Hey guys, doing a restoration on my 1994 extended cab, step side. I have installed the nbs master cylinder, as at one time, that seemed to be what would help with the soft petal on these trucks. Reading through the forums, I see various opinions, on how these brakes should be setup. Should I stay with the original master cylinder, or stay with the nbs master cylinder? Also, what other upgrades should I do, to the brakes? Will updating the drums, on the rear to disk, allow the new nbs master cylinder, to work properly. Just want to upgrade the brake system, to what will work properly.Thanks
What
rear brakes do you have already? Do you
already have JB6 or
considering a JB6 upgrade from JB5 (to 11" drums)?
I know the quick-take-up / low-drag systems
can work reasonably well, but on account of the uncertainty of the JB5/JB6 replacement calipers out there (are they really built for low-drag or aren't they? See attached.) I prefer to side-step the entire matter and use the "regular" brakes that came on the JB7/JB8. Too, the JB6 brakes on my Suburban never worked well, so I'm jaded.
The NBS MC is a non-quick-take-up design, as are the GMT400 JB7/JB8 MCs.
The JB7/JB8 calipers are a non-low-drag design, appropriate for the non-quick-take-up MCs.
Although the NBS has a larger bore (~1.34"/34mm) than the typical JB7/JB8 (1.25" for HD / 1.125" for vacuum boost, I believe) and thus
seemingly puts you at a bit of a disadvantage, the JB7/JB8 calipers with their larger bore (3.15"/80mm and 3.385"/86mm bores are available) will offset the disadvantage almost completely, relative to the stock JB6 caliper (3"/76mm).
I've got the NBS MC on my K1500 Suburban, 3.15" JB7 calipers in front (vs. 3" OE) and 1.1875" slave cylinders in the back (vs. 1" OE) on 11" OE drums. The Suburban weighs about 6200# across the scales almost evenly distributed F/R. The brakes work very well IMHO, MUCH better than they ever did for as long as I've had it; the brake pedal moves without any resistance until the brakes engage and then it's VERY firm, and the brakes very responsive IMHO (perhaps not like a BMW, that's a different class of machine). I've SS hoses F/R as well, which contributes to the firm pedal.
Since you have the NBS master, I would not encourage you to replace it. If you were starting from scratch, I would suggest the GMT400 non-quick-take up MC used on the heavier trucks.
I made some comments about the rear disc setups elsewhere in some recent threads; I'll post a link. Different people view them differently.
(edit) See
My truck is a 96’ GMC Yukon, 5.7 vortec, K1500, 2 Door, lifted on 35x12.50 tires, with factory JB5 brakes, 6 lug 10 bolt rear. I’m looking for help identifying what models to pick the backer plates, and drums from to go from the 10” leading/trailing JB5 rear drums to the 11.x JB6. I’ve read...
www.gmt400.com
and
Hi Everyone, I fully rebuilt my front and rear brakes on my 1997 Chevrolet K1500 Z71. I installed 2500 calipers with Raybestos Element 3 pads and installed 3500 dually wheel cylinders with Raybestos 473PG shoes and Brake Best hardware kit. I bled the brakes all around 3 times and overall am...
www.gmt400.com
This one is good too:
I stumbled upon this discussion about the GM low-drag calipers on the JalopyJournal website. I know most on GMT400 understand the low-drag calipers and their corresponding quick-take-up master cylinders, but for everyone this may be interesting and possibly useful reading. The various posts...
www.gmt400.com