4 Piston Big Brake Upgrade from 2019-20

[SRQYukon]

Dont know if I could sleep at night if I had plastic caliper covers.

MGP has powder-coated aluminum for Tahoe/Yukon, but they're still a little cheesy and expensive, like

 

[Rocket Man]

Just say no to caliper covers. And yes the NBS larger dual piston rear calipers fit the NNBS. Before this latest mod, it was known to to be the best OEM setup by running the NNBS fronts with the NBS rears- best of both worlds. But now it seems the best setup would be the 2019-2020 fronts with the 00-06 rears. Everything is interchangeable with the exception of wheel issues with these 19-20’s.

 

[SRQYukon]

Nooooo!

 

[ks03]

For whatever reason I never cared much what the calipers look like, I always thought big rotors make it sexy.

 

[Dantheman1540]

Just say no to caliper covers. And yes the NBS larger dual piston rear calipers fit the NNBS. Before this latest mod, it was known to to be the best OEM setup by running the NNBS fronts with the NBS rears- best of both worlds. But now it seems the best setup would be the 2019-2020 fronts with the 00-06 rears. Everything is interchangeable with the exception of wheel issues with these 19-20’s.

I think they were discussing if the NBS 2 piston calipers would fit over a NNBS 13.5" rotor.

 

[joeg]

Can someone measure the barrel clearance needed to fit the 4pot calipers? I know it's probably a longshot, but I'm wondering if you could clear the barrel in an aftermarket 16" wheel. They're -12 offset, so I'm not worried about the width.

 

[Dantheman1540]

On my recent road trip, I was brainstorming about possible rear upgrades and might have come up with something worth checking into. Hummer H@s came with NBS front calipers on their rear axles but a custom 8lug rotor. The rear axle on an H2 is a 9.5sf 14bolt but has a little bigger shafts, and outer bearings (I think that's the main difference). If an NBS front caliper fits on an H2 9.5sf then it might fit an AXN 9.5sf that comes in the NNBS 6.2/2wd trucks which happen to come with 13.5" rotors in the rear.

What else has a 13.5" rotor? Oh yeah the T1 4 piston calipers this post is dedicated to are designed for a 13.5"rotor. So maybe just maybe we could put a T1 4piston caliper and pads on an NNBS 13.5" rear rotor on the back of an NBS rig while retaining the parking brake and have it all bolt up with no more than a simple washer to space it.

Obviously, this has not been put together in person I'm just spitballing and seeing what yall think.

Another issue everybody likes to bring up when talking about brakes is bias, with nearly identical braking power front>rear I would assume the rear would be more likely to lock up. I do know the NBS ABS is fairly good and may be able to overcome this but if not a proportioning valve would be needed.

 

[George B]

On my recent road trip, I was brainstorming about possible rear upgrades and might have come up with something worth checking into. Hummer H@s came with NBS front calipers on their rear axles but a custom 8lug rotor. The rear axle on an H2 is a 9.5sf 14bolt but has a little bigger shafts, and outer bearings (I think that's the main difference). If an NBS front caliper fits on an H2 9.5sf then it might fit an AXN 9.5sf that comes in the NNBS 6.2/2wd trucks which happen to come with 13.5" rotors in the rear.

What else has a 13.5" rotor? Oh yeah the T1 4 piston calipers this post is dedicated to are designed for a 13.5"rotor. So maybe just maybe we could put a T1 4piston caliper and pads on an NNBS 13.5" rear rotor on the back of an NBS rig while retaining the parking brake and have it all bolt up with no more than a simple washer to space it.

Obviously, this has not been put together in person I'm just spitballing and seeing what yall think.

Another issue everybody likes to bring up when talking about brakes is bias, with nearly identical braking power front>rear I would assume the rear would be more likely to lock up. I do know the NBS ABS is fairly good and may be able to overcome this but if not a proportioning valve would be needed.

The only experience with bias was when I gutted a proportioning valve on an 82 Caprice. It had closer to 50/50 bias and would stop ok but there was very little weight transfer to the fronts and steering suffered under even moderate braking if you needed to steer or corner. Might not be apples to apples but maybe the physics apply.

 

[SRQYukon]

On my recent road trip, I was brainstorming about possible rear upgrades and might have come up with something worth checking into. Hummer H@s came with NBS front calipers on their rear axles but a custom 8lug rotor. The rear axle on an H2 is a 9.5sf 14bolt but has a little bigger shafts, and outer bearings (I think that's the main difference). If an NBS front caliper fits on an H2 9.5sf then it might fit an AXN 9.5sf that comes in the NNBS 6.2/2wd trucks which happen to come with 13.5" rotors in the rear.

What else has a 13.5" rotor? Oh yeah the T1 4 piston calipers this post is dedicated to are designed for a 13.5"rotor. So maybe just maybe we could put a T1 4piston caliper and pads on an NNBS 13.5" rear rotor on the back of an NBS rig while retaining the parking brake and have it all bolt up with no more than a simple washer to space it.

Obviously, this has not been put together in person I'm just spitballing and seeing what yall think.

