RustX7

When I recently replaced my rear calipers, the bolts
holding them on were practically welded into place.
Heating and penetrants were of no use. I eventually
gave up and cut the calipers off with a sawzall (I had
a few cores lying around so I didn't care.) The stuck
bolts, it turned out, were not stuck on the threaded
part, but on the smooth part, where something that
honestly looked like concrete had formed. I have no
idea what this stuff was but it was some kind of
corrosion, maybe from dissimilar metals coming into
contact? I don't know.

Anyhow, my right front caliper just froze on me so
it's time to do those, and these bolts don't want to
budge either. I've been soaking them in PB blaster for
three days now. Today they didn't respond at all to my
impact gun.

If it's that same corrosion stuff holding my fronts
on, is there anything I can dump on them to try to
dissolve it? Or some other trick?

Icemark

sounds like salt build up, just replace the calipers as you don;t want to worry about the caliper sticking instead of sliding.

RX_AV8TR

1/2 inch wrench, 6 face socket and a 3 foot pipe, if the threads are not frozen not even Marine Tex will hold them in....or they will break.

RustX7

Mark --- yeah that's what I'm trying to do if I can get these bolts out

RX_AV8TR... I will try. I'm wary, though, since snapped the heads off some of the rears trying that. But I believe those were 15mm bolts and these are 17's.... hopefully they'll hold...

RETed

Impact gun???!!


-Ted

tekgraphx

I recently had the same problem with the bolts on the front calipers of my 88 vert. I was draining my air compressor with the impact gun to no avail. In reading some of the older posts on the same topic someone observed that if you have an impact gun rated at 100 ft/lbs that no matter how much air you put through it, you will only get 100 ft/lbs out of it.

I bought an "Earthquake" gun that is rated at 625 ft/lbs and was able to break them free (it did drain my compressor twice before they gave up).

Good luck with them.

digitalsolo

iTrader: (2)

I took a torch and a hammer to mine before they gave up. Beating on them while they were red hot for a few seconds knocked a lot of the crap loose, and they came right out.

My rears I broke the heads off of, and had to have drilled out. I loaded all the new ones up with anti-seize before reassembly, though my car is a garage queen now anyway.

doridori-rx7

iTrader: (3)

Not using enough heat on the iron spindle, you need to use a oxy torch to get it red hot around the bolt hole.. it's that easy

RoadRaceJosh

Don't forget to grease up the pin before you put the new caliper on! There is special silicone brake grease just for this very application. Also make sure the little rubber boot is intact to kep as much of the weather out as possible. I got lucky when I did my rear brakes 7 days ago. The hardest part for me was removing the screws holding the rotor to the hub. After beating on the screws with a big punch and hammer they came out. The screws went back in with anti-seize as did the inside diameter of the rotor.