Help with McGaughys 13" Rear Big Brake Install - The 1947 - Present Chevrolet & GMC Truck Message Board Network

NoNeck · 11-10-2012, 05:05 PM

Working on the installation of the McGaughys 13" Big Brake Kit for the rear of a '70 GMC. The brake caliper and pads will not clear the rotor when I snug the rotor (finger tight) to the axle flange. If I leave the rotor loose on the studs the caliper and pads slide right on. But, now the rotor will not fully seat against the axle flange. Either the C-bracket that mounts the caliper needs to be ground away about 1/16", or the rotor needs to be spaced away from the flange by 1/16".

We are using Moser Street Axles, but they measure exactly the same length as the 6 luggers that we took out. Same flange thickness, etc.

I contacted McGaughys on Thursday, and have not heard back from them (great customer service!). It shouldn't be this difficult. I'm beginning to wonder if this kit is as well engineered as advertised.

I have attached a few photos. Anybody had to deal with this problem before? Any advice would be appreciated.

POP

**lolife99** · 11-10-2012, 06:19 PM

Does the caliper bracket go on the back side of the axle flange?
I think that bracket goes on the other wheel.

NoNeck · 11-10-2012, 06:30 PM

Quote:

Does the caliper bracket go on the back side of the axle flange?

Keith,

According to the McGaughy's installation sheet (no photos, no diagrams), and I quote:
"Mount the McGaughy's rear disc conversion brackets onto the front side of the housing flanges with the welded offset towards the center of the housing. Brackets are to be mounted towards the rear of the housing."

As you can see in the photos, that's the way they are installed. If they were installed to the back (inside of the housing) the alignment would be way off.

POP

shawno72 · 11-10-2012, 06:41 PM

I think what Keith is saying is to take the bracket pictured and flip it around and use it on the other side of the axle. Another words move from passenger side to drivers side? Maybe I am way wrong, I was admiring the purdy axles

**lolife99** · 11-10-2012, 06:43 PM

Do the caliper bushings slide freely in the caliper?
Looks like the caliper needs to slide over a little on these.

**lolife99** · 11-10-2012, 06:57 PM

I linked the wrong thread.
http://67-72chevytrucks.com/vboard/s...=428379&page=5
Look at this same Mcgaughys kit,...

**lolife99** · 11-10-2012, 06:59 PM

Mount the McGaughy's rear disc conversion brackets onto the front side (disc caliper mounting bracket) of the housing flanges with the welded offset (housing mount bracket) towards the center of the housing. Brackets are to be mounted towards the rear of the housing."

**lolife99** · 11-10-2012, 07:02 PM

And another,...

NoNeck · 11-10-2012, 09:47 PM

Quote:

I think what Keith is saying is to take the bracket pictured and flip it around and use it on the other side of the axle. Another words move from passenger side to drivers side? Maybe I am way wrong, I was admiring the purdy axles
__________________
Shawn

So, this would put the C-bracket on the INSIDE of the axle tube? Man, the McGaughy's instruction sheet is useless!

We will try flipping the brackets tomorrow.

Thanks guys.

POP

NoNeck · 11-10-2012, 09:51 PM

Quote:

Do the caliper bushings slide freely in the caliper?
Looks like the caliper needs to slide over a little on these.

Yep, the bushings slide freely. We'll switch things around and see if that works.

POP

**pete63** · 11-05-2013, 11:02 PM

I know this is older tread, but wondering if a solution was found. I am having the same prob as op first post. I have switched bracket from side to side and lubed slide pins. It just seems like pads are to thick or caliper won't open up enough. I get everything tightened up and I can't even spin rotor. Like its locked up. Thanks

11-10-2012, 05:05 PM	#1
NoNeck Registered User Join Date: Jan 2011 Location: Chattanooga, TN Posts: 1,108	Help with McGaughys 13" Rear Big Brake Install Working on the installation of the McGaughys 13" Big Brake Kit for the rear of a '70 GMC. The brake caliper and pads will not clear the rotor when I snug the rotor (finger tight) to the axle flange. If I leave the rotor loose on the studs the caliper and pads slide right on. But, now the rotor will not fully seat against the axle flange. Either the C-bracket that mounts the caliper needs to be ground away about 1/16", or the rotor needs to be spaced away from the flange by 1/16". We are using Moser Street Axles, but they measure exactly the same length as the 6 luggers that we took out. Same flange thickness, etc. I contacted McGaughys on Thursday, and have not heard back from them (great customer service!). It shouldn't be this difficult. I'm beginning to wonder if this kit is as well engineered as advertised. I have attached a few photos. Anybody had to deal with this problem before? Any advice would be appreciated. POP Attached Images __________________ 2016 RAM Laramie HEMI 1966 Fairlane GT/A, 390/335 HP If it costs you a dollar to make a friend, KEEP THE DOLLAR. If it costs you a friend to make a dollar, KEEP THE FRIEND.

