Caliper rebuild with pictures.
 

OK I just rebuilt the calipers in my Nova. Seems like this is a bit of a lost procedure given the cost of rebuilt calipers. I thought I would go through and show the process I use. Now, this may or may not be the text book method, I don't know. It's the way I've rebuilt hundreds if not thousands of calipers over the last 20 years or so. The GM single piston is about as simple as they come.

Here we have the caliper in all it's unwashed glory. Notice I have an old pad between the caliper "fingers" and the piston. I'd rather not have the piston slam into the caliper.



Using compressed air I'm going to force the piston out of the bore. This is no time to put your fingers in the way. I'll tell you for a fact that hurts really bad.



I use another rag like this to keep the fluid from flying all over. If you have a customer that likes to stand right over you and watch you work this step can be skipped. :crazy:



The piston pops out.



Pull the piston out. Take a screw driver like this and wedge the dust seal out. You may have to do this in multiple places.



Pull the seal out of the bore.



This one isn't too bad. I've seen a lot worse. Remember nothing seals in the bore. The o-ring we pulled out of the groove seals on the piston Get it clean but don't stress over perfection. Some of the stains will not come out. As long as it's smooth you are good. Get the groove very clean.



The piston is fairly bad, but will clean up.



A little brake clean, elbow grease and a scotchbrite pad and we have a usable piston again. You can use krocus cloth or if you're careful a wire wheel. It has to be smooth. Any pitting or groves means you need to replace it.

The bore cleaned up pretty much the same way. I used a screw driver to scrape the crap out of the bottom.



Now we need to assemble. Start with the dust seal.

Push it down to get the lip into the grove on the piston





And then pull it up to sit on top of the piston.



Now comes the o-ring seal, just put it in place no real trick to it. I didn't even take a picture. :)

Get the lube out.


And liberally coat the piston and bore. Make sure you coat the o-ring seal.



Place the piston in the bore and gently rock it back and forth until it starts to slide in. If you need anything other than your hands to compress it you either need to eat more Wheaties or you have it cocked.



Once the piston is in the bore tap the outside of the dust seal into the caliper. Here you see I have a tool just for that. In the past I've used a punch and even a screw driver when desperate. Don't slip off the ring with either or you will puncture the boot.

And we have an assembled caliper ready for service.



I've been preaching the importance of hardware for a bit now. Lets take a look at what I'm talking about.

These little buggers look like they are pretty unimportant. There pretty simple but are often over looked, as they were with my Nova.



It consists of a sleeve

and o-ring


And the grove in the caliper


I replaced mine, more on why in a bit. If the o-ring is OK you can clean and lube the sleeve and move on. They need to be really clean but use enough lube to let them slide up and down with your fingers, but not enough to attract all kinds of dirt.

Remember, the other side of the caliper has a smaller o-ring that rides on the pin. It needs to be changed too. Pay attention to the end of the pin. This picture doesn't show it well, but the end is grooved and will hinder caliper movement and they need to be replaced.

The sleeves on my Nova had to be forcefully driven out with a punch and harmer. I suspect this was my pull and my brake pull. The caliper could not slide back and held the right brake slightly on. Pay close attention to these slides because they are the source of a lot of brake complaints.

I hope this post helps someone. If you have any questions or corrections feel free to ask or reply. :)




It's important

And we have an assembled caliper ready for service.



I've been preaching the importance of hardware for a bit now. Lets take a look at what I'm talking about.

These little buggers look like they are pretty unimportant. There pretty simple but are often over looked, as they were with my Nova.



It consists of a sleeve

and o-ring


And the grove in the caliper


I replaced mine, more on why in a bit. If the o-ring is OK you can clean and lube the sleeve and move on. They need to be really clean but use enough lube to let them slide up and down with your fingers, but not enough to attract all kinds of dirt.

Remember, the other side of the caliper has a smaller o-ring that rides on the pin. It needs to be changed too. Pay attention to the end of the pin. This picture doesn't show it well, but the end is grooved and will hinder caliper movement and they need to be replaced.


The sleeves on my Nova had to be forcefully driven out with a punch and harmer. I suspect this was my pull and my brake pull. The caliper could not slide back and held the right brake slightly on. Pay close attention to these slides because they are the source of a lot of brake complaints.

With the low cost of replacement calipers it may seem like a waste of time to rebuild your own. IMO when I'm done with the job I know for a fact it was done right. The rebuild kits were $2 each, the hardware kit was another $3 for both sides. Well under the cost of a rebuilt caliper and I trust my work over some dude on an assembly line any day of the week.

I hope this post helps someone. If you have any questions or corrections feel free to ask or reply. :)

How long did it take to rebuild them.

It takes me about 15 minutes a side start to finish. I'd say the average hobbyist could have both done in 45 minutes to an hour.

Nice How-To. Would be a good Stickie. I have an old set of calipers ,maybe I'll do a rebuild while Camaro is stored. Thanks

Great information. Who sells the kit with the O rings to do this job?

Rockauto does, any auto parts store should be able to order them for you.

O-Rings
DORMAN Part # D35494 More Info {First Stop #5468767, 8124574, J8124574, J8126755}
Front; Bore = 2-15/16" $1.77

RAYBESTOS Part # WK524 More Info {Professional Grade}
Front $2.06


Hardware:
ACDELCO Part # 18K265 More Info {#18034594, 18034639, 18K220}
CALIPER KIT,FRT BRK DURASTOP
$3.62



You know, reman calipers are only like $20, but after going through a number of remans with casting issues, this may be the way to go.



"stickied"

Plus you know the ones that came off your car will fit (should :crazy: ) back on.
And the owners concerned about numbers matching are happy.

P.S. I did this with my original calipers; excellent pictorial :cool:

Gary

Nice job Dave. I remember when the O rings and sleeves for the slide bolts were included in the brake pad box. Now they charge extra for them.

The calipers I purchased for the Nova had metric holes for the banjo bolt and the old ones were SAE. Another reason why rebuilding what you have makes good sense.

Daver's,

I'm just curious,,,,how come you didn't get the calipers powder coated when you had them apart?????

Did you want to keep the original look?????

Nice pictorial,,,,,,,but you must've been either 390 (drunk) or a better camera for the close up shots...LOL!!...

Allen

Thanks for going back to the basics for everyone Dave!

Takes time to do the lesson and photograph step by step but this is one of those basic service things too many people take for granted and need to know!

There's another thread I replied to about calipers causing uneven wear and need to refer the OP to this thread!

Powder coating brakes? That cost money and a normal hobby man wouldn't waste money on something like that when they aren't seen through the wheel anyway! They would buy beer! :crazy:

Thanks for this, I bought a book on rebuilding alot of this stuff, now I can visualize it. It was nice to take the time to photo the process for us.