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Technical How do you get pistons out of brake calipers?

Discussion in 'The Hokey Ass Message Board' started by WhitewallWill, May 22, 2022.

  1. Ebbsspeed
    Joined: Nov 11, 2005
    Posts: 6,250

    Ebbsspeed
    ALLIANCE MEMBER

    There is a giant percentage of H.A.M.B members that have no idea what you are talking about. It is a good joke, but it'll fly over the heads of most members like a jet propelled caliper piston.

    We had sheep and cattle on the farm.....
     
    VANDENPLAS, SS327 and WhitewallWill like this.
  2. jimvette59
    Joined: Apr 28, 2008
    Posts: 1,107

    jimvette59
    Member

    Send them out. The pistons are replaceable but how will the cylinder walls be ? Get then relined with stainless steel. JMO.
     
    nochop, WhitewallWill and egads like this.
  3. Budget36
    Joined: Nov 29, 2014
    Posts: 13,173

    Budget36
    Member

    Lol. My dad told me that joke when I was a kid, but it was how to fill the 2nd hump of a camel with water. When the camels balls were smacked the camel would go “whoosh” and suck in more water.
    I still chuckle about it today.
    And yes, I remember the little green spent “cheerios” on the ground as a kid, we had sheep when I was young.
     
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  4. WhitewallWill
    Joined: Mar 5, 2014
    Posts: 645

    WhitewallWill
    Member
    from N. Van, BC

    Ha ha, you might be right. I cling to my small town origins.
     
  5. WhitewallWill
    Joined: Mar 5, 2014
    Posts: 645

    WhitewallWill
    Member
    from N. Van, BC

    This is probably more likely than any scenario.
     
  6. Beanscoot
    Joined: May 14, 2008
    Posts: 3,053

    Beanscoot
    Member

    The walls of the caliper bores are not sealing surfaces, the bore needs to guide the piston and not bind on it (such as by rust). The finish on the groove that holds the seal is what needs to be of a high grade, so the brake fluid does not leak behind it. This is a sealing surface.
    Relining the caliper bores with stainless steel will not improve this groove unless the sleeve is so thick that it incorporates the groove, which might not be possible to do depending on the caliper body casting thickness.

    The dynamic sealing is between the seal and the piston, so the finish on the piston is the other critical area.
     
  7. Ebbsspeed
    Joined: Nov 11, 2005
    Posts: 6,250

    Ebbsspeed
    ALLIANCE MEMBER

    The green cheerios were used with the "elastrator". The emasculator is more painful.
     
    WhitewallWill likes this.
  8. Budget36
    Joined: Nov 29, 2014
    Posts: 13,173

    Budget36
    Member

    Is that the pair of plier looking things with a blade in the middle of two blocks?
     
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  9. Ebbsspeed
    Joined: Nov 11, 2005
    Posts: 6,250

    Ebbsspeed
    ALLIANCE MEMBER

    Yes it is.
    37419_L_vvs_000.jpg
     
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  10. WhitewallWill
    Joined: Mar 5, 2014
    Posts: 645

    WhitewallWill
    Member
    from N. Van, BC

    Oh ya, first time I ever held a set I thought what an instrument of horror. Then I met 'Spotty the steer'. He was mean and could push an electric fence over and would chase you just because. No warm and fuzzys for Spotty.
     
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  11. nochop
    Joined: Nov 13, 2005
    Posts: 3,818

    nochop
    Member
    from norcal

    Are they uber expensive? I’d get rebuilds done
     
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  12. WhitewallWill
    Joined: Mar 5, 2014
    Posts: 645

    WhitewallWill
    Member
    from N. Van, BC

    Went on the hunt, no one had Jag calipers. Local parts store didn't even have a listing for them. Ended up buying rebuild parts out of California which seemed excessive but, that was my option. I tried getting pistons out again today and I had one move a titch. Fabbed my shock mounts instead. Still marinating.
     
  13. RockAuto shows 'em, about $60 each rebuilt. Have the pistons too (about $8 each), but no seal kit for some reason. If you don't mind ordering the seals out of Britain, they're on eBay for about $40 for both sides.
     
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  14. brading
    Joined: Sep 9, 2019
    Posts: 704

    brading
    Member

    If you do decide to order seals for the Jag calipers from over here in the UK get them from this guy as then you will know they are the really deal.
    https://www.jagspares.co.uk/
     
    WhitewallWill likes this.
  15. Good description here, they are actually a displacement system, the pistons not carrying the seals but the bore. Bore fills up with fluid and displaces the piston.Only need to worry about the seal grooves or scores to the pistons.
    Clowns using air incorrectly can do some life changing damage. Grease or hydraulically moving them is much safer. Imho.
     
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  16. Moriarity
    Joined: Apr 11, 2001
    Posts: 30,773

    Moriarity
    SUPER MODERATOR
    Staff Member

    yes, simply re connect the brake hose from the car, use varying width wood blocks between and push them out with the brake pedal. all of this soaking with petroleum products is doing nothing more than swelling the seals and making them more difficult to get apart
     
    jaracer, VANDENPLAS, winr and 2 others like this.
  17. Thomas K.
    Joined: Dec 25, 2018
    Posts: 59

    Thomas K.
    Member

    Gibbs penetrant. Have never had it not work to free something up. Learned about it years ago at tractor shows.
     
