J55 Caliper Rebuild
11-07-2010, 09:52 AM
#1
Burning Brakes
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J55 Caliper Rebuild
'91 ZR-1...
I'm starting my winter projects a little early, and want to rebuild the calipers. I'm staying stock, and want to do the fronts first.
What part numbers should I be looking for? It seems like there are a few variations out there, and frankly, I don't know what I'm going to get when I place an order.
Here's what I found so far:
A/C Delco # 173-511
A/C Delco # 18H170
A/C Delco # 18H86
It looks like 173-511 has been replaced by 18H170, but Limey/White Racing lists both. From what I can tell on his website, part/kit 173-511 contains two piston seals, two boots, a bleeder screw cap, and a c-clip, where as 18H170 contains just two seals and two boots.
The A/C Delco site shows 18H86 containing only one seal and one boot. The problem though is the pictures of 18H170 and 18H86 on the A/CD site show what appear to be different seals and boots.
Here's the next problem. Since I want to add speed bleeders, it doesn't seem like I wolud need the bleeder screw cap. But where do I find a part number for the c-clip? NAPA wasn't much help, and I can't find anything online.
Can someone point me in the right direction?
Doc
I'm starting my winter projects a little early, and want to rebuild the calipers. I'm staying stock, and want to do the fronts first.
What part numbers should I be looking for? It seems like there are a few variations out there, and frankly, I don't know what I'm going to get when I place an order.
Here's what I found so far:
A/C Delco # 173-511
A/C Delco # 18H170
A/C Delco # 18H86
It looks like 173-511 has been replaced by 18H170, but Limey/White Racing lists both. From what I can tell on his website, part/kit 173-511 contains two piston seals, two boots, a bleeder screw cap, and a c-clip, where as 18H170 contains just two seals and two boots.
The A/C Delco site shows 18H86 containing only one seal and one boot. The problem though is the pictures of 18H170 and 18H86 on the A/CD site show what appear to be different seals and boots.
Here's the next problem. Since I want to add speed bleeders, it doesn't seem like I wolud need the bleeder screw cap. But where do I find a part number for the c-clip? NAPA wasn't much help, and I can't find anything online.
Can someone point me in the right direction?
Doc
11-07-2010, 10:02 AM
#2
Le Mans Master
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The J55 use the same kit as the reg '88+ front calipers
Some other kit part # 's
Ecklers is a bit pricey
http://www.ecklers.com/corvette-brak...1988-1996.html
There is a cheaper GM kit around with a new pin and C clip
Some other kit part # 's
Ecklers is a bit pricey
http://www.ecklers.com/corvette-brak...1988-1996.html
There is a cheaper GM kit around with a new pin and C clip
Last edited by pewter99; 11-14-2010 at 11:35 AM. Reason: Non supporting vendor/other Corvette site link
11-08-2010, 09:00 PM
#4
Burning Brakes
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Jay, No kidding. I probably will get them done in silver. I'm sticking with the stock '91 sawblades, so they are not very conspicuous. I think a nice silver would look well. I'll probably paint the hats as well just because.
Rod: I followed the link to the other forum, but couldn't really understand what that post was trying to say.
Basically I have two questions:
(1) What kit(s) to do I need to complete the front calipers (axle set)?
(2) In addition to boots and seals, do I need to replace the retaining clips?
Rod: I followed the link to the other forum, but couldn't really understand what that post was trying to say.
Basically I have two questions:
(1) What kit(s) to do I need to complete the front calipers (axle set)?
(2) In addition to boots and seals, do I need to replace the retaining clips?
11-09-2010, 01:29 AM
#5
Melting Slicks
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I haven't done a caliper rebuild in decades. If I recall it was a simple as can be conceptually, but a PITA to actually do. Getting the boots and seals to get into their new homes correctly. I imagine whatever your local autoparts store supplies is fine. Unless the retaining clips appear week or are damaged they can be re-used. But if you don't want to, they are probably only a couple of dollars to replace.
The more important part is get them clean. Flush out all the brake fluid with new when bleeding. Don't let the master cyl run dry durring the flush/bleed process. Replace the crush washers on the banjo bolts that connect the hose, this is important due to the hole in the bolt has little tolarance at the depth it needs to be. If the washer is too crushed the bajo will seat too deap restricting the oil flow or cutting it off compleatly. You might want to replace the hoses if they look cracked.
Once done, it will feel like you did something wrong until the system settles in. I think it is the abs sorting itself out. I upgraded to 13" J55's and it took a mile or so before my brakes felt right, so take it easy at first.
The more important part is get them clean. Flush out all the brake fluid with new when bleeding. Don't let the master cyl run dry durring the flush/bleed process. Replace the crush washers on the banjo bolts that connect the hose, this is important due to the hole in the bolt has little tolarance at the depth it needs to be. If the washer is too crushed the bajo will seat too deap restricting the oil flow or cutting it off compleatly. You might want to replace the hoses if they look cracked.
Once done, it will feel like you did something wrong until the system settles in. I think it is the abs sorting itself out. I upgraded to 13" J55's and it took a mile or so before my brakes felt right, so take it easy at first.
Last edited by Jay Axson; 11-09-2010 at 01:32 AM.
11-15-2010, 07:06 PM
#7
Melting Slicks
Its a real easy job, I found the most important tool to be a toothpick to pull out the old seal without damaging the bores. Coincidently, I have probably replaced a dozen sets of J55 calipers over the last 7 seven years, having raced them and thermally spread the calipers leading to replacement(with used unraced calipers.) Every time I swapped calipers, I popped the pistons out because I was reusing my stainless steel pistons and I have never seen a damaged or torn seal and I never changed the circlip either. The only part I have seen wear on does not seem to be in the kits you described and that is the pin that the circlip fits on. If you are not seeing a leak past your pistons, I don't see the point(unless you do the powdercoating.) Speedbleeders, new fluid and a good flush is all you need.
