# rebuilding 4 piston disc caliper on 68 GTO



## jayvee53 (Aug 26, 2018)

Hello all,

I am hoping someone can give me guidance about rebuilding the four piston calipers on the front disc brakes on a 68 GTO. I have read about the issues with these calipers and the pros and cons and have decided I wanted to try to keep my car as original as possible which will mean servicing the calipers. I see various vendors sell rebuild kits which look to be pretty simple but.... 

Any help would be greatly appreciated!

John


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## BLK69JUDGE (Jun 10, 2010)

its your brakes .. send em out to

https://whitepost.com/brake-sleeving-rebuilding-services/

do it once ... and they are good forever 

send em your original master also

dont forget to do your rear wheel cylinders tooooooooooooo

they get forgotton ... I have original 7/8 delco morraine rear wheel cylinder cores if needed .... and extra 4 piston disc calipers if needed also

bust em in half ... if the 2 bolts are tight ... they DO brake ... I have done it ...
soak em a couple times
for a coupe days ...
with pb blaster or such 

Scott


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## jayvee53 (Aug 26, 2018)

BLK69JUDGE said:


> its your brakes .. send em out
> 
> do it once ... good forever
> 
> ...


 Thanks Scott! I appreciate the reply. I have found a YouTune video of a guy rebuilding a four piston caliper on a car other than a GTO, but looks like the general procedure will apply


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## Sixty7GTO (May 4, 2017)

Hello, 
I will be looking to rebuild my OEM 4-piston calibers. BLK69Judge, you had mentioned sending them "Out" Where would I send them. Do you have a name of someone that rebuilds these calibers?
I have heard and have read the correct way to rebuild these calibers is to bore them and install stainless steel inserts and then new pucks and a seal kit. I have found a couple of options that I'm considering. "Cardone" will rebuild them if you fill out the form they have on their website. 2, you can buy new 4-piston calibers for about $160-$170 each, but they won't have the correct casting numbers and they might have the small piston version as used on the early Corvettes. 3, You can buy the new pucks and the seal kits but you have to find a local machine shop that can bore the calipers, a total of 8 holes in a tolerance of +/- , 2-4 thousands. The stainless sleeves have to be made to fit the new pucks and seals and pressed in and honed. All of this can add up very quickly, money wise. I'm leaning toward sending mine to "Cardone" and hope for the best. My fear is that they will lose them in the normal run of the mill rebuilding process, Or you'll get a pair back that were not your original casting numbers.
Honestly, I don't have a definitive answer with the research I have done. We need someone to chime in here that has gone through this process. I have jotted down the part numbers that are the replacement. You can look up the numbers on Amazone and "CARID" websites and others. I've seen them on eBay as well.


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## BLK69JUDGE (Jun 10, 2010)

sorry I was in a hurry posting

here is the link for white post ....

https://whitepost.com/brake-sleeving-rebuilding-services/

very nice timely work ....
not cheap but very fair prices ....
quality work on the stuff I have had done 

1940 chevy wheel cylinders and master cylinder for my car...
several sets of sleeving only on 7/8" rear delco morraine wheelcylinders

several 67-70 master cylinders also

Scott


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## jayvee53 (Aug 26, 2018)

Sixty7GTO said:


> Hello,
> I will be looking to rebuild my OEM 4-piston calibers. BLK69Judge, you had mentioned sending them "Out" Where would I send them. Do you have a name of someone that rebuilds these calibers?
> I have heard and have read the correct way to rebuild these calibers is to bore them and install stainless steel inserts and then new pucks and a seal kit. I have found a couple of options that I'm considering. "Cardone" will rebuild them if you fill out the form they have on their website. 2, you can buy new 4-piston calibers for about $160-$170 each, but they won't have the correct casting numbers and they might have the small piston version as used on the early Corvettes. 3, You can buy the new pucks and the seal kits but you have to find a local machine shop that can bore the calipers, a total of 8 holes in a tolerance of +/- , 2-4 thousands. The stainless sleeves have to be made to fit the new pucks and seals and pressed in and honed. All of this can add up very quickly, money wise. I'm leaning toward sending mine to "Cardone" and hope for the best. My fear is that they will lose them in the normal run of the mill rebuilding process, Or you'll get a pair back that were not your original casting numbers.
> Honestly, I don't have a definitive answer with the research I have done. We need someone to chime in here that has gone through this process. I have jotted down the part numbers that are the replacement. You can look up the numbers on Amazone and "CARID" websites and others. I've seen them on eBay as well.


Hello Sixty7GTO,
I would be interested in more information regarding your research. I was thinking simply replacing the seals, dust boots and O-rings would be sufficient maintenance on a caliper that is in good working order, just needing a bit of a refresh/update. What you are discussing is obviously way beyond that. What would the condition of the caliper be in order to need the extensive work you are thinking about? Maybe seized or inoperative? I always appreciate the insight of others who have been researching or who have experience with the same issues I am working on. Thanks in advance for any response from you or others who care to post! 

John


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## PontiacJim (Dec 29, 2012)

jayvee53 said:


> Hello Sixty7GTO,
> I would be interested in more information regarding your research. I was thinking simply replacing the seals, dust boots and O-rings would be sufficient maintenance on a caliper that is in good working order, just needing a bit of a refresh/update. What you are discussing is obviously way beyond that. What would the condition of the caliper be in order to need the extensive work you are thinking about? Maybe seized or inoperative? I always appreciate the insight of others who have been researching or who have experience with the same issues I am working on. Thanks in advance for any response from you or others who care to post!
> 
> John



I think is is you who is adding to the confusion in the answers. You provided several options, most all of which seem to indicate the need to address the caliper piston bores.

If they are working calipers, then rebuild them yourself with a kit. I would first disassemble them, then bring the caliper halves to a machinist with the bore dimensions and have them check for roundness and size. Then go from there.

You can use stainless or brass. I used these guys for a 1948 International master cylinder. They sleeved it and installed a rebuild kit. Looked like new. I recall it was $170 and fast turn around time. You can have just the calipers sleeved if needed and then you install your rebuild kit or have them do the complete rebuild. You can check their prices out. https://www.applehydraulicsonline.com/pages/contact


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## dd68gto (Nov 14, 2012)

These calipers used on 68 and I think 67 gto were the same that were on the corvette. They were prone to leaks and seizeimg . Unless you are trying to keep it number matching I would strongly suggest you convert to the 69 duel caliber. You cans do the swap yourself in s few hours for a huge saving . The Pontiac dealers were even doing this change when 68 brakes were and issue and kept causing problems the four piston were kept only for the purist with the high money Vetts . Many write ups on this. I have s 68 gto with the upgrades 69 calipers. Never and issue. Replace caliper last year for 25 dollars . Doug


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## jayvee53 (Aug 26, 2018)

Thanks Doug!


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## UroDoc (Feb 4, 2021)

dd68gto said:


> These calipers used on 68 and I think 67 gto were the same that were on the corvette. They were prone to leaks and seizeimg . Unless you are trying to keep it number matching I would strongly suggest you convert to the 69 duel caliber. You cans do the swap yourself in s few hours for a huge saving . The Pontiac dealers were even doing this change when 68 brakes were and issue and kept causing problems the four piston were kept only for the purist with the high money Vetts . Many write ups on this. I have s 68 gto with the upgrades 69 calipers. Never and issue. Replace caliper last year for 25 dollars . Doug


I have a 1968 GTO with original front disc brakes. I have had issues with a leaking caliper after rebuild. I am considering installing 1969 single piston calipers. Will the 1969 calipers fit on the original 14" Rally II wheels?


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