OBS to NBS MC upgrade questions

[Conspiracy]

Was there any issue before you messed with your JD7 brakes?

No real “issue” to speak of aside from what seems to me to be less than great stopping. Again, I’ve never had a 2500. I’ve had one other suburban but it was a 2001 1500 5.3l so an entirely different feel. All my other cars have been cars or minivans.

I tow with this one mostly and I just want to feel safe for when people pull at in front of me at intersections or when I’m close to a light being red.

 

[Keeper]

Have you adjusted the rears?

 

[Caman96]

No real “issue” to speak of aside from what seems to me to be less than great stopping. Again, I’ve never had a 2500. I’ve had one other suburban but it was a 2001 1500 5.3l so an entirely different feel. All my other cars have been cars or minivans.

I tow with this one mostly and I just want to feel safe for when people pull at in front of me at intersections or when I’m close to a light being red.

I’m thinking a properly maintained/setup JD7 brakes would be fine.

 

[termite]

I'll echo Keeper and others. Ensure the rears are adjusted and in good order. Flush/bleed all 4 corners to clean fluid and inspect everything else. Stock JD7 set up should be plenty for the rig.

My 1995 k2500 Suburban with JD7 will put you in the windshield if you stab the brakes. (Previously the right hand ditch, but that was a sticky caliper piston in need of polish).

 

[Schurkey]

1. How many other Hydroboost vehicles have you driven? My K2500 with JD7 brakes is the only vehicle I have real seat-time in; and the brake "feel" is totally-different from all the vacuum booster vehicles I've driven.

2. Wouldn't surprise me that the ABS has NEVER been bled since the truck was built. A fluid flush including bleeding the ABS is strongly recommended.

3. Sticky calipers--guide pins not appropriately lubed, pistons stiff in the bores--are very common. If the pistons seize, braking is severely affected. But if they're merely "stiff", brake feel is goofy, non-linear. If one caliper is stiff, there may be a "pull" but if both are stiff, it'll stop straight, but feel weird.

 

[Supercharged111]

Any of these trucks, properly maintained with hydroboost, should have no trouble putting you through the windshield at 80. In the event it won't, as is the case with my plow truck, basic maintenance is in order. The NBS master cylinder only kinda sorta masks the never-adjusted-correctly POS 10" rear drums. There's absolutely positively no reason for it, and no benefit to it in this application. Your HB center bore is smaller than the OD on the NBS MC so it's not gonna fit without grinding.

 

[Conspiracy]

Since there were quite a few replies - I'll just answer generally.

I don't know if the 2001 1500 Suburban had hydroboost but it stopped more like a minivan.

This feels like I'm trying to stop a train, especially when pulling the boat. I'd have to STAND on the pedal to come to a quick stop. It sure doesn't feel like anything would "put me through the windshield"

I've done exactly zero brake maintenance since buying this truck approx 18 months ago. I did put power steering fluid in the reservoir once after hearing it might improve braking.

With this upcoming brake replacement - I'm expecting the rears will be adjusted along with shoes replaced. I got new hardware kit as well. I don't know what needs to be done regarding a reproportioning valve - I might have to order a new one though?
New brakes will be new rotors and pads. I didn't think to replace calipers.

 

[Caman96]

This feels like I'm trying to stop a train

Likely the symptom of a brake system needing attention.

 

[Keeper]

Both of your suburbans have/had hydroboost. Your '01 suburban had disc brakes in back. Your 99 has rear drums, and they require periodic adjustment. If you're not doing them yourself, make sure and get them tightened up whenever it's in for any other service, like oil changes or whatever. It's important, especially when towing.

edit: also have them, or you, make sure there are no leaks in the back from an axle seal or wheel cylinder. A drum can hide a leak. Make sure to take the drum off, just doing an adjustment does not require it to come off.

 

[termite]

pulling the boat.

One other point to check, I'm assuming this is a decent sized boat on a trailer with surge brakes and not a light jon boat. Maintenance on your trailer brakes as necessary as well. (Obviously disregard this point if it is a trailer without brakes)