Further info on c3500 to 1/2 ton Caliper swap from a old thread

A97obs · Mar 26, 2024

I ran across a “2011 thread” about 1/2 ton caliper upgrades, swapping 2500 or 3500 calipers ,but there was never any elaboration on whether it was only the same concept to do this on a 2wd swap.
I’m trying to get some insight on whatever become of the option to run 3/4 or 1ton calipers directly bolt onto c1500 2wd spindle , which were said to bolt right on? I’m looking to do the same thing..
What I didnt find out was if you had to use a 2wd 2500 or 3500 caliper or 4wd 2500 /3500 caliper?
Anyways it was said you can bolt a 1 ton caliper right to a 1/2 ton truck for braking upgrade and keep your c1500 calipers and rotors but wasn’t specified whether you needed to swap the 2500/3500 rotor or if you can retain your stock 1/2 ton 5 lug rotor ?
I have to stay 5 lug with my wheel investment, so hoping the caliper swap is doable ? Wether using a 2500 or 3500 2wd swap caliper

Alternatively there’s some options I seen Online for “power stop” calipers that reviewed decent for better stopping efficiency, JEGS item and a few other sellers … any suggestions or info on the above swap would be greatly appreciated

1998_K1500_Sub · Mar 26, 2024

What’s the RPO code for your brakes on that 5-lug you own?

The issue boils down to matching the calipers and the MC; if you want the larger piston calipers you’ll need to pair them with the proper MC. You’ll find this discussed in GMT400 threads in the context of “low-drag” (or not) calipers and ”quick-take-up” (or not) MCs.

Search for “86mm” (use the forum’s search feature) and read through the related threads, most of them are recent.

The 86mm (3.38”) piston calipers are the largest, then 80mm (3.15”), then 76mm (3.0”), and reportedly there was a 63.5mm (2.5”) caliper used on the JN3 brakes.

All calipers are bolt on / interchangeable. You need not swap rotors / knuckles.

Generally the 76mm calipers were common on the lighter 5- and 6-lug trucks with RPO JB5/JB6 brakes, the larger calipers on the heavier ones.

This thread might be a place to start:

https://www.gmt400.com/threads/upgrade-front-brake-calipers.58795/

The pad choice is key to performance, and there are threads on that topic. Raybestos Element3 pads seem to have fans.

AFAIK there was never an alternative GMT400 caliper design — dual-piston / four-piston — offered by the third party vendors. Anything you might find is simply the same caliper that you can get from RockAuto, maybe snazzier w/ red powdercoat.

(Edit: See later posts below which reference the SSBC third-party caliper)

A97obs · Mar 26, 2024

1998_K1500_Sub said:
What’s the RPO code for your brakes on that 5-lug you own?

The issue boils down to matching the calipers and the MC; if you want the larger piston calipers you’ll need to pair them with the proper MC. You’ll find this discussed in GMT400 threads in the context of “low-drag” (or not) calipers and ”quick-take-up” (or not) MCs.

Search for “86mm” (use the forum’s search feature) and read through the related threads, most of them are recent.

The 86mm piston calipers are the largest, then 80mm, then 76mm, and reportedly there was an even smaller piston caliper used on the JN3 brakes.

All calipers are bolt on / interchangeable. You need not swap rotors / knuckles.

Generally the 76mm calipers were common on the lighter 5- and 6-lug trucks with RPO JB5/JB6 brakes, the larger calipers on the heavier ones.

This thread might be a place to start:

https://www.gmt400.com/threads/upgrade-front-brake-calipers.58795/

The pad choice is key to performance, and there are threads on that topic. Raybestos Element3 pads seem to have fans.

AFAIK there was never an alternative GMT400 caliper design — dual-piston / four-piston — offered by the third party vendors. Anything you might find is simply the same caliper that you can get from RockAuto, maybe snazzier w/ red powdercoat.

I’ll read more on the topics . I already scanned a bit on this.. all I really wanted to know for sure was if I can direct bolt a 2wd 2500 or 3500 caliper right onto a 2wd 1/2 ton spindle and keep my stock rotors ! That was important to know before throwing money at calipers .

I can’t change my spinels or anything cause I have rc lift spindles .

Even with all being single piston there were a few successful mentions of the upgrade swap being a firmer stop then stock offers , in addition to the nbs master upgrade
I am also either doing the rear disc nbs swap using the 20mm hub spacers from Cunningham alternately Or the 82” Eldorado calipers and pad swap . Depends what goes on easiest.

