Question about brake options - The 1947 - Present Chevrolet & GMC Truck Message Board Network

beaterC10 · 08-20-2003, 01:33 PM

Can anyone shed some light on the different brake options?
I know the obvious, power and manual

, but is there a difference in the rear brakes?

I ran into this while rounding up the parts to put drop spindles on my truck. I have the 1" rotors on my truck now and the spindles I found require the 1.25" rotors. During my search for parts I noticed a reference to JB3 and I think JB5 power brake options. I was wondering if the larger front rotors were used with larger shoes in the rear or higher capacity wheel cylinders.

Would there be any benefit to finding larger rear brakes (if they exist) for a short stepside 1/2 ton?

**swervin ervin** · 08-20-2003, 06:01 PM

JB3 is 11.86 x 1.04 discs up front and 11 x 2 shoes at the rear.

JB5 is 11.86 x 1.28 discs and 11.15 x 2.75 shoes.

JB5 brakes do exist because this is what I have on my truck. I'm not sure what all would be involved in swapping out the rear brakes. Probably everything from backing plate out.

beaterC10 · 08-20-2003, 10:08 PM

Thanks. Does the option sticker in your truck list the JB5 brake option? I would asssume it was an extra cost option over the JB3.

08-20-2003, 01:33 PM	#1
beaterC10 Senior Member Join Date: Jul 2003 Location: Indianapolis, IN Posts: 1,277	Question about brake options Can anyone shed some light on the different brake options? I know the obvious, power and manual , but is there a difference in the rear brakes? I ran into this while rounding up the parts to put drop spindles on my truck. I have the 1" rotors on my truck now and the spindles I found require the 1.25" rotors. During my search for parts I noticed a reference to JB3 and I think JB5 power brake options. I was wondering if the larger front rotors were used with larger shoes in the rear or higher capacity wheel cylinders. Would there be any benefit to finding larger rear brakes (if they exist) for a short stepside 1/2 ton?

08-20-2003, 06:01 PM	#2
swervin ervin You get what you pay for Join Date: Dec 1999 Location: Cherryville, NC Posts: 4,798	JB3 is 11.86 x 1.04 discs up front and 11 x 2 shoes at the rear. JB5 is 11.86 x 1.28 discs and 11.15 x 2.75 shoes. JB5 brakes do exist because this is what I have on my truck. I'm not sure what all would be involved in swapping out the rear brakes. Probably everything from backing plate out. __________________ Mike 1985 Chevy C-10

08-20-2003, 10:08 PM	#3
beaterC10 Senior Member Join Date: Jul 2003 Location: Indianapolis, IN Posts: 1,277	Thanks. Does the option sticker in your truck list the JB5 brake option? I would asssume it was an extra cost option over the JB3.



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