Brake code ID

[Leeztruk]

Trying to ID the brake system on my '89 Cheyenne. The SPID shows a J code of J50. Can this be considered the JB5 system? It's the only J code on the SPID. The vacuum booster is the larger unit. There is no F44 code, so I'm assuming the truck is the light duty variety. Anyway's, I need to improve the braking, as they flat-out Suck !! With LS powertrain, the truck is more lively and responsive, but the braking is just NO match for the added power. Thanks

 

[Caman96]

Is it a 2500?

 

[grampadirt]

Found via search on the 'net:J50 : BRAKE SYSTEM, POWER
another:

J50	BRAKE SYSTEM,VACUUM OR HYDRAULIC POWER(WITHOUT DUAL REAR WHEELS)

 

[xXxPARAGONxXx]

https://rparts-sites.s3.amazonaws.com/dec399b0838336997484042ed2af1004/design/rpoCodes.pdf

You must be registered for see images attach

So, no, it's not JB5. It's probably a predecessor to the JB and JD-series brake system RPO codes. (Major assumption though.)

 

[SNCTMPL]

My son’s 89 has the J50 code and it has the JB3 brake system. The small discs in front and the 10” drums in the rear, also the small mc and booster.

Upgrading everything to JB6.

 

[Leeztruk]

Thanks Paragon. Think it's time to pull a wheel and do some measuring!

 

[Schurkey]

WHAT VEHICLE??? Pickup? Suburban? Something else? C or K? 1500, 2500, or 3500?

JN3 is a strong possibility if this is a regular-cab 1500 pickup truck. JN5 if it's an extended-cab 1500 pickup.

Have you ever bled the RWAL unit? Should have a bleeder screw right on it.

If the rear brakes are the terrible 254mm Leading/Trailing shoe drums, they're almost certainly out of adjustment.

 

[joshwoloshyn]

My son’s 89 has the J50 code and it has the JB3 brake system. The small discs in front and the 10” drums in the rear, also the small mc and booster.

Upgrading everything to JB6.

What did you use to upgrade to JB6? I want to upgrade my 89 c1500 with the J50 code. I have a Ford 9" in the back and it has 11" brakes

 

[GoToGuy]

You must be registered for see images attach

 

[SNCTMPL]

What did you use to upgrade to JB6? I want to upgrade my 89 c1500 with the J50 code. I have a Ford 9" in the back and it has 11" brakes

I went with a Powerstop kit up front, 14b axle with the 11.15” drums and all new ACDelco parts out back. And an 11” Tuffstuff booster with an ACDelco quick take up master cylinder.

You must be registered for see images attach

You must be registered for see images attach

You must be registered for see images attach