very, very common problem.

Good for the OP!

Thank you Doctor!
I own a Tj and my front right brake is not being released as it should...
I can tell cause it pulls to the right when braking and sometimes whistles....It also smells...
I changed both front brake lines and the piston of the right calliper,but still.....
I'll try to do what you said....


Did not mean hijack but since there was a relative thread...

 

[KaiserJeep]

The thing about single piston calipers is that they MUST be free to slide back and forth. After a brake application, the pads will be in contact with the rotor on each side. The small runout of the brake rotor (just a few ten-thousanths) will retract them far enough, as long as no air is in the system. Each time you do a brake job, check the caliper mounting bracket for burrs, and file them off if present. Also buy new slider bolt kits (bolts/pins, rubber boots, and grease) for each brake job, they are cheap. Finally apply just a tiny dab of copper grease on each caliper where the pads contact the caliper.

When bleeding the brakes, pump fresh fluid from the master cylinder to the individual brake screws. I use a glass jar and don't stop until I see fresh clear fluid in the jar from each wheel, because the brake fluid is hydroscopic, it absorbs water and holds it in suspension. But once the water reaches about 2% by volume, it can become steam when the brakes overheat (immediate and sudden brake fade in the mountains), and will start to slowly corrode brake cylinders, pistons, and steel brake lines invisibly from the inside.

The fluid change is incredibly important if you have ABS brakes, those parts are very costly. If you allow the contaminated fluid to begin the corrosion of the steel parts, you can end up spending more on your ABS brakes then a new engine costs.

Brake fluid condition can be told by color:

1) New and safely dry brake fluid is clear or possibly has a very slight amber tint, depending upon type and brand.

2) Dark amber fluid that you cannot see through indicates that it is saturated with water and corrosion is beginning. Service the brakes immediately with new (or turned) pads, rotors, and a complete fluid change. The amber color is tiny rust particles from the water in the saturated fluid coming into contact with steel surfaces.

3) Black fluid indicates severely contaminated fluid where larger rust particles have abrasively worn the rubber seals in the entire brake system. Replace or rebuild the master cylinder, proportioning valves, calipers on disk brakes, and cylinders on drum brakes. Remove and replace all the rubber brake hoses and hard steel lines. If you have ABS parts, replace all those that contain fluid. This will be at least a $2000 brake job.

Considering how cheap fresh brake fluid is, it should be replaced about every three years in dry climates, and annually when you drive your Jeep through streams and immerse the brakes in water. With clean dry brake fluid, you should never need the expensive brake job.