JB7 Brakes with NBS master cylinder to stop spongy brakes?

obssuburban · Jun 15, 2024

I recently posted a thread saying that my brakes on my C1500 Suburban are horrible after the nbs upgrade(spongy and hardly any braking power) . I got a lot of recommendation to go back to OEM, but as I dug deeper I saw if i swapped my current JB6 brakes for a JB7 non low drag caliper and rear jb8 wheel cylinder its should make my brakes a lot better. I am willing to go back to the OEM JB6 master as long as my brakes work but they were bad too when driving, they would stop but not very fast. I really do not want to buy another master cylinder though as i have a almost ew OEM one and new NBS one as well, and think there is a way to stop the brakes from being so spongy with these two products. The two part numbers I got from another forum indicate part ACDELCO 18R741 and ACDELCO 18FR741 along with ACDELCO 18E1362. Thank yall and sorry for the non expertise lol. I plan on knowing these trucks inside and out by the time I get mine cleaned up.

Boots97 · Jun 15, 2024

Combining NBS and OBS brake parts are not ideal. Sell off your JB6 mc and NBS mc and buy yourself a JB7/JB8 mc and get JB7 front calipers and JB8 wheel cylinders. I did this and it made my braking more aggressive and positive then with the original JB6 brakes I had.

Don'y use a JB6 mc with JB7/JB8 stuff. I had a JB6 mc with JB7/JB8 stuff for a few days and I had to floor the brakes to get the truck to stop.

If you REALLY don't want to spend any more money, keep the NBS mc and use JB7/JB8 stuff with it. NBS master cylinders are single chamber just like JB7/JB8 master cylinders and therefore will work with each other. JB6 master cylinders are multi chambered so they won't work with anything single chamber related.

GoToGuy · Jun 15, 2024

Keep in mind, it's a heavy vehicle. You can improve stopping, but don't expect miracles, unless you wanna spend thousands. Use good drums and rotors and higher end option or pads and shoes. At work I went for the top of line car quest rotors, drums, pads, shoes. New rear wheel cylinders. And it did make a big difference. But it's still a big heavy vehicle.
Caution, it's less hassle , headache, grief if you use parts from the same class, series, rather than reinventing the wheel. 1500, 2500, 2500 HD, All the combinations have already been tried. Some work done don't. Often those who say " this works " have left out important small details that determine which trucks will or will not work on. Good luck.

Schurkey · Jun 16, 2024

Why start another thread on the same topic?

obssuburban · Jun 29, 2024

Boots97 said:
Combining NBS and OBS brake parts are not ideal. Sell off your JB6 mc and NBS mc and buy yourself a JB7/JB8 mc and get JB7 front calipers and JB8 wheel cylinders. I did this and it made my braking more aggressive and positive then with the original JB6 brakes I had.

Don'y use a JB6 mc with JB7/JB8 stuff. I had a JB6 mc with JB7/JB8 stuff for a few days and I had to floor the brakes to get the truck to stop.

If you REALLY don't want to spend any more money, keep the NBS mc and use JB7/JB8 stuff with it. NBS master cylinders are single chamber just like JB7/JB8 master cylinders and therefore will work with each other. JB6 master cylinders are multi chambered so they won't work with anything single chamber related.

Do you have links to the parts, I dont want to buy the wrong part lol

Boots97 · Jul 29, 2024

JB7 Master Cylinder
ACDELCO 18M712

JB7 Front Calipers
BrakeBest Disc Brake Caliper - Remanufactured - 18-4298
BrakeBest Disc Brake Caliper - Remanufactured - 18-4297

JB8 Wheel Cylinders
BrakeBest Wheel Cylinder - WC79768

You can keep your old pads/shoes depending on how good of condition they're in. If you want to replace the pads and shoes, I'd go with Raybestos EHT369H for the pads and Raybestos 473PG for the shoes.

HawkDsl · Jul 29, 2024

Boots97 said:
<Snip>

You can keep your old pads/shoes depending on how good of condition they're in. If you want to replace the pads and shoes, I'd go with Raybestos EHT369H for the pads and Raybestos 473PG for the shoes.

Raybestos is making really good quality stuff these days. Agree 100%.

REM777 · Aug 24, 2024

HawkDsl said:
Raybestos is making really good quality stuff these days. Agree 100%.

Have always bought Raybestos from Rockauto - they are a distributor and usually give a great price - however raybestos was bought out the asbestos law suits killed them - Imy brake issue came about from installing a new set of pads - this time I tried the powerstop Z36 - heard great things about them - wanted to try the Z39 but they werent available in my caliper size

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df2x4 · Aug 24, 2024

REM777 said:
however raybestos was bought out the asbestos law suits killed them

Curious about your source for this information. I see that the company has changed hands a couple times since around 2014, but in my experience they're still making good stuff. It's been confirmed that they are a current supplier for many OEM GM brake parts and I'm running their EHT369H pads on both of my '97s with great results.

Side note, those PowerStop Z36-369 pads you posted have a friction code of FG, visible in the first picture of the Amazon reviews. The Raybestos EHT369H are about $10 cheaper per set on RockAuto, and are rated HH. More info can be found if you do a search for "DOT friction/edge codes" but long story short, the farther along those two letters get in the alphabet, the more aggressive the pad material is.

Schurkey · Aug 24, 2024

df2x4 said:
More info can be found if you do a search for "DOT friction/edge codes" but long story short, the farther along those two letters get in the alphabet, the more aggressive the pad material is.

First letter = cold friction coefficient; second letter = hot friction coefficient.

JB7 Brakes with NBS master cylinder to stop spongy brakes?

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