Hi, I've got a caliper that works fine, but the upper bolt that it's supposed to slide on is rusted frozen. I can rotate the caliper bracket up and down with a little effort, but definitely cannot slide the caliper bracket in and out as it's supposed to. I've tried PB penetrant fluid, a couple whacks with a mallet, and still nothing seems to break the bolt loose. I'm nervous to try heating it up, as there's a lot of flammables in that area. Any suggestions?? By the way, it's a 3.0L '89 Dodge Raider with 320,000 on it.

Thanks,
Jeff

If it's that badly corroded, I would consider replacing the entire caliper. The caliper needs to slide. If it can't, you will wear the rotor unequally. If you still have the original brake flex lines, you can replace them at the same time.

Are you talking about the mounting bolts or slide pins? If it's a slide pin and you can get the caliper off I would just buy a rebuilt caliper as MarkG suggested. You may be able to leave the caliper mounted and use a wrench to turn out the pin from the back. That may at least loosen it. But I have always found the pins to be bolted in pretty tight so use a big wrench. If you can remove the rubber dust seal from the pin you may be able to apply heat but using only a porpane torch will take some time and transfer heat to unwanted areas, like the brake fluid. I would stay away from heat.

Don't we need Big Blue to say, "You're a wreckless criminal who endangers the lives of our children!!!" at this point? <img src="/forums/images/graemlins/lol.gif" alt="" />

I learned from him. How 'bout you? Betcha did. One cold one wagered? I'll take the wish for the deed....

Get the bad pin out somehow. The caliper MUST be able to slide in and out VERY freely, or the brake will drag, eating pads/rotors, overheating metal and bearing grease and brake fluid and seals and pads and rotors, and causing grossly uneven pad wear. The ONLY force to move the pads out of contact with the rotor after brake application is (1) the torque on the caliper piston square section oring, and (2) the "stubbing the toe" effect of the leading edge of the pad on the rotor surface as the pad pressure is released that boosts the force of the oring torque. Any binding of the caliper on the slide bolts/pins is enough to defeat these fairly weak forces. I'd say yours is terminally bound.

I think there's a "dust cover" cap over the slide pin bore on the back side of the caliper that you can twist off with pliers. Mine had a hole in the middle of the cap. I'd pry the caliper in the off direction, and whack a drift into the slide pin bore at the same time to break it loose. I'd soak the hole in PB Blaster first. If that fails, I'd heat the caliper and chill the pin, and repeat.

I also seem to recall some kind of hex for a wrench on the pin itself. Inner end, maybe, smaller than the pin diameter.

Wow, talk about a quote taken out of context. <img src="/forums/images/graemlins/lol.gif" alt="" />



Personally, I think the board has been just fine without the presence of his condescending attitude. Although, you're right - from Kary I learned how NOT to act as a mature individual, especially as an educator.

That bolt is threaded into the caliper bracket. It is threaded through a chrome plated steel sleeve that the caliper slides on.

You should be able to work the caliper off the slide, providing the head of the bolt is smaller that the hole in the caliper, it should be. It might take a bit of force.

That will leave you with a bolt stuck in the caliper bracket. At that point you can use some heat on it.

At the very least you need a seal kit for the caliper to get the seals for the slide. You also need a bolt and a new pin. A rebuilt caliper is not a bad idea.

My experiance is that bolt almost always likes to seize in the caliper bracket. I like using some anti sieze on it. Also the pin in the caliper tends to get contaminated with water and the grease fails.

A good yearly maintenance is to relube the slide pins. If you get into water re-lubing them is a must. Permatex makes a synthetic lube for the pins and the factory caliper kits comes with a high quality grease as well. Personally I think the factory stuff is the best.

Kevin

Oh geez. You just reminded me of more work I need to do after my last stuck at the badlands.

Any way I believe you can slide the caliper off with that bolt in place. That will realy give you some more working room to try to get it out. If you do decide to replace the caliper get the loaded calipers from Napa.

Did mine 2 weeks ago and yea mine was frozen as well. All I can say is use a BFH and PB Blaster in mass amounts.