4 Piston Big Brake Upgrade from 2019-20

[Dantheman1540]

I'm gonna check tonight and see if a NBS 2 piston front caliper will bolt up to the rear. If it does I'll order a 13.5 NNBS rear rotor and a 4 piston test caliper and see if my theory on putting the T1 4pistons in the rear is possible.

 

[ks03]

I'm gonna check tonight and see if a NBS 2 piston front caliper will bolt up to the rear. If it does I'll order a 13.5 NNBS rear rotor and a 4 piston test caliper and see if my theory on putting the T1 4pistons in the rear is possible.

The bracket mounting holes look a lot closer together on the rears
Front

rear

 

[fasteddy]

I'm gonna check tonight and see if a NBS 2 piston front caliper will bolt up to the rear. If it does I'll order a 13.5 NNBS rear rotor and a 4 piston test caliper and see if my theory on putting the T1 4pistons in the rear is possible.

That would be awesome!
Good luck with test fit.
I think I backed off on that because of the rear rotor clearance.
But all is possible.

 

[Rocket Man]

I'm gonna check tonight and see if a NBS 2 piston front caliper will bolt up to the rear. If it does I'll order a 13.5 NNBS rear rotor and a 4 piston test caliper and see if my theory on putting the T1 4pistons in the rear is possible.

Pretty sure they’re not even close but that’s going from memory and I’m old af.

 

[Dantheman1540]

The bracket mounting holes look a lot closer together on the rears
FrontView attachment 344953

rearView attachment 344954

That would be awesome!
Good luck with test fit.
I think I backed off on that because of the rear rotor clearance.
But all is possible.

Pretty sure they’re not even close but that’s going from memory and I’m old af.

Totally right those pics are awesome @ks03. Nowhere near close which is kinda expected but knowing H2s used NBS front calipers in the rear I thought there was a chance. Now I need to look at H2 rear brake mounting plates. I have a buddy with an H2 axle in his Tahoe so hes gonna get some pics sometime for me, I'll do some googling tomorrow at work as well.

If it's as easy as swapping brake backing plates I would be okay with that. Pulling axles shafts suck but it's a good time to do out wheel bearings.

 

[Dantheman1540]

More stuff I've come up with since it's bugging me. The H2 rear calipers and NBS fronts are the same part number (Sorta already knew this but part number confirmation is nice) as are their mounting brackets which are separate removable pieces on those 2pots. There for the only thing that could make the difference between H2 rear and NBS rear mounting is the bracket mounting plate on the axle and I confirmed it with Gmpartsdirect.

So the H2 plates are discontinued by GM but it looks like Summit still has some and they may be interchangeable with 3/4ton vans and some NBS HD trucks. I'll order a set and see if they will mount to the axle, might go pick up a NBS Tahoe 10bolt at the scrap yard for testing. Since I just resealed my 14b and don't want to do testing like this on the daily.

 

[corvette744]

More stuff I've come up with since it's bugging me. The H2 rear calipers and NBS fronts are the same part number (Sorta already knew this but part number confirmation is nice) as are their mounting brackets which are separate removable pieces on those 2pots. There for the only thing that could make the difference between H2 rear and NBS rear mounting is the bracket mounting plate on the axle and I confirmed it with Gmpartsdirect.

So the H2 plates are discontinued by GM but it looks like Summit still has some and they may be interchangeable with 3/4ton vans and some NBS HD trucks. I'll order a set and see if they will mount to the axle, might go pick up a NBS Tahoe 10bolt at the scrap yard for testing. Since I just resealed my 14b and don't want to do testing like this on the daily.

IF i remember correctly the h2 is a 3/4 ton truck frame chassis and drivetrain and just drop the hummer body on it.

 

[Dantheman1540]

IF i remember correctly the h2 is a 3/4 ton truck frame chassis and drivetrain and just drop the hummer body on it.

Yes and no, the rear axle is not a full floater like the HD trucks had. It's a 9.5sf 14bolt much like the AXN models from NNBS 6.2 2wd suvs and also found sometimes in 05-06 Escalade 6.0 2wd SUVs. The difference between the AXN and H2 (IIRC) is the outer shafts are not necked down as much leaving larger outer wheel bearings and 8 lug thug shafts. They are very similar to the late 90s HD 1/2ton axles just 8 lug instead of 6.

Being they they share a lot in common with the AXN then they are also very similar to the 10bolts and looking at the backer plate pictures it sure looks like it might work. If not then at least i have a backer plate to take measurements off of and make a custom bracket.

 

[91RS]

The H2 is basically a 2500 non-HD or 1500 HD.

 

[mikeyss]

The H2 is basically a 2500 non-HD or 1500 HD.

But didn't the H2 use the 4L65 until 06? I know the 1500 HD came with the 4L80. The H2 was all sorts of mixed up, haha.