Dumb Caliper Question

[Someday]

I have a 1971 C10 with stock front disk brakes. I am upgrading the front suspension with new coils and dropped spindles.

My question is how to remove the caliper off the rotor. I've removed the allen bolts and it's loose. The rotor has a machined groove around the front and rear of the rotor and the pads have a corresponding projection that fits into the groove. I can't get it the clear out of the groove to remove the caliper.

Sorry if it's a dumb question, I have searched google and this forum.

Thank you for any help

[HO455]

You need to collapse the puck back into the caliper body to allow the ridge the pad has to clear the groove. This link should help. The first way with the screwdriver should do the trick.

https://m.youtube.com/watch?v=3RYG0ymWEFE

[SavageC20]

Try sticking a big flathead screwdriver in between the pad and the rotor on the inside of the rotor to force the piston back into the caliper so you have more room to slide it off.

[Steeveedee]

Do one side at a time, or put a c-clamp on the caliper you removed first to keep it from popping apart when you compress the other caliper. You may not be pushing the piston that far into the caliper, but it's a good practice to use every time. Also pop the cap on the master cylinder to relieve the pressure when the fluid backs up into it.

[Someday]

Originally Posted by HO455

You need to collapse the puck back into the caliper body to allow the ridge the pad has to clear the groove. This link should help. The first way with the screwdriver should do the trick.

https://m.youtube.com/watch?v=3RYG0ymWEFE

Thank you for your reply!!!

[HO455]

You are welcome. And around here there are no dumb questions.

[Someday]

Originally Posted by SavageC20

Try sticking a big flathead screwdriver in between the pad and the rotor on the inside of the rotor to force the piston back into the caliper so you have more room to slide it off.

Thank you!!

[Someday]

Originally Posted by Steeveedee

Do one side at a time, or put a c-clamp on the caliper you removed first to keep it from popping apart when you compress the other caliper. You may not be pushing the piston that far into the caliper, but it's a good practice to use every time. Also pop the cap on the master cylinder to relieve the pressure when the fluid backs up into it.

Thank you!!

[AussieinNC]

A quick reply here...the disk should not have a groove or wear sufficient to prevent the caliper and pads from sliding off....

Do yourself a huge favor....replace the rotors, overhaul the calipers and install new brake pads....change out the rubber hoses that feed each caliper....

Then check the master cylinder where it mates to the booster....any sign of brake fluid leaks, replace the master cylinder...

NEVER SHORTCUT BRAKES....

[Someday]

Originally Posted by AussieinNC

A quick reply here...the disk should not have a groove or wear sufficient to prevent the caliper and pads from sliding off....

Do yourself a huge favor....replace the rotors, overhaul the calipers and install new brake pads....change out the rubber hoses that feed each caliper....

Then check the master cylinder where it mates to the booster....any sign of brake fluid leaks, replace the master cylinder...

NEVER SHORTCUT BRAKES....

Thank you. They groove I am talking about is machined into the rotor and the pad has a corresponding projection that fits into the groove. Thank you for your help!!

[71CHEVYSHORTBED402]

Originally Posted by Someday

Thank you. They groove I am talking about is machined into the rotor and the pad has a corresponding projection that fits into the groove. Thank you for your help!!

Hmm.........That kinda sounds like the pad "scraper" dug into your rotor. In other words, the rotor isn't machined, the scraper acts as a warning when the pads are bad, because it digs into the rotor.. As mentioned, new brakes.

[Someday]

Originally Posted by 71CHEVYSHORTBED402

Hmm.........That kinda sounds like the pad "scraper" dug into your rotor. In other words, the rotor isn't machined, the scraper acts as a warning when the pads are bad, because it digs into the rotor.. As mentioned, new brakes.

Interesting, the pad has a projection that fits into the uniform groove. My plan is to do the suspension upgrade and have my brakes checked by my mechanic. My truck only has 60K miles

[71CHEVYSHORTBED402]

Originally Posted by Someday

Interesting, the pad has a projection that fits into the uniform groove. My plan is to do the suspension upgrade and have my brakes checked by my mechanic. My truck only has 60K miles

Wow, 60K, it's due a brake job Tough to tell what you mean without pictures.

[clay68c10]

Factory rotors had a groove in the middle of the rotor face. Not sure why.

[HO455]

The factory rotors had a groove in the center of them and as the pads were worn down they ended up with a matching ridge on them. I have heard several theories as to why GM did this but nothing conclusive.

[Steeveedee]

Maybe it was minimum rotor thickness? Another possibility is it may eliminate squeals. I don't know for sure about either, but I've seen thousands with the groove.

[GASoline71]

All the disc brake rigs in the late 1960's early 1970's (not just trucks) had a groove in the rotor from the factory. Not sure why, but they did. I had a 1971 El Camino SS that had a grove in the front disc rotors as well.

Gary

[kwmech]

DO NOT SHOVE THE PADS BACK without cracking the bleeder screw. You'll shove all the dirty and sometimes overheated fluid back into the system. Crack it out the bleeder and push new/newer fluid downstream

[weq92f]

.
I dig that groove in the old rotors. In fact, I've got a set with the groove that are in pretty good shape ( need new races ). Think I'll have them turned, clean them up and install them!

The groove might serve as a rotor wear guide?


-klb

[GASoline71]

I'm not certain what the groove was for, but when I removed the rotors from my 1972 GMC C15 a couple years ago, they had the groove in them. The pads had the raised spot that matched the groove worn in to them as well. I replaced them with new rotors that have no groove, but I kep the old ones just because.

The only thing I hated about that stinkin' groove was that you had to press your caliper piston back quite a ways to get the old pads to clear so you could get the caliper/pads combo off the rotor.

Gary

[michael bustamante]

Originally Posted by 71CHEVYSHORTBED402

Hmm.........That kinda sounds like the pad "scraper" dug into your rotor. In other words, the rotor isn't machined, the scraper acts as a warning when the pads are bad, because it digs into the rotor.. As mentioned, new brakes.

the groove was put into original rotors as a wear indicator. when the groove is no longer visible, its time to replace the rotors

[GASoline71]

I believe these were the rotors that came from the factory on my 1972, as they still have the "tag" on them from the assembly line.



Gary

[Someday]

Wow, thank you for all your replies!!!

[mrein3]

Originally Posted by weq92f

.
I dig that groove in the old rotors. In fact, I've got a set with the groove that are in pretty good shape ( need new races ). Think I'll have them turned, clean them up and install them!

The groove might serve as a rotor wear guide?


-klb

Good luck getting them turned. I had a set off my 1971 Monte that I brought in to get turned. The guy wouldn't believe me that that groove was from the factory. I finally gave up, went to a different auto parts store to buy a new set, and stashed the originals for the next Chevelle project.

I have no way to confirm it but I was told by an old time mechanic that the groove was thought to help cooling.

[Steeveedee]

He would be wrong, since once the pad wore into the groove the minimal cooling effect would be gone.