• Welcome to The Truck Stop! We see you haven't REGISTERED yet.

    Your truck knowledge is missing!
    • Registration is FREE , all we need is your birthday and email. (We don't share ANY data with ANYONE)
    • We have tons of knowledge here for your diesel truck!
    • Post your own topics and reply to existing threads to help others out!
    • NO ADS! The site is fully functional and ad free!
    CLICK HERE TO REGISTER!

    Problems registering? Click here to contact us!

    Already registered, but need a PASSWORD RESET? CLICK HERE TO RESET YOUR PASSWORD!

Updated tsb proportioning valve

THEFERMANATOR

FRANKENBURBAN
Staff member
Lead Moderator
Messages
10,057
Reaction score
4,317
Location
ZEPHYRHILLS FL
If anybody is needing or thinking about getting one of the updated combination/proportioning valves, then now is the time to get one. I've spent the last 4 weeks looking for one and finally found a couple. GM has discontinued these(or at least the 95+ version), and there's only a handful left in the states. I'm getting one for my 99 because it's rear brakes don't do anything, so it NEEDS one. I ended up going to my local dealer, got them to do a search, printout a list of who says they have them left, and started making phone calls until I found one. It won't be long and they'll be all gone.

Part number for the 95-00 is 12548265.
 

Husker6.5

135' diagonal 16:9HD, 25KW sound!
Messages
2,524
Reaction score
2,684
Location
Lincoln, NE
If anybody is needing or thinking about getting one of the updated combination/proportioning valves, then now is the time to get one. I've spent the last 4 weeks looking for one and finally found a couple. GM has discontinued these(or at least the 95+ version), and there's only a handful left in the states. I'm getting one for my 99 because it's rear brakes don't do anything, so it NEEDS one. I ended up going to my local dealer, got them to do a search, printout a list of who says they have them left, and started making phone calls until I found one. It won't be long and they'll be all gone.

Part number for the 95-00 is 12548265.
What was the cost (so I can prepare for sticker shock, if need be) of the valve?
 

THEFERMANATOR

FRANKENBURBAN
Staff member
Lead Moderator
Messages
10,057
Reaction score
4,317
Location
ZEPHYRHILLS FL
Cost me $203 delivered from Arnold Oil Co. out of Texas. This was the superceded part number for the last combination valve available. It was listed as the oem part for half ton gmt-400' for 99-00. Starting in 2001 GM stopped using this unit and switched everything over to the style that used a separate proportioning valve. I know it made a HUGE difference in my 95 when I put it in. I know I called/ordered from almost a dozen different places before I finally found one. The place I ordered from listed 3, but only had 2 in stock.
 

Husker6.5

135' diagonal 16:9HD, 25KW sound!
Messages
2,524
Reaction score
2,684
Location
Lincoln, NE
That's not nearly as bad as I had imagined it could be, but not as cheap as I hoped it to be. I wonder if my '98 K2500 Burb has the new style proportioning valve in it or the old one. How do I go about telling @THEFERMANATOR ?
 

FellowTraveler

Well-Known Member
Messages
3,716
Reaction score
3,912
Location
Nature Coast
OK, my 1999 Suburban K2500 8.6+ GVWR has no proportioning valve that I can see anywhere inside the engine bay. One line from master go's directly to ABS manifold and the other goes down to the chassis rail.

What now?
 

THEFERMANATOR

FRANKENBURBAN
Staff member
Lead Moderator
Messages
10,057
Reaction score
4,317
Location
ZEPHYRHILLS FL
The valve is in the end of the abs unit where the lines from the master screw in. None of the 2500's got the revised valve. The 1500 6 lugs were supposed to have gotten it, but several had swapped this valve in and seen braking improvements.
 

FellowTraveler

Well-Known Member
Messages
3,716
Reaction score
3,912
Location
Nature Coast
I suspect when going to a disk brake rear I need locate anther ABS unit for the disk conversion, or?

I had asked earlier about installing an adjustable proportional valve thiking I had one of those stand alone types however; do you think it is doable to eliminate the valve in the ABS which only controls the rear brakes anyway and plumb a rear brake adjustable proportion valve, or?
 

THEFERMANATOR

FRANKENBURBAN
Staff member
Lead Moderator
Messages
10,057
Reaction score
4,317
Location
ZEPHYRHILLS FL
It was a technical service bulletin because as many know, the rear brakes on the burbs SUCKED! There's a post here somewhere where they tested the stock valve and found GM capped rear pressure at 600, but started tapering it off alot sooner. The new valve caps rear pressure at 800, but keeps front and rear braking pressure closer for alot longer. The other part of the tsb that applied to all vehicles with the 13x3.5 rear shoes was the new rear shoes with updated friction material. My Burb's brakes were pretty good with just stainless brake lines until I did my swap. After my swap the added weight made stopping scary as it felt like the rears didn't do anything. Replaced the valve and it was a different story, and the rear shoes made it so you could actually feel the rear brakes. Now with the 1 ton drw brakes and 3500hd booster, I can stop if needs be(still kick myself for not going gmt-800 brakes with how often I've had to do my brakes).
 

Husker6.5

135' diagonal 16:9HD, 25KW sound!
Messages
2,524
Reaction score
2,684
Location
Lincoln, NE
So if I call the local stealership (not even the same state the vehicle was previously owned in) with the VIN of my 98 K2500 Burb, should they be able to tell me if it had been replaced with the updated valve under that tsb or not?
 
Top