1998_K1500_Sub · Mar 26, 2024

A97obs said:
Even with all being single piston there were a few successful mentions of the upgrade swap being a firmer stop then stock offers , in addition to the nbs master upgrade

If you already had the NBS MC I would say "Fine". I have the NBS MC and it seems to work well; my pedal pressure w/ vacuum assist is comfortable.

BUT, if starting from a blank slate (and knowing what I know now), and IF I was NOT planning to use rear discs, I would use the GMT400 MC for JB7 brakes b/c the piston diameter is better suited for the GMT400 calipers.

Having said that...

A97obs said:
I am also either doing the rear disc nbs swap using the 20mm hub spacers from Cunningham alternately Or the 82” Eldorado calipers and pad swap . Depends what goes on easiest.

If you're planning the NBS rear discs, I would suggest the NBS MC (it's got the larger reservoir for the rear discs). Then, put the larger diameter GMT400 calipers on the front b/c (a) the NBS MC isn't a "quick-take-up" MC, so you must pair it with the non-low-drag 80mm or 86mm calipers and (b) you can then select a caliper piston diameter (80mm or 86mm) to (re)establish proper F/R brake balance.

Notably the NBS MC has a 34mm bore (e.g., ACDELCO 18M1159) which is larger than the stock GMT400 MC (1.25" or 1.125" bore, depending on application). A larger caliper piston balances / offsets the larger bore of the NBS MC.

After a bit of thought: If you use the NBS rear discs, you might want to use a GMT400 caliper that has a piston area that's roughly equivalent to the total area of the corresponding GMT800 dual-piston calipers... and you'll need to use either the 80mm or the 86mm calipers b/c they're non-low-drag (as I noted earlier).

Let's see what others say...

:popcorn:

sewlow · Mar 26, 2024

1998_K1500_Sub said:
What’s the RPO code for your brakes on that 5-lug you own?

The issue boils down to matching the calipers and the MC; if you want the larger piston calipers you’ll need to pair them with the proper MC. You’ll find this discussed in GMT400 threads in the context of “low-drag” (or not) calipers and ”quick-take-up” (or not) MCs.

Search for “86mm” (use the forum’s search feature) and read through the related threads, most of them are recent.

The 86mm piston calipers are the largest, then 80mm, then 76mm, and reportedly there was an even smaller piston caliper used on the JN3 brakes.

All calipers are bolt on / interchangeable. You need not swap rotors / knuckles.

Generally the 76mm calipers were common on the lighter 5- and 6-lug trucks with RPO JB5/JB6 brakes, the larger calipers on the heavier ones.

This thread might be a place to start:

https://www.gmt400.com/threads/upgrade-front-brake-calipers.58795/

The pad choice is key to performance, and there are threads on that topic. Raybestos Element3 pads seem to have fans.

AFAIK there was never an alternative GMT400 caliper design — dual-piston / four-piston — offered by the third party vendors. Anything you might find is simply the same caliper that you can get from RockAuto, maybe snazzier w/ red powdercoat.

Twin piston direct replacement.

A181 Front Quick Change Caliper Kit (Pair)

FRONT CALIPER UPGRADE KIT FOR GM METRIC APPLICATIONS 2- Piston ‘Sport Twin’ Aluminum Calipers **Note: Must be used with stock sized rotors This made in the USA kit contains all the parts you need to upgrade your GM metric to new light-weight, sport twin Aluminum calipers. Manufactured from...

ssbc-usa.com

A97obs · Mar 26, 2024

sewlow said:
Twin piston direct replacement.

A181 Front Quick Change Caliper Kit (Pair)

FRONT CALIPER UPGRADE KIT FOR GM METRIC APPLICATIONS 2- Piston ‘Sport Twin’ Aluminum Calipers **Note: Must be used with stock sized rotors This made in the USA kit contains all the parts you need to upgrade your GM metric to new light-weight, sport twin Aluminum calipers. Manufactured from...

ssbc-usa.com

Them are pricey calipers
Makes me wonder if the sweet spot fix is just with mostly the nbs firm feel master upgrade …or if it’s in addition to the caliper and pad swap. I assume the master swap just fixes the travel slop issue the pedal has and not necessarily the brake grab.

I was told or should I say recommended as an option if starting from scratch stay with the gmt400 master and use the jb7 brakes with the stock gmt400 calipers. Not sure why but that’s what one person advised or recommended.
That may be a better option than swapping to the nbs master . I’m just unsure what to do it’s a lot of unknowns and opinions but at the end of the day it’s just trial and error and money to see what works or fails expectations. If I actually kept drum brakes in the rear I wonder if doing front upgrade would make up for the stopping power

1998_K1500_Sub · Mar 26, 2024

A97obs said:
I was told or should I say recommended as an option if starting from scratch stay with the gmt400 master and use the jb7 brakes with the stock gmt400 calipers. Not sure why but that’s what one person advised or recommended.

