seized Rear caliper bolts

[darbuck]

Hi lads decided to do rear arm bearings and fell at the first hurdle cant get rear caliper bolts on either side to budge completely seized any suggestions on getting them moving tried loads of G7 WD40 equivilant still nada.

[Hell Razor5543]

It would be useful to know what vehicle the calliper bolts are so attached to! If it is a C5, Citroen are known to thread-lock these bolts for their full length (so a blowtorch is needed).

[daviemck2006]

It would be useful to know what vehicle the calliper bolts are so attached to! If it is a C5, Citroen are known to thread-lock these bolts for their full length (so a blowtorch is needed).

And a blow torch knackers the calipers. It's a no win situation.

[darbuck]

Hi Lads i got them moving between using an impact wrench and breaker bar. Its going to be slow though massive amount of friction, hopefully i can get them out clean without damaging caliper it'll probably take a full day to get them out on both sides.

[BX]

Leave the callipers alone and disconnect the brake pipes. Clamp the flexible hoses so you don't loose all the fluid. The ABS can be tricky to bleed if you allow ALL the fluid to drain. If you really must undo the calipers the problem is the threadlock on the bolts. Heat well to soften it or you risk shearing off the bolt.

[Stewart(oily)]

That threadlock makes this job a pig, I remember taking a couple of sweaty hours to get them out, grease was always good enough for what appear to be identical items on the BX and Xantia. Keep digging.

[dnsey]

If you do remove the calipers, I suggest following Jim's excellent advice elsewhere on the forum:
Use a long extension, and apply moderate force steadily. As the bolt starts to move (they make a horrible creak!), allow time for the torque to unwind. Take it slowly, moving each bolt a little in turn, and don't try to 'snatch' at it - that's the easiest way to shear a bolt, which you really don't want!

[darbuck]

cheers lads have calipers off but bolts are still in calipers will try to remove completely and then copper grease them.

[daviemck2006]

If you get the bolts out of the calipers I would run a drill through the holes, I think it's 10 mm. Make sure there is no corrosion on the radius arm where the calipers bolt on, or on the face of the caliper, and copper grease those areas before refitting, or even make a gasket of very thin card to put between the caliper and radius arm. This will hopefully stop corrosion between the different metals happening, and help in the future when you next need the calipers off.

[darbuck]

hello chaps finally got the bolts out completely took two days of heat and impact gun ,breaker bar,and 2 and half cans of penetrating fluid absolute pig of a job.Im no stranger to grief when working on motors but this was ridiculous the main problem is not as most have said on here the loctite its actually oxidation inside the caliper the aluminium furs up around the bolt causing excessive friction going to drill out the threads on the arm and replace bolts with longer ones with lock nuts,lacquer the internal bolt bore on the caliper to try and stabilise the metal and then copper grease the whole bolt Im also going to paint up and copper grease the arm and caliper mating faces in the hope this will sove the oxidatiion issues as i cant go through this again its an absolute swine of a job.

[Lighty]

Oxy acetylene on the calipers , ingersol rand battery impact gun and ear defenders.
Two new calipers and jobs done in an hour

[Stewart(oily)]

The last C5 I did the caliper boltholes were flooded with red loctite or similar, possibly to exclude moisture, once I had wound the buggers out enough I transferred the whole caliper into the bench vice, blowtorch, assorted drifts, swearing, breaker bars, I did manage to re-use the bolts though, upon reassembly I liberally coated the bolts with my special mixture, grease, gear oil and the dregs of anything else the problem has not returned, that car has visqueen shims behind the caliper too.