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Thread: Caliper rebuild

  
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    Caliper rebuild

    Is it possible to get replacement main/dust seals for front MK4 calipers as mine are getting a bit tight making the pistons a bit stiff?

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    no the Astra 'G' calipers are not like the older GM type calipers that could be serviced with seal and sliding sleeve kits. if you have a caliper fault then you will need a replacement caliper, they are around £65 exchange

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    Quote Originally Posted by steve1412 View Post
    no the Astra 'G' calipers are not like the older GM type calipers that could be serviced with seal and sliding sleeve kits. if you have a caliper fault then you will need a replacement caliper, they are around £65 exchange
    Since posting I've done a bit of surfing came up with this

    http://www.biggred.co.uk/vauxhallshop.html

    According to them you can buy a kit?

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    i stand by what i said, also if your pistons are stiff, this is because they are worn or seized and no replacement of dust seals will stop the piston from sticking. the caliper should be replaced as it cannot be stripped enough or safely rebuilt to cure this wear. but at the end of the day it is your money and it's up to you which route you choose to take mate

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    Quote Originally Posted by steve1412 View Post
    i stand by what i said, also if your pistons are stiff, this is because they are worn or seized and no replacement of dust seals will stop the piston from sticking.
    Thanks for your help but the main reason pistons get stiff/stick is because of main seal hardening. This is due to time and constant heating and cooling during use, by hardening they loose their elasticity and over grip the piston thus the system looses it's feel.

    Another reason is corrosion over time in the main seal rebate of the caliper body this pushes on the back of the seal over griping the piston again the system looses it feel in extreme cases the pistons will seize. In my experience stiff or seized pistons have nothing to do with the pistons at all.

    Piston ware is very rare as they don’t actually touch anything on their main working surfaces other than the seals. It is possible to get damage but this is normally caused by owners/garages ripping the dust seal by gripping the piston walls with tools trying to push them back during pad changes

    It should be possible to push them back by hand anymore then the seals are beginning to harden and need changing!!!!

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    Hi mate i opened a thread the other day very similar to this and asked the same questions. instead of buying new calipers do you reckon you could take calipers off the car and into a garage and they could do it for less than buying a new caliper? money is tight as the moment so looking to save the pennys any which possible.

    just qurious, did yours disks and pads bind thus making them over heat like mine did?

    Graham

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    Ive rebuilt a few sets of Astra G calipers - ive got a pair here if ur interested

    internally very good (20k use since rebuild - painted black but peeling)

    Also got 2 brand new calipers that only need new dust seals - attempted painting but gave up so need stripping and painting

    let me know if ur interested

    only suitable for 280/308mm discs

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    Quote Originally Posted by kingofkings View Post
    Hi mate i opened a thread the other day very similar to this and asked the same questions. instead of buying new calipers do you reckon you could take calipers off the car and into a garage and they could do it for less than buying a new caliper? money is tight as the moment so looking to save the pennys any which possible.

    just qurious, did yours disks and pads bind thus making them over heat like mine did?

    Graham
    Yes I do based on the fact parts are available whether or not a local garage will do the work is something else though, plus the time involved the labour costs could well make this an expensive option.

    Binding is a very common sympton of knacked seals.

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    all i am saying is that once the dust seal has hardened or split through pad replacement, it has been more beneficial and cost effective in the long run to exchange the caliper as each time i have removed the caliper from the car, i have found a degree of piston and bore scoring from dirt entering past the seal,which cannot be dealt with safely by any repair kit

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    According to the Haynes Manual, calipers from 1.4/1.6 engines and 1.8 engines without ABS are not serviceable, however those from 1.8 ABS engines and above can be serviced, though I'd guess others can be with the right bits.

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