Started in to do the brakes on the GTS this morning. PS caliper bolts came out just fine. Lower DS was a bit tight. Upper DS wouldn't budge. Broke two Craftsman 10mm Allen sockets.

Here's what I tried so far:

1. Penetrating oil
2. Heat
3. An impact driver
4. Welding the 10mm piece from one of the Craftsman drivers into the bolt then using a 10mm impact socket with breaker bar: sheared through the 10mm Allen piece flush with the top of the bolt.

I am now trying to drill/grind the head off the bolt, but it's slow going. Any other suggestions?

Thanks,
Paul

 

I had the same exact problem and took it to SeanR. He had to drill the head out. Once done, the caliper slipped off and he backed the bolt out with vise grips if I remember correct. The PO had locktite the bolt it. Go figure.

Good luck.

 

Prior thread on this:

https://rennlist.com/forums/928-foru...llen-head.html

Sounds like the spiral extractor is no longer an option. Perhaps an external spiral extractor will work?

Make sure you get GTS caliper bolts (M12 x 80) as replacements, rather than M12 x 70's. (Ask me why I bring this up.....)

 

I had the same issue. I drilled off the head to get the caliper off. Once removed you have plenty to grad and can unscrew it easily. On mine, corrosion had glued the head of the caliper bolt to the caliper. Once the head was off it unscrewed by hand.

 

After a bunch of drilling, I did manage to get the head off and pull the caliper off. The remainder of the bolt came out quite easily at that point.

I did notice that the socket felt loose in the DS bolts, which had me worried they'd been overtorqued. In retrospect, the heat probably made things worse here, by expanding the caliper.

Now to see if I can find a suitable bolt locally...

 

Religiously apply antiseize upon reassembly.

My brake rotors had become galvanized to my front wheel hubs. No amount of torch heating could get the whole rotor hot enough. A five ton hydraulic pully puller wouldn't budge it, and the threaded holes were worthless.

Luckily, I had a set of new wheel bearings lying around.

I took off the wheel hubs and placed them one by one into a pottery kiln I have running with a PID controller to set and hold a temperature. I let them soak in 500F heat for about three hours each. All it took was a hammer to drive the hub out while the rotor rested on cement blocks. The kiln also came in handy to powder coat my front calipers as well.

 

Never weld Allen keys, they will never hold up after.

If this happens again, just drill the head out and slide caliper off.

 

As noted, I did have to drill the head off, and I had used the broken piece of an Allen socket, not a key. I would never expect to reuse a tool or bit that I had welded to something in a effort to remove it.

On the bolt: no local source. ACE had 12x1.75x80 in Allen or 12x1.5x80 in hex head, but no 12x1.5x80 Allen. I also checked Autoatlanta's parts breakdown, and they show mounting bolts coming in from the side - same size, but with washers. Mine come in from the top and don't have washers. Am I missing washers, or is the diagram incorrect for an early '93?

 

I forgot if you can get a vise grip on the head of the allen, but if you can, it might have come off with a wack of a hammer. glad you got it off!

Mk

 

The washers often stay inside the caliper bolt hole and fit so well in there they are very hard to see. HOWEVER, perhaps they are missing and that is why these bolts were so stuck. I would poke around inside the bolt hole and see if you can remove them. Perhaps someone can provide the depth of the hole w/o the washer so you can determine if they are there but just stuck. Since you had so much trouble, I would order the washers as well and replace them regardless.

 

SQLGuy the part you need is 90006726802 from Pelican
http://www.pelicanparts.com/cgi-bin/...0%31%32X%38%30

Destructo
How did you keep the powder on the calipers until you got them into the kiln?

 

I'm still going to check a couple of local sources tomorrow before mail ordering the bolt. Kind of bugs me that I'm stuck waiting for it... going to miss my A/C appointment because of this.

On the washers, they are there, inside the recesses in the calipers. The one got chewed up a bit while drilling out the bolt head, so I'll replace that as well. I'm hoping (although I think the odds are low) that my local dealer will have the bolts, or maybe that the import specialist shop might have them. I already know that NAPA and Fastenal do not.

 

Those bolts used to be on the single-use list. We all should have a few sets of old ones in the used/spares bin. Right?