Another issue everybody likes to bring up when talking about brakes is bias, with nearly identical braking power front>rear I would assume the rear would be more likely to lock up. I do know the NBS ABS is fairly good and may be able to overcome this but if not a proportioning valve would be needed.

Has anyone tried a Wilwood master cylinder with the 2019-20 setup to see if it would provide better bias balance? Does it have a larger fluid reservoir?

 

[Dantheman1540]

So far nobody has seemed to need one, I certainly don't feel it would be necessary with my current setup of T1 4pot upfront and NBS 2pot in the rear.

 

[Rocket Man]

So far nobody has seemed to need one, I certainly don't feel it would be necessary with my current setup of T1 4pot upfront and NBS 2pot in the rear.

I haven’t needed one with my 16”/ 6 piston fronts and 14.25/ 4 piston rears but maybe because they’re proportional?

 

[Dantheman1540]

I haven’t needed one with my 16”/ 6 piston fronts and 14.25/ 4 piston rears but maybe because they’re proportional?

I think people overthink a lot of stuff, I've always thought the master cylinders in these trucks seemed huge compared to almost anything built pre 2000.

 

[91RS]

There were a bunch of people saying the master wouldn’t work with 4 and 6 piston calipers but here we are.

 

[Dantheman1540]

There were a bunch of people saying the master wouldn’t work with 4 and 6 piston calipers but here we are.

H8ers gonna h8

 

[George B]

There were a bunch of people saying the master wouldn’t work with 4 and 6 piston calipers but here we are.

It’s all about the total surface area of the caliper pistons. If the sum of the four or six pistons is equal to the surface area of the stock single or dual piston all is well.

 

[SRQYukon]

I never said it was necessary to upgrade the master cylinder. It was just a simple question "has anyone tried the Wilwood mc with the 2019-2020 4-piston setup?" I'm not trying to over-think it. I'm just trying to research all my options before I start the installation. I have no plan to replace the stock master cylinder unless there is an issue. Several posters had raised the question about the adequacy of the stock mc with the 4-piston setup. It appears from the feedback from those who have already completed the install and used it, that there have been no issues. Does that mean we have to stop the discussion? I thought that was the purpose of the forum. Right? This is neither a stock setup nor a true aftermarket setup like Wilwood, Brembo, or Baer. It's a hybrid setup that deserves a review of the collective knowledge of those that have done this. I see frequent postings with major problems after truck mods where it is very obvious that DIY'er did little or no homework. I don't roll that way. This is my DD and I need minimal downtime when I do an upgrade.

 

[Dantheman1540]

I never said it was necessary to upgrade the master cylinder. It was just a simple question "has anyone tried the Wilwood mc with the 2019-2020 4-piston setup?" I'm not trying to over-think it. I'm just trying to research all my options before I start the installation. I have no plan to replace the stock master cylinder unless there is an issue. Several posters had raised the question about the adequacy of the stock mc with the 4-piston setup. It appears from the feedback from those who have already completed the install and used it, that there have been no issues. Does that mean we have to stop the discussion? I thought that was the purpose of the forum. Right? This is neither a stock setup nor a true aftermarket setup like Wilwood, Brembo, or Baer. It's a hybrid setup that deserves a review of the collective knowledge of those that have done this. I see frequent postings with major problems after truck mods where it is very obvious that DIY'er did little or no homework. I don't roll that way. This is my DD and I need minimal downtime when I do an upgrade.

Sorry if I came off sounding like a jerk that was not intended at all! I agree it's great to continually discuss mods like this and get as much real-world user feedback as possible because most SUVs like that are DDs. I have seen no negative effects on or due to the master cylinder being inadequate so I don't believe it's necessary to make any changes with the 4pistons up front and 2 in the rear. But if the option I was brainstorming would work it may be necessary to have an option to change the bias due to having equal braking force front and rear.

Who has that test caliper right now?

 

[ks03]

I would be curious if any issue that seemed to be the size of the master cylinder was actually just a bleeding issue, or squishy brake lines. Before the new calipers could the pedal travel just as far under hard application, or was that even checked? The guy in the first video looks like he has less than new rubber lines, and there’s enough video of the line hanging, dripping that I’d question whether he’s being mindful of how hard it is to get all the air out of a master cylinder if he let it get too low.

 

[TheAutumnWind]

I'll try to remember to take some pics along the way. I'm terrible with that. Especially once I get my hands dirty and greasy. Probably wouldn't be good for my iPhone to wipe it with BrakeClean

Why not? Should be waterpoof. I clean my phones with alcohol. Whats the difference?

 

[FrankU]

Dantheman1540 ....I sent the caliper to tRidiot , that's the last time it surfaced.

I'd like to do the 2 piston rears. Gonna need them.The 2021 calipers etc are here waiting to be installed so might as well do the 2 piston rears while in there. Wilwood brakes was the first choice but the extra money went to Whipple (also waiting install) Whipple was supposed to take 6-8 weeks and that would give me time to do the brakes first. Help me put together a rear 2 piston set up ?