11-10-2012, 06:19 PM	#2
lolife99 67-72 parts collector,… Join Date: Nov 2002 Location: Mid-MO Posts: 22,700	Re: Help with McGaughys 13" Rear Big Brake Install Does the caliper bracket go on the back side of the axle flange? I think that bracket goes on the other wheel. __________________ Keith Convert to disc brakes. http://67-72chevytrucks.com/vboard/s...d.php?t=444823 Last edited by lolife99; 11-10-2012 at 06:25 PM.

11-10-2012, 06:41 PM	#4
shawno72 C/10 junkie Join Date: Nov 2010 Location: Stockton Ca Posts: 9,093	Re: Help with McGaughys 13" Rear Big Brake Install I think what Keith is saying is to take the bracket pictured and flip it around and use it on the other side of the axle. Another words move from passenger side to drivers side? Maybe I am way wrong, I was admiring the purdy axles __________________ Shawn 70 LWB C10 current driver/project http://67-72chevytrucks.com/vboard/s...d.php?t=663051 68 SWB C10 Work in progress.....SOLD http://67-72chevytrucks.com/vboard/s...d.php?t=559520 72 LWB C10 Sold 71 LWB C10 Sold 68 LWB C10 CST Sold http://youtu.be/kbB0QrBIs9k My mom always had the best advice. It was just a tad late. After a fall that involved blood, she'd say....."Careful!"

11-10-2012, 06:43 PM	#5
lolife99 67-72 parts collector,… Join Date: Nov 2002 Location: Mid-MO Posts: 22,700	Re: Help with McGaughys 13" Rear Big Brake Install Do the caliper bushings slide freely in the caliper? Looks like the caliper needs to slide over a little on these. Attached Images __________________ Keith Convert to disc brakes. http://67-72chevytrucks.com/vboard/s...d.php?t=444823

11-10-2012, 06:57 PM	#6
lolife99 67-72 parts collector,… Join Date: Nov 2002 Location: Mid-MO Posts: 22,700	Re: Help with McGaughys 13" Rear Big Brake Install I linked the wrong thread. http://67-72chevytrucks.com/vboard/s...=428379&page=5 Look at this same Mcgaughys kit,... Attached Images __________________ Keith Convert to disc brakes. http://67-72chevytrucks.com/vboard/s...d.php?t=444823

11-10-2012, 06:59 PM	#7
lolife99 67-72 parts collector,… Join Date: Nov 2002 Location: Mid-MO Posts: 22,700	Re: Help with McGaughys 13" Rear Big Brake Install Mount the McGaughy's rear disc conversion brackets onto the front side (disc caliper mounting bracket) of the housing flanges with the welded offset (housing mount bracket) towards the center of the housing. Brackets are to be mounted towards the rear of the housing." __________________ Keith Convert to disc brakes. http://67-72chevytrucks.com/vboard/s...d.php?t=444823

11-10-2012, 07:02 PM	#8
lolife99 67-72 parts collector,… Join Date: Nov 2002 Location: Mid-MO Posts: 22,700	Re: Help with McGaughys 13" Rear Big Brake Install And another,... Attached Images __________________ Keith Convert to disc brakes. http://67-72chevytrucks.com/vboard/s...d.php?t=444823

11-05-2013, 11:02 PM	#11
pete63 Active Member Join Date: Aug 2007 Location: wisconsin Posts: 112	Re: Help with McGaughys 13" Rear Big Brake Install I know this is older tread, but wondering if a solution was found. I am having the same prob as op first post. I have switched bracket from side to side and lubed slide pins. It just seems like pads are to thick or caliper won't open up enough. I get everything tightened up and I can't even spin rotor. Like its locked up. Thanks



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