Dumb Caliper Question - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Someday · 03-28-2019, 03:40 PM

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** · 03-28-2019, 03:55 PM

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

Someday · 03-28-2019, 07:17 PM

Quote:

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** · 03-28-2019, 07:22 PM

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

SavageC20 · 03-28-2019, 03:56 PM

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** · 03-28-2019, 07:10 PM

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 · 03-28-2019, 07:24 PM

Quote:

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** · 03-28-2019, 08:26 PM

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 · 03-28-2019, 09:28 PM

Quote:

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!!

Someday · 03-28-2019, 07:23 PM

Quote:

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!!

**clay68c10** · 03-29-2019, 06:55 AM

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

**HO455** · 03-29-2019, 08:43 AM

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** · 03-29-2019, 10:42 AM

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 · 03-29-2019, 11:05 AM

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** · 03-29-2019, 11:24 AM

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 · 03-29-2019, 12:22 PM

.
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

mrein3 · 03-30-2019, 10:58 AM

Quote:

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** · 03-30-2019, 11:13 AM

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

GASoline71 · 03-29-2019, 12:39 PM

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

GASoline71 · 03-29-2019, 12:46 PM

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 · 03-29-2019, 12:50 PM

Wow, thank you for all your replies!!!

03-28-2019, 03:40 PM	#1
Someday Registered User Join Date: Apr 2013 Location: Lodi, Ca. Posts: 50	Dumb Caliper Question 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

03-28-2019, 03:55 PM	#2
HO455 Post Whore Join Date: Feb 2016 Location: Portland Oregon Posts: 11,475	Re: Dumb Caliper Question 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 __________________ Thanks to Bob and Jeanie and everyone else at Superior Performance for all their great help. RIP Bob Parks. 1967 Burban (the WMB),1988 S10 Blazer (the Stink10 II),1969 GTO (the Goat), 1970 Javelin, 1952 F2 Ford OHC six 4X4, 29 Model A, 72 Firebird (the DBP Bird). 85 Alfa Romeo If it breaks I didn't want it in the first place The WMB repair thread http://67-72chevytrucks.com/vboard/s...d.php?t=698377

03-28-2019, 07:22 PM	#4
HO455 Post Whore Join Date: Feb 2016 Location: Portland Oregon Posts: 11,475	Re: Dumb Caliper Question You are welcome. And around here there are no dumb questions. __________________ Thanks to Bob and Jeanie and everyone else at Superior Performance for all their great help. RIP Bob Parks. 1967 Burban (the WMB),1988 S10 Blazer (the Stink10 II),1969 GTO (the Goat), 1970 Javelin, 1952 F2 Ford OHC six 4X4, 29 Model A, 72 Firebird (the DBP Bird). 85 Alfa Romeo If it breaks I didn't want it in the first place The WMB repair thread http://67-72chevytrucks.com/vboard/s...d.php?t=698377

03-28-2019, 03:56 PM	#5
SavageC20 Registered User Join Date: Sep 2018 Location: California Posts: 151	Re: Dumb Caliper Question 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. Last edited by SavageC20; 03-28-2019 at 04:03 PM.

03-28-2019, 07:10 PM	#6
Steeveedee Who Changed This? Join Date: Jan 2013 Location: Simi Valley, CA Posts: 10,790	Re: Dumb Caliper Question 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. __________________ ~Steven '70 Chevy 3/4T Longhorn CST 402/400/3.56 Custom Camper Simi Valley, CA

03-28-2019, 08:26 PM	#8
AussieinNC Moderator Join Date: Jun 2017 Location: Cherryville, NC Posts: 2,205	Re: Dumb Caliper Question 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.... __________________ Family and country before all others... 2006 Chevy Silverado (Daily Driver) 2012 Chevy Equinox

03-29-2019, 06:55 AM	#11
clay68c10 Senior Member Join Date: Aug 2004 Location: Centennial, CO Posts: 2,996	Re: Dumb Caliper Question Factory rotors had a groove in the middle of the rotor face. Not sure why. __________________ ClusterTruck: 68 C10 Bought in 89, wrecked in 03. Slow low $ rebuild started '17. 6.0 & TKO http://67-72chevytrucks.com/vboard/s...d.php?t=788602 93 K1500 Short Step, 350, NV4500, EBL flash ECU. Vortec heads & roller cam someday... 05 Jeep Wrangler Unlimited. 3” lift & 6-speed 02 E320 the insurance total “free car” 13 Tahoe LTZ

03-29-2019, 08:43 AM	#12
HO455 Post Whore Join Date: Feb 2016 Location: Portland Oregon Posts: 11,475	Re: Dumb Caliper Question 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. __________________ Thanks to Bob and Jeanie and everyone else at Superior Performance for all their great help. RIP Bob Parks. 1967 Burban (the WMB),1988 S10 Blazer (the Stink10 II),1969 GTO (the Goat), 1970 Javelin, 1952 F2 Ford OHC six 4X4, 29 Model A, 72 Firebird (the DBP Bird). 85 Alfa Romeo If it breaks I didn't want it in the first place The WMB repair thread http://67-72chevytrucks.com/vboard/s...d.php?t=698377

03-29-2019, 10:42 AM	#13
Steeveedee Who Changed This? Join Date: Jan 2013 Location: Simi Valley, CA Posts: 10,790	Re: Dumb Caliper Question 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. __________________ ~Steven '70 Chevy 3/4T Longhorn CST 402/400/3.56 Custom Camper Simi Valley, CA

03-29-2019, 11:24 AM	#15
kwmech Senior Member Join Date: Mar 2003 Location: Colfax-California Posts: 8,679	Re: Dumb Caliper Question 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

03-29-2019, 12:22 PM	#16
weq92f Registered User Join Date: Oct 2016 Location: Dallas Texas Posts: 3,267	Re: Dumb Caliper Question . 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 __________________ 67 C10 fleet fuel injected '70 402, 700r4, 3.73 posi 07 335 sport turbo 6sp 94 Trans Am GT LT1 6sp posi -- sold after 22yrs 99 540 sport V8 6sp -- sold 73 240z L24 4sp -- given to friend 68 C10 step 350/350 3.73 open -- sold

03-30-2019, 11:13 AM	#18
Steeveedee Who Changed This? Join Date: Jan 2013 Location: Simi Valley, CA Posts: 10,790	Re: Dumb Caliper Question He would be wrong, since once the pad wore into the groove the minimal cooling effect would be gone. __________________ ~Steven '70 Chevy 3/4T Longhorn CST 402/400/3.56 Custom Camper Simi Valley, CA

03-29-2019, 12:50 PM	#21
Someday Registered User Join Date: Apr 2013 Location: Lodi, Ca. Posts: 50	Re: Dumb Caliper Question Wow, thank you for all your replies!!!



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