I'm trying to remove right front caliper to change pads, and can't loosen caliper bolts. (One of them has a rounded head!) How does it come off?
Vehicle on hard flat surface. Two jack stands under the frame towards the front, front in the air, wheel chocks placed behind the rear wheels, parking brake on.
Wheels/tires removed, turn the wheels to the right when working on the right side, to the left when working on the left side.
Don safety glasses, and use a propane torch to heat the area on the brake caliper, where the brake caliper bolt goes into. Use caution as brake fluid is flammable. Keep the flame moving back, and forth, on the brake caliper area for the caliper bolt.
You'll have to experiment in this task. You won't be able to get this area cherry red, and you DON'T want to! Heat the area, tap on the area with a hammer, then try to remove the bolt. Keep doing this procedure until the bolt starts to move. See below for more detail.
You are heating cast iron, which expands more rapidly than the steel bolt. Now take a ball peen hammer, use the flat end, and TAP along the area you heated. DON'T beat on it, just medium taps.
Don leather gloves. Clamp a large pair of curved jaw Vise Grips on that bolt head. Clamp it as tight as you can. Tap the area once more with the hammer, then see if you can get the bolt to turn.
Viewing TOWARDS the brake caliper from the outside of your truck, the Vise Grips should go DOWN to the Right. The bolts have Right handed threads.
Turn to the right to tighten, to the left to loosen.
But you are on the opposite side.
Remember that the bolt head is on the backside of the caliper, therefore you have to orient the direction you need to turn it, to loosen it.
Once you remove a bolt, move it to a safe place to cool down. Do not quench it in water. You will anneal the bolt by doing this, thereby softening the bolt. This = No!
Suggest you use the proper thread tap, and clean the holes of the brake caliper, and the proper thread die to clean the threads of the bolt, before reinstalling.
Aug 02, 2009 |
1990 Mazda B-Series