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MG MGB Technical - How to Wind back calipers?

Iam changing the brake discs and pads on my 1970 MGB GT which I bought from an elder gentlemen whom had it dry stored after restoration back in 1994, thats 11years the calipers have been stuck on thier present position!!!!.
Does anyone know of any 'tricks' to get the calipers to wind back free'er than they are, cause they wont budge!!

Thanks
Mike S
MikeS

Mike

Most likely you have some corrosion that has caused the pistons to stick. You need, at the least, to pull the calipers off (are they stuck to the rotor?) and either rebuild or replace them. Check the archives for various techniques for removing stuck caliper pistions. You can use compressed air but there is a significant danger with the pistons coming out like shot out of a canon. An alternative is to fit a grease fitting to the caliper and use a grease gun to force then out. Check the archives for lots of guidance and ideas on this topic.

HTH

Larry
Larry Hallanger

Hi Mike, If you have tried to free them with wd40 or similar and they still won't move, release the bleed nipple and try again (the hoses could be perished inside and act like a one way valve)if this still doesn't work press the pedal (after tightening the nipple) to see if the piston moves out. If they are still tight your best bet is to by some new/recon calipers as even if you get them free they will probably sieze again Terry
Terry Drinkwater

MikeS, I usually use a large C-clamp to press the piston back in. Crack the bleeder open, flip over a brake pad to cover the piston face, and secure the clamp over the caliper and pad. That should get it free.
Jeff Schlemmer

I would push them out a bit (clamp one and let the other move. Clean them up and then push back with a cramp.I have a small portable vise that fits perfectly and you just twirl the handle until the piston is home . Watch you dont push fluid out of the master cylinder reservoir .Yuo should be changing the fluid , unless its silicon anyway.
S Best

Thanks everyone for the advice, I'll have another crack today, to answer a few questions you have all asked, I have soaked them in WD40 overnight and i will try again this morning with a c clamp, although i didnt relase the bleed nipple!
I will be replacing the 11year old brake fluid definatly!!.
Thanks again
Mike S
MikeS

Mike,
You probably realise this but do reseal them if you've used WD40 on them, whatever the outcome, as it will damage the rubber.
Rich
Rich

This thread was discussed between 04/04/2005 and 05/04/2005

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