As I noted in my earlier post, the NBS MC has a larger piston bore (34mm bore) than the JB7 MC (1.25" bore), by quite a margin (~15% greater area). Translation: The NBS MC will require more pedal pressure, when compared to the JB7 MC, under similar braking conditions.

Stating it differently: For the same pedal pressure, and all other things being equal, the JB7 MC will (should) provide greater braking effect.

Don't fall in love with the NBS MC. I have the NBS MC, and for me it works well, but if I was doing it all over again I would use the JB7 MC.

Either MC (NBS or JB7) *must* be used with the larger 80mm or 86mm for the reasons I noted... I'll take this opportunity to (re)emphasize this.

1998_K1500_Sub · Mar 26, 2024

sewlow said:
Twin piston direct replacement.

The proper p/n is SSBC A186, shown here:

A186-1 Front Quick Change Caliper Upgrade Kit

1988-1999 GM 1500 2WD/4WD FRONT CALIPER UPGRADE KIT-SUPER TWIN TK-QUICK CHANGE ALUMINUM CALIPERS-USA MADE Super Twin Truck 2-Piston aluminum calipers; Hi-Performance 2-piston direct replacement for GM calipers; Caliper Kit Includes:; (2) Super Twin Truck 54 mm calipers; Banjo Bolts and copper...

ssbc-usa.com

The SSBC caliper's total cylinder area is pivotal; to be effective SSBC's ought to be nearly equivalent (in total cylinder area) to the 80mm or 86mm GMT400 OE cylinders. Yeah, I get it they're dual piston, but if the total piston area was (say) only 70% of the 80mm GMT400 caliper, I would pass.

(Jeg's)

SSBC-USA A186-1: Super Twin Quick Change Front Caliper Kit Late Model GM & Dodge Trucks/SUVs - JEGS

Applications Chevy/GMC Chevrolet Blazer (Fullsize 4WD) (1992 - 1994) Chevrolet Silverado 1500 (2WD) (1988 - 1991) Chevrolet Silverado 1500 (2WD) (1992 - 1998) Chevrolet Silverado 1500 (2WD) (1999 - 1999) Chevrolet Silverado 1500 (4WD) (1988 - 1991) Chevrolet Silverado 1500 (4WD) (1992 - 1998)...

www.jegs.com

Jeg's says SSBC's calipers have dual 54mm pistons. That's the same effective area as the 76mm piston GMT400 calipers (JB5/JB6), and notably less than the 80mm and 86mm calipers.

A97obs · Mar 26, 2024

1998_K1500_Sub said:
As I noted in my earlier post, the NBS MC has a larger piston bore than the JB7 MC, by quite a margin (~40% greater area). Translation: The NBS MC will require more pedal pressure, when compared to the JB7 MC, under similar braking conditions.

Stating it differently: For the same pedal pressure, and all other things being equal, the JB7 MC will (should) provide greater braking effect.

Don't fall in love with the NBS MC. I have the NBS MC, and for me it works well, but if I was doing it all over again I would use the JB7 MC.

Either MC (NBS or JB7) *must* be used with the larger 80mm or 86mm for the reasons I noted... I'll take this opportunity to (re)emphasize this.

1998_K1500_Sub · Mar 27, 2024

Here are a couple p/ns that RockAuto's specs show as being 86mm piston calipers:

NUGEON 9717271A - front right
NUGEON 9717271B - front left

POWER STOP L4347 - front right
POWER STOP L4348 - front left

FYI, for reference, from the factory service manual for 1998 (below).

The caliper sizes aren't mentioned, neither is the MC bore or whether the brakes are "low-drag" / "quick-take-up".

The rear brake information is more illustrative, as is the brake assist method used (vacuum / hydraulic)

You must be registered for see images attach

Further info on c3500 to 1/2 ton Caliper swap from a old thread

A97obs

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1998_K1500_Sub

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A97obs

I'm Awesome

1998_K1500_Sub

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sewlow

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A181 Front Quick Change Caliper Kit (Pair)

A97obs

I'm Awesome

A181 Front Quick Change Caliper Kit (Pair)

1998_K1500_Sub

Nitro Junkie

1998_K1500_Sub

Nitro Junkie

A186-1 Front Quick Change Caliper Upgrade Kit

SSBC-USA A186-1: Super Twin Quick Change Front Caliper Kit Late Model GM & Dodge Trucks/SUVs - JEGS

A97obs

I'm Awesome

1998_K1500_Sub

Nitro Junkie

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