Can't Remove Caliper From Front Disc Brake Rotor

71convert · Sep 5, 2024

I have looked all over this site and have done a bunch of internet searches but I can't find a solution for my problem. I'm hoping someone on this site can point me in the right direction.

I replaced the front clip on my 71 Mustang and brought home the original left and right side of the front clip so I can strip off any usable parts. I am now in the process of removing the suspension and brakes so I can restore them. The issue I'm having is with the first, rusty front disc brake I'm trying to take off (see below). I removed all bolts from the caliper (at least I think I have) but the caliper will not release from the rotor. I have lubed the brake pads, all the caliper parts and even try to persuade it off with a mallet but it won't budge.

Can someone tell me what I may be doing wrong and can't get the caliper off? I am sure I am missing something as I can't imagine is should be this difficult to remove the caliper.

Thanks.

72conv · Sep 5, 2024

You must remove the caliper locating pins. They go in from the back side of the caliper. Here are some snapshots from the Ford shop manual.

71convert · Sep 5, 2024

Thanks 72conv. I included a picture of the rear of my caliper and I have already removed the caliper locating pins and the stabilizer bolts, unless I'm seeing something different. Are there any other bolts or clips I need to remove?

giantpune · Sep 5, 2024

Sometimes you need a pry bar. After you remove the bolts/pins, the caliper can be seized up on the rotor. Pry up at the edge. Do 1 side, then the other, then the first one, and wiggle it off like that.

Right about where this arrow is pointing.

And in some designs, the little springy clips that hold the pads in also kind of hold the caliper in place. You can disengage the tab on the pad from the springy clips.

71convert · Sep 5, 2024

Thanks @giantpune. I will give that a try.

Hemikiller · Sep 6, 2024

Yep, pry bar time. Sometimes you just need to choose violence.

MikeGriese · Sep 6, 2024

If you have a trash can, a hose and $12, you can put the whole wheel assembly in the trash can filled with a gallon of feed grade molasses and 9 gallons of water and wait a couple of days. The molasses solution will remove a lot of that rust.

Ron Tanzi · Sep 6, 2024

The piston is probably seized. So just what Hemikiller said: "choose violence". Or try explosives.

Ron

71convert · Sep 6, 2024

Thanks everyone for your advice. I think I may take up Mike's advice and soak the whole thing first to remove the rust. If that doesn't work then I will need to resort to violence.

ib4stangs · Sep 6, 2024

71convert said:
Can someone tell me what I may be doing wrong and can't get the caliper off? I am sure I am missing something as I can't imagine is should be this difficult to remove the caliper.

Might want to depress the caliper first and then pry it. A flat screwdriver in the top oval hole works too ...

rcadd1ct · Sep 6, 2024

It is possible that the caliper has rust behind the piston and it won’t release. If so it is probably trash maybe they will take it as a core.

Also the semi metallic brake pads can rust to the rotor. Try hitting the back of the caliper with a rubber faced dead blow hammer.

darb_123 · Sep 6, 2024

Looks to me like it is being held in place by the heavy rust. I have never heard of using molasses and water, but I would try it AFTER I try soaking it in white vinegar. I have used white vinegar to remove rust. I would try placing the assembly in a 5 gallon bucket. Submersing it in white vinegar for three to four days to loosen the rust. Then use a soft blow hammer in combination with prybars.

sevian87 · Sep 6, 2024

Time for new calipers and rotors instead

giantpune · Sep 6, 2024

darb_123 said:
Looks to me like it is being held in place by the heavy rust. I have never heard of using molasses and water, but I would try it AFTER I try soaking it in white vinegar. I have used white vinegar to remove rust. I would try placing the assembly in a 5 gallon bucket. Submersing it in white vinegar for three to four days to loosen the rust. Then use a soft blow hammer in combination with prybars.

Molasses works, but is slow. There are videos on the youtube of people soaking entire car bodies in molasses to strip rust. They take a couple weeks.

You can go to harbor freight or oreileys and buy a jug of evaporust to soak your parts in and they are rust free after 24 hours.

Otto · Sep 6, 2024

I would try the c clamp that was suggested. If the piston backs into the caliper, you should be able to get it off then tap the pads with a ball peen hammer. The shock of the hammer blows should break the pads loose.

CJ miller · Sep 6, 2024

I started with Vinegar for some of my rusty bit, then bought a bottle of Muriatic Acid.

351c1971 · Sep 7, 2024

NPD used to have stainless steel caliper pistons. Does anyone know if they are still available anywhere?

ib4stangs · Sep 7, 2024

Rick@NPD would....

California 72 · Sep 10, 2024

Evaporust? Saw that for the first time yesterday and now the comment here. Maybe there's something to it. Never really tried much other than naval jelly or elbow grease before. I'm actually media blasting now so, that might just be an option for things.
I got here late otherwise would have added that the best removal tool in the toolbox, a BFH, works great and you scrub off a little frustration at the same time. That is, until you miss swing and hit your fingers.

giantpune · Sep 10, 2024

California 72 said:
Evaporust? Saw that for the first time yesterday and now the comment here. Maybe there's something to it. Never really tried much other than naval jelly or elbow grease before. I'm actually media blasting now so, that might just be an option for things.
I got here late otherwise would have added that the best removal tool in the toolbox, a BFH, works great and you scrub off a little frustration at the same time. That is, until you miss swing and hit your fingers.

Its sold in harbor freight and oreiley auto parts stores here. It really is amazing stuff. I've had bolts that were rusted so bad they needed penetrating oil to get loose. Soak them in evaporust and they look brand new the next day. No scrubbing. I just wipe them off with blue paper towells.

The really crusty stuff like this takes a couple days and doesn't look brand new. But it does clean up to something you wouldn't feel bad reusing.

Can't Remove Caliper From Front Disc Brake Rotor

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