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  18. RockAuto has them in stock, $62.79 with core. Screenshot 2022-05-24 at 07-28-11 1986 JAGUAR XJ6 4.2L L6 Caliper RockAuto.png
     
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  19. WhitewallWill
    Joined: Mar 5, 2014
    Posts: 645

    WhitewallWill
    Member
    from N. Van, BC

    Got pistons and seal kits. The seals between the calipers were not included. Gave them another bump with air yesterday and they are starting to move. Going to try the trans fluid/acetone trick if the deep creep doesn't get it done. Replacing all my brake lines so not complete enough to plumb yet and I don't have any plugs on hand. Getting some other much needed tasks done while I'm waiting.
    20220523_131011_resized.jpg
     
    brEad likes this.
  20. WhitewallWill
    Joined: Mar 5, 2014
    Posts: 645

    WhitewallWill
    Member
    from N. Van, BC

    And then there's this. Will have a run at these tonight after work. Will grab some plugs for the MC and get this done. Need my bench back, Calipers have Monopolized my work surface.
     
    Moriarity likes this.
  21. Moriarity
    Joined: Apr 11, 2001
    Posts: 30,773

    Moriarity
    SUPER MODERATOR
    Staff Member

    petroleum products will swell the seals and make it more difficult to remove the pistons
     
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  22. 34Phil
    Joined: Sep 12, 2016
    Posts: 553

    34Phil
    Member

    I screwed a zerk in my Jag caliper and got the grease gun
     
  23. WhitewallWill
    Joined: Mar 5, 2014
    Posts: 645

    WhitewallWill
    Member
    from N. Van, BC

    20220524_185029.jpg
    Just did that too. Basically all the effort was spent keeping the pistons that want to pop out in their bores. Went to get some cheap bulk grease in cartridges. Holy Chicken Little! No bulk just specialty stuff available.
     
    Beanscoot likes this.
  24. gconnsr
    Joined: Sep 14, 2008
    Posts: 144

    gconnsr
    Member
    from AZ

    Nitrous is pretty good at scattering pistons. Wrong approach. Good luck man.
     
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  25. mgtstumpy
    Joined: Jul 20, 2006
    Posts: 9,214

    mgtstumpy
    Member

    I had my Jag calipers down years ago, shop used pressurised grease to pop the pistons. From memory they wrapped them up in a towel and similarly used rags or a block of wood in between halves for when the pistons released.
     
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  26. WhitewallWill
    Joined: Mar 5, 2014
    Posts: 645

    WhitewallWill
    Member
    from N. Van, BC

    Done, sweet goldness.
    20220528_163223.jpg 20220528_162830.jpg
     
  27. SS327
    Joined: Sep 11, 2017
    Posts: 2,463

    SS327

    I wonder if you walked into a body shop with a pair of those if your car would get done faster. May be a way to end paint and upholstery jail.
     
  28. WhitewallWill
    Joined: Mar 5, 2014
    Posts: 645

    WhitewallWill
    Member
    from N. Van, BC

    Clank, So - I'd like to talk about schedule.
     
  29. B.A.KING
    Joined: Apr 6, 2005
    Posts: 4,039

    B.A.KING
    Member

    Love this thread ,from how to get brake pistons loose, to de Nutting!!! GOTTA LOVE THE HAMB......................
     
  30. Flathead Freddie
    Joined: May 9, 2021
    Posts: 806

    Flathead Freddie
    Member

    Hi Everyone ,

    So Whitewall I read the complete thread and the definition of Spray and Soak is to spray , spray again , let it set in for a couple a days and spray again and tapping around with a brass hammer . On tapping style it's best to tap in quick repetitions like an air chisel not forceful ones . Keep the metals under a constant vibration we call this shocking the metals . So ok I'll spill the beans yes I was a Jag mechanic Rolls Royce also all that rich stuff so you got 80s binders well those are good but all that English stuff had quirky metallurgy so some froze more than others and I'm in SoCal so worked in SoCal shops with a SoCal die angle and die grinder and with a SoCal vice which I put the caliper in then created a notch usually with the die grinder and a cutting wheel both SoCal of course and alot of Beach Cities and South Bay Lol . Then I put my SoCal air chisel in my Beach Cities/South Bay hand and go figure the rest and that will definitely be out in 5 minutes and most likely in 30 seconds then I put out my South Bay hand and collect my Beach Cities money . Total time to rebuild a locked caliper has to be in under 45 minutes or your rolling your tools out the shop to go scrape pennies off the shop floor of a dealership . And yes you want Jag parts like I do you will buy the Jag tools and the special dictionary that I've always said should come with every Jag . I love Jags and my wallet was always open for someone's repair bill .
    So ya wanna do this without soaking just go to town with an air chisel and pop some air in as it's in the vise and do grab a handful of rags unless you already look like you play hockey but know that dangerous and dumb are best of pals so use the rags . Don't worry this will happen again and now you know it's no big deal . I only used the die grinder on maybe one out of 25 locked calipers as I usually use the flat face barrel chisel bit 12 o'clock to 6 o'clock to 3 o'clock to 9 o'clock .
    Class is dismissed and Keep Your Foot In It !
     
    WhitewallWill likes this.

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