C30 or 35 rear disc conversion?

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louu

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Before I get to the main question for the thread, I'll start off with a quick dumb question. What's the difference between c30 and c35 and how do I know witch one I have?

I just got this 86 C3?00 and am wondering if anyone has done a rear disc brake conversion or if anyone has any opinions on them.

Witch kit and from where did you get it?

Will it work as good as the stock drum brakes?

Did you have any trouble getting the emergency brake cables to work or any other problems with the emergency brake?

Here's my truck to maybe sort out the 30 or 35 question.

Thanks everyone

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Craig 85

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Chevy C30. GMC C3500.

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Bennyt

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Personally, I'd stick with drums unless you plan on never towing/ hauling again. You'd have to spend some big bucks to get a disc set-up for a 1 ton that performs as well or as reliably as a drum brake. I have used various brackets like diy4x, ord, tsmmfg, etc and the Caddy calipers and while they are lighter and easier to maintain, they definitely don't have the stopping power of a big drum set-up.
 

Rusty Nail

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I converted a 14 bolt to disc and im not happy AT ALL about it.
A disc conversion is the same cost as rebuilding OE drums and if I would have done that, my axle wouldn't be leaking now. PLUS now I dont have a parking brake.

I'll certainly not do it again. I recommend sticking with OE drums.
 

TubeTruck

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First of all, nice truck!

Second, if you want a disc brake setup in the back and have any fab skills, or friends with them, get a newer '01-'10 dually rear. It's just a matter of cutting off the spring perches and welding on a new set to fit under your truck. These newer rears come with the "drum in hat" e-brake which is easier to adapt and have the same bolt pattern, but they are 14mmx1.5mm studs so you'll need new lugnuts.

I'm no expert so I'm not sure if the newer dually rears are 10.5" ring gear, they might be all 11.5" but don't quote me on that, lol.
 

Turbo4whl

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Listen to what @Rusty Nail and @Bennyt stated. My '98 3500HD just doesn't stop as well as the same models with drum rear brakes. The e-brake is a drum on the trans, fortunately, that does work okay .

Rebuild the brakes you have.
 

louu

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Chevy C30. GMC C3500.

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Thanks bud but unfortunately there all gone off of my truck. The only ones on it are the gmc on the tailgate and the 3+3 on the side behind the rear door. Oh and the Sierra Classic gmc on the dash
 

louu

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I converted a 14 bolt to disc and im not happy AT ALL about it.
A disc conversion is the same cost as rebuilding OE drums and if I would have done that, my axle wouldn't be leaking now. PLUS now I dont have a parking brake.

I'll certainly not do it again. I recommend sticking with OE drums.

That's all I need to hear, thanks guys I'll be rebuilding the drums because the main reason I got this rig is to tow our camper.
 

louu

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Personally, I'd stick with drums unless you plan on never towing/ hauling again. You'd have to spend some big bucks to get a disc set-up for a 1 ton that performs as well or as reliably as a drum brake. I have used various brackets like diy4x, ord, tsmmfg, etc and the Caddy calipers and while they are lighter and easier to maintain, they definitely don't have the stopping power of a big drum set-up.

Thanks bud I tried to quote you to in the above post but I'm not very good at computer lol
 

louu

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First of all, nice truck!

Second, if you want a disc brake setup in the back and have any fab skills, or friends with them, get a newer '01-'10 dually rear. It's just a matter of cutting off the spring perches and welding on a new set to fit under your truck. These newer rears come with the "drum in hat" e-brake which is easier to adapt and have the same bolt pattern, but they are 14mmx1.5mm studs so you'll need new lugnuts.

I'm no expert so I'm not sure if the newer dually rears are 10.5" ring gear, they might be all 11.5" but don't quote me on that, lol.
Thanks for the reply bud, I definitely love this truck. It's almost impossible to go anywhere in it though because everyone wants to check it out lol. I'll be sticking with the drums
 

louu

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Listen to what @Rusty Nail and @Bennyt stated. My '98 3500HD just doesn't stop as well as the same models with drum rear brakes. The e-brake is a drum on the trans, fortunately, that does work okay .

Rebuild the brakes you have.

Thanks man, hopefully I have some time this weekend to rebuild the drums
 

louu

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So update, I fixed/replaced the whole brake system except for the seepage from the hydroboost system, I'll get to that later. What a difference, theses stock drums must grab hard and the fronts are awesome to. This truck stops on a dime now, way better than my 02 Silverado with 4 wheel disk.
 

Bextreme04

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Thanks bud but unfortunately there all gone off of my truck. The only ones on it are the gmc on the tailgate and the 3+3 on the side behind the rear door. Oh and the Sierra Classic gmc on the dash

In that case, you know its a GMC Sierra Classic 3500 and would have the same emblem that is shown in Craigs picture for the Sierra Classic.
 

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I converted a 14 bolt to disc and im not happy AT ALL about it.
A disc conversion is the same cost as rebuilding OE drums and if I would have done that, my axle wouldn't be leaking now. PLUS now I dont have a parking brake.

I'll certainly not do it again. I recommend sticking with OE drums.


If the axle is leaking at the wheel bearing seal, you probably have a groove from wear on the stub of the housing that is causing the leak. You have two options, pound on a bearing sleeve seal saver which works 50/50 but is $10 or upgrade to the later style seals for about $100. You can get them through ord.
 

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