I've got an 87 suburban and have located the service parts identification sticker, but it doesnt have the brake codes listed on it. My power brake booster is shot, and the replacement is either stamped JB7 or a JB5. Its got everything listed but the brake code (unless i'm lookin in the wrong place...). if anyone can help me either find where it would be, or decode the vin to figure it out, it would be greatly appreciated.

its an 87 R20 with a 454

 

pic for reference -

 

RPO code Z82 notwithstanding, it has to be JB5 unless someone "upgraded" it along the way. I couldn't find RPO code JB7 (for GVW 8,400 lb) available from the factory on the 1987 R20/2500 Suburban.

 

Dude, thank you... I've been putting off repairing it because I couldnt figure this out for the life of me.

 

Oops, I just double-checked the GVWR on model R20906 and it's 8,600 which means yours came equipped with the JB7 brake package. I was going by what they used to call the model weight. Sorry for the misinformation prior.

 

ahh, i was looking at the pictures and the vaccum hose looked to be in the wrong spot in reference to the master cylinder mounting bolts.

 

Oh, good. I was hoping you'd catch my update before ordering the part.

 

I found the brake code (jb5) on the sticker in my glove box for my 97 chevy 1500.

 

I need help in determining whether, or not, my 1985 Chevy S10 was originally equipped with power brakes, or not? The VIN number does not give this info, and the Service Parts Identification sticker on the glove box does not indicate brake type (I find this odd because it indicates power steering - what about BRAKES !!!!!?). Reason I am wanting to know is because it originally had a 2.5 4cyl. engine and 4 speed manual transmission. It was converted (before I purchased it) to a 305 C.I. V8 and automatic transmission - clutch pedal assembly removed. There are 2 factors that cause me to be curious about this: (1) the brakes don't seem to be operating correctly, but I'm not sure because it's been many years since I drove a vehicle with manual brakes, therefore I don't remember how they are "supposed to feel" - they feel like I really gotta apply pressure to them to work. There is no air in the system, so that is not the problem. (2) I notice on the firewall a somewhat square pattern (dirt film) which looks to me like there once was a brake booster installed(?). So, in lieu of this unknown information, I have to wonder, if the (possible) power brake booster was removed, were the wheel cylinders changed (different bore size)?, was the master cylinder replaced with the proper one?, is the proportioning valve correct? I am leaning toward the probability that the truck came factory with power brakes - mainly because I don't think manual brakes were available on that model year(?) I would like to either keep the manual brakes and be sure to have the correct "other" parts to match, or install a power brake booster. Any help in determining if the truck originally was equipped with, or without power brakes will be greatly appreciated. If preferable, one can contact me via my email address: harveyman@charter.net