6 lug 4x4 brake upgrade

I figured I'd share my brake upgrade with the forum.

I have an 88 4x4 Suburban and I am slowly upgrading it. This upgrade needs 16 inch or bigger rims depending on rim shape and fitment. I'm running 17's.



Here's where we start, a stock 10 bolt front end




I'm going with Hummer H3 four piston calipers and rotors in a disk over hub arrangement.

The brackets and idea came from Thorparts.com, he's using a GM 10 bolt front and machining the brackets and hubs to integrate the ABS brake system to a solid axle conversion for the H3 Hummers. Less involved for us squarebodies.

Take your hub assemblies apart, cut the outer hub down to 7 inches, drill the lug holes to fit your choice of lugs, and basically bolt it up. I went with larger 14x1.5 lug studs from a 02 chevy 4x4 front.

The H3 uses a larger center hub so it slips right over, only the flange outer diameter needs cut down to fit the disks on. My local parts store did it on a brake lathe, easy and quick.

My eventual goal is to swap in a complete rear axle from a 99-06 Silverado, giving me matching rear disks and a parking brake, with matching 14x1.5 lugs.

With the adaptor plate and caliper bolted up



Uses slip over rotor and calipers from an H3 Hummer 2006 and up.Best fit for me was 39/64 holes to fit the late model lugs. I opened up the hub and rotors with a 39/64 drill bit, but the holes could be a couple thousands smaller. It was more than close enough for me, I did use red Loctite when installing the lug studs.
The brackets make it a basic bolt on affair. Other than what your truck came with you need:

thorparts brackets
39/64 drill bit (though a couple thousands less would be perfect)
twelve lug studs and nuts from the front of a 2002 Silverado
rotors and calipers from a 2006 or up H3 (normal one not the special edition)
and brake lines (uses the same 10mmx1.5 banjo bolt as my stock burb), as I have a 2.5 lift, at Advance Auto parts, getting Dorman H38620 and H38621 @ $15 each. Correct for both ends and right at 4 inches longer. From a 99 Tahoe I believe.

Here's the completed hub with studs



And with the rotor slipped over



A top view



The final issue I ran into was rim to caliper clearance, I had to use a 1/4 spacer to get the rim face from contacting the caliper. Rim choice will be important with this install. I'm sure a set of factory H3 rims or Silverado rims with the center opened up would fit just fine, then the choice of offset enters the picture.





It's getting zero vibrations, clean smooth running, stops very well even though I still need to final bleed and bed the brakes.

On a last note, once I get to swapping in a 99-02 Silverado rear axle, I'll also change the master cylinder to the 02 Silverado style. Should bolt in with a single thread adaptor like the OBS to NBS upgrade.

Dude thanks for posting this! I wonder if the same applies for a 2wd

Nope, it's dana 44/chevy 10 bolt front 4x4 only.

Darn oh well. Thanks!

A little follow-up. I installed a 2004 Silverado disk brake rear axle to complete my brake upgrades.


The axle is a couple inches wider than the square body axles, making the track width almost the same as the front, so spacers in the rear are not needed. Also gives me the larger 14x1.5 lugs like I did in the front. All using factory parts and having parking brakes. Even the u joint was the same size. You need to move the spring plates and shock mounts, then add a brake line extension (thread sizes are the same also). Done in the rear.



So we have a total of 10 pistons of brake calipers, larger rotors, parking brakes, larger lugs, keeping the same lug pattern and using factory parts. The best mod I've done yet. Stops like I've never had a large truck do.

My concern is that you are using a much larger caliper that can our stock master cylinder provide the same amount of pressure to the pads?

And you could just grind down the caliper where ever its rubbing or touching.. always lots of meat.

And how much money do you have invested in this?

firebane said:

My concern is that you are using a much larger caliper that can our stock master cylinder provide the same amount of pressure to the pads?

And you could just grind down the caliper where ever its rubbing or touching.. always lots of meat.

And how much money do you have invested in this?

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Is it really larger though? And instead of putting all the force to 1 large piston, it is being spread between 4 smaller, which should help with the brake force.

flyboy1100 said:

Is it really larger though? And instead of putting all the force to 1 large piston, it is being spread between 4 smaller, which should help with the brake force.

Click to expand...

Well that is the question.. And the experts will have to chime in.

The front was a total of $300 and the rear was also $300.
The front rotors are 12.4" diameter and the rear can be 12" or 13" depending on which truck you get it from.
I am also planning a swap to a late model master cylinder, but as always it's a time and money thing. Mostly right now time. The master will run about $70 from Rock auto.

If you want a more detailed installed, you'll need to check my post on Coloradok5 under a title of "pure chevy sex" (I know, but it is sexy).

Another advantage is the front calipers are FIXED, no slider issues. With the separate inside/outside pistons, the caliper never gets stuck. The servicing of the front is also easier with disk over hub. Disks and lugs are replaceable without pulling the hubs.

Grinding the calipers is not really an option, you will have to run 16" or bigger rims. And it can be picky on rim selection due to caliper width.

Larger modern brakes are always a better option. If you can get them to fit. And here is a great way to upgrade our old trucks, using almost all factory parts.

cyclic said:

The front was a total of $300 and the rear was also $300.
The front rotors are 12.4" diameter and the rear can be 12" or 13" depending on which truck you get it from.
I am also planning a swap to a late model master cylinder, but as always it's a time and money thing. Mostly right now time. The master will run about $70 from Rock auto.

If you want a more detailed installed, you'll need to check my post on Coloradok5 under a title of "pure chevy sex" (I know, but it is sexy).

Another advantage is the front calipers are FIXED, no slider issues. With the separate inside/outside pistons, the caliper never gets stuck. The servicing of the front is also easier with disk over hub. Disks and lugs are replaceable without pulling the hubs.

Grinding the calipers is not really an option, you will have to run 16" or bigger rims. And it can be picky on rim selection due to caliper width.

Larger modern brakes are always a better option. If you can get them to fit. And here is a great way to upgrade our old trucks, using almost all factory parts.

Click to expand...

$300 isn't too bad for everything considering the costs of having to replace discs and pads especially good pads.

When you say you cut down the outer hub to 7" I assume your referring to the part sticks through the rim?

The outer diameter of the hub assembly. The part where the lugs are. Just reducing the outer diameter enough to clear the inside of the rotor hat. It can be done on a standard brake lathe once the hub is pulled and the stock disk and lugs removed.

A little late to the party. It looks like Thorparts is all but out of business. Do you have pics of the H3 setup installed? Your original post is missing pics. Thinking about putting a Dana44 under the front of my 99 Suburban, and would like something more than stock half ton brakes, while maintaining 6 lugs.

GreaseDog said:

A little late to the party. It looks like Thorparts is all but out of business. Do you have pics of the H3 setup installed? Your original post is missing pics. Thinking about putting a Dana44 under the front of my 99 Suburban, and would like something more than stock half ton brakes, while maintaining 6 lugs.

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Howdy stranger!

This is similar to a question I asked about using 04 or such rear disks on my 94 6 lug 14b SF.
I almost think you could just unbolt from the axle tube mounting out and move it over.

Stock 15s would probably not fit though.