thegawd
I'm Done!
- Joined
- Feb 29, 2020
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I'm sorry my burb is actually JB6 I was going off of memory and I was wrong.
I dont know the awnser though....
I dont know the awnser though....
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Look on your door jamb (if it's still there). My C1500 is 5600#I think mine says 6600 or 6400.
JB/JN3 has vented front rotors, but they're thinner than JB5/6 front rotors. Same diameter, different thickness. The JB3 calipers have smaller pistons, the JB3 master has a 1" regular bore and a 34mm (?) step-bore. The JB3 booster is small-diameter, single-diaphragm "pancake" booster.The easy way to identify JB3 brakes is the front rotor is solid not vented. It was also identified as JN3 in the service manuals.
^^^ This is a BIG DEAL! JB/JD 3, 5, 6. VERY IMPORTANT when selecting a master cylinder. Low-drag calipers are engineered to retract the piston farther than regular calipers. The pads don't rub on the rotors like regular calipers, so the wheels are easier to turn when the brakes aren't applied = better fuel economy, reduced emissions.notice theres conventional calipers and low drag calipers... that's another reason that these rpo codes are important... see that thread to learn the differences....
As said, JB3 has vented rotors also. JB3 was only used in the first few years of GMT400 production. GM wised-up after '91--'92, something like that. Beyond that, yes, converting from JB5 to JB6 is just a matter of throwing away the leading/trailing rear brakes in favor of the 11.x Duo-Servo rear drums--the front brakes are the same between the two. There may be a difference in the combination valve also--but I don't notice any problems with my JB5 system using the JB6 rear brakes.Good stuff! I have vented front rotors, so it looks like I have JB5 brakes, and all I need for JB6 is to replace the rear drum assemblies!
I'm considering doing the same setup - Cunningham conversion, ABS delete. I'm curious how yours has worked out, if you've done it already. I'm also considering NBS/hydroboost swap, if needed after.My truck has JB5 and my brakes suck. I plan on doing the ABS delete with an adj prop valve and Cunningham Machine RR disc setup. More so for ease of maintnence. I do believe my booster/ master is failing and the front hoses need replaced anyway so I will replace the front and rear hoses at the same time.
I have not done it yet and may not. My wheel setup may not clear the caliper.I'm considering doing the same setup - Cunningham conversion, ABS delete. I'm curious how yours has worked out, if you've done it already. I'm also considering NBS/hydroboost swap, if needed after.
My Little Shop Kit Cleared My 15" Rally Wheels With No Problem.I have not done it yet and may not. My wheel setup may not clear the caliper.