Author Topic: Disc brake conversion grinding on slide pins  (Read 866 times)

JonG78TransAm

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Disc brake conversion grinding on slide pins
« on: February 17, 2022, 04:01:27 PM »
So I installed a LEED disc brake conversion kit on the rear of my 76 Pontiac Trans Am, stock rear end housing. Axle flange offset is 2.78, 10 bolt, c-clip style rear end w/staggered shocks. I ordered the kit linked below. Their technical support can not figure out why the rotors is touching the slide pins, I cannot figure it out either. They swore they've sold tons of these kits with no problem. I'm at loss at this point and wondering if anyone else has converted their rear end with a better kit or see's something wrong here. Thanks in advance.

https://leedbrakes.com/i-22264892-rear-disc-brake-conversion-kit-gm-10-12-bolt-axles-5-x4-75-with-staggered-shocks.html

Click to enlarge






Axle flange


And my baby for good measure lol :)



scarebird

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Re: Disc brake conversion grinding on slide pins
« Reply #1 on: February 17, 2022, 07:11:51 PM »
Their tech support is not worth much it seems.  One of 2 things is wrong here: the rotor is too big or the mount holes are in the wrong place (too far in).

Also, mounting it from behind the axle housing flange as they do is contemptible at the least - a very poor solution.  It is not machined to accept anything mounted to it.

Wallington

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Re: Disc brake conversion grinding on slide pins
« Reply #2 on: February 17, 2022, 07:34:14 PM »
Is that their new supplied rotor? Looks cruddy already and has been wet, maybe where parked. I wouldn't be surprised if they already had minimal clearance and a few rotors are on the cusp for dimensions, or a new rotor supplier. I'd confirm the diameter and then see what they say it should be.

JonG78TransAm

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Re: Disc brake conversion grinding on slide pins
« Reply #3 on: February 18, 2022, 10:07:13 AM »
This is a brand new kit, we had rain in texas and the rear end was apart on my shop lift outside, car had a car cover on it, but all the metal shavings on the rotor rusted up quick with the humidity. The rotor is the correct size. I will just buy a willwood kit which is $$ :(

81Blackbird

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Re: Disc brake conversion grinding on slide pins
« Reply #4 on: February 18, 2022, 10:43:23 AM »
Can you have the rotors turned to reduce the diameter?  How much do you think need to be shaved off?

Re: Disc brake conversion grinding on slide pins
« Reply #4 on: February 18, 2022, 10:43:23 AM »

Wallington

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Re: Disc brake conversion grinding on slide pins
« Reply #5 on: February 18, 2022, 05:17:41 PM »
Unless you are loaded with cash and can't get rid of it why would you just get another kit? It's an easy fix but more interesting as to why like that in the first place.

scarebird

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Re: Disc brake conversion grinding on slide pins
« Reply #6 on: February 19, 2022, 12:36:21 AM »
81 is right - just turn down 50 thou and you are done.

JonG78TransAm

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Re: Disc brake conversion grinding on slide pins
« Reply #7 on: February 20, 2022, 01:22:41 PM »
A couple reason I’d buy a new kit. I own an automotive shop, so the shop can expense things. If LEED won’t give me my money back for their kit then Amex will. Also shaving  down the rotor will make the pad not contact the rotor in full. You’ll develop a lip on the top of the pad. But the number one reason is this kit is obviously crap, every measurement was taken before ordering this kit.
It should work and it doesn’t. I ordered the Right Stuff kit for the same price which has good reviews. I only ordered this kit because at the height of COVID everything else was back ordered.

81Blackbird

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Re: Disc brake conversion grinding on slide pins
« Reply #8 on: February 21, 2022, 05:44:11 AM »
Hard to tell in the photos, but I don't thing you'll have to shave so much off that the pad will sit above the edge of the rotor.

firebirdparts

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Re: Disc brake conversion grinding on slide pins
« Reply #9 on: February 21, 2022, 10:57:58 AM »
Is that a GM caliper?

It's the caliper that's going to determine that the pads can somehow be above the pins.  That would be pretty weird.
I want to be like Paul Kenny when I grow up
Joe Bays
1977 Y82 4-speed (red interior)
1978 Skybird 350
1978 Redbird 305
1979 Redbird 301 4-speed
1992 Lincoln Mark VII LSC/SE (red)
1970 Datsun Pickup
1953 Chevy pickup (converted 4x4)
1988 T-bird Turbo Coupe

Wallington

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Re: Disc brake conversion grinding on slide pins
« Reply #10 on: February 21, 2022, 06:31:30 PM »
Unrelated to actual issue, do they sell kit as a factory rear disc upgrade or a drum upgrade? Different axle lengths, aren't they?

firebirdparts

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Re: Disc brake conversion grinding on slide pins
« Reply #11 on: February 23, 2022, 09:59:15 PM »
That's no upgrade.  I got curious and clicked the link.  reproduction Gm caliper with the internal acme screw parking brake.  So based on that, I guess hub centering could be a problem, depending on how thick the rotor is.
I want to be like Paul Kenny when I grow up
Joe Bays
1977 Y82 4-speed (red interior)
1978 Skybird 350
1978 Redbird 305
1979 Redbird 301 4-speed
1992 Lincoln Mark VII LSC/SE (red)
1970 Datsun Pickup
1953 Chevy pickup (converted 4x4)
1988 T-bird Turbo Coupe

Re: Disc brake conversion grinding on slide pins
« Reply #11 on: February 23, 2022, 09:59:15 PM »
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