2nd Gen Non-Engine/Transmission Height sensing valve

[Bseg]

I read about the height sensing valve that controls the fluid to the rear brakes. This is probably one of the problems with my rear brakes not functioning like they should.



Can someone tell me how to remove the link? Does it just snap off?



Once I remove the link do I want to raise the actuator lever?



http://dodgeram.info/tsb/1998/05-04-98.htm

 

[RonaldLarson]

Maybe

Our old Subhuman had crappy brakes, until I adjusted the rear proportioning valve. Amazing difference. I don't know if our trucks valves are adjustable, but try it. Other than that, you can adjust the rear brakes. Your signature doesn't show what year you own, so if you have rear discs, that won't work. You can also help braking on shoe brake rears by using the parking brake often. That adjusts the shoes.

Ron

 

[RonaldLarson]

Sorry

Your sig has your year of truck. It's early here, duh!

Ron

 

[C. Harlan]

I have looked for mine numerous times, and still to this day, swear I do not have one... I have followed the brake lines all the way down the frame, and still, NOTHING... Maybe I am just not looking hard enough, but I am tired of constantly going through front brakes!



-Chris-

 

[Bseg]

I was able to figure out how to remove the linkage rod last night, it actually just snaps on to a ball joint.



I lifted the lever up a few inches higher and wired it to stay in place, what a big difference in my braking. Oo. The truck stops twice as good now and the antilock still kicks in upon a panic brake. No more stress for the front discs!



What gets me is that my 97 shop manual has no mention of this rear load sensing valve being in the truck. As far as the manual is concerned it doesn't exist. I have tried everything since I bought the truck new to try and take some load off of the front brakes and was to the point that I figured there wasn't much I could do about it.



I only stumbled across this TSB because I was searching through pages about brakes on the TDR just to see how many other people felt like I do about how fast the fronts wear out.



I was convinced that my rear brakes weren't doing anything but couldn't figure out why. I have the larger rear wheel cylinders and adjusted the rear shoes but they still didn't do their job.



I am going to put in the bypass hose that the TSB calls out. If the brakes get too sensitive I will make an adjustable link or some sort of plate that I can adjust the valve with.



BTW, some people are concerned about the fact that the TSB states you must be using at least 75% of the GVWR (8800 lbs. ), like someone else posted, my truck weighs 6700 lbs, 6600 is 75% of 8800, I also have the Rancho shocks which lifted my truck about 1" or so and the TSB says that altered height will affect the valve.



Chris, it's located right above the axle just behind the drivers side wheel. There is a rubber hose that connects to a tee at the axle housing, follow the hose back up towards the bottom of the bed and you should see a little mechanism with a rod that connects down below the axle. Some trucks don't have it, if you have a 96-98 2500 4x4 with Cummins and it is 8800 GVWR more than likely you have it. Let me know if you can't find it, I have a diagram that shows it real clear.

 

[RonaldLarson]

Bseg has it.

I was going to tell Chris what you told him. The difference in braking is amazing, but be very careful on wet or iced roads. The rear end will wave as it passes you. The old subhuman had a splined attachment on the valve, which meant I could adjust it in small increments. I haven't tweaked mine yet, but this thread has me interested again. Mine stops well, and no unusual front brake wear at all.

Ron

 

[Bseg]

Ron,



I got a chance to try mine out in the rain today, so far it's not too bad. I agree it could lock up real easy, no point in finding out the hard way. Seems the anti lock is helping prevent that but at the same time I don't trust the anti lock cause they have locked on me before, on dry and wet pavement.



I ordered the hose from the dealer, it's around $27 so I should be able to put it in soon and I will report back on any changes. If the braking is too strong I will take it out and figure out how to make an adjustable system that can be dialed in.

 

[Little Bill]

I disconnected and wire my linkage up about 4 years ago. Rear brakes were touchy for a couple days until the drums and shoes broke in. Just recently replaced the front pads at 60000, still had more than 50% of pad left.

 

[Bseg]

Got my hose today from the dealer. What is really interesting is I checked with Napa to see what they had, it's the exact same hose that I got from the dealer to bypass the valve. They don't even list a hose that would work with the valve. And it was $4 cheaper at the dealer, that's a first.



A friend of mine found the info about the height sensing valve in is 2001 shop manual, it says it's only on used on the 2500 series with rear wheel antilock brakes. According to him the 3500 doesn't use it.



Since it's not in the shop manual and the TSB says to take it out it sounds like Dodge put something in that just cost more $. Oh well, I can't wait to see if I can get some good mileage out of the front pads now, and better yet, eventually I'll change the rotors again to see how they hold up. This will tell if it's made a big difference besides the rears grabbing well.

 

[dresslered]

3500's don't need no stinkin' height sensing valve!

77,000-miles on original brakes and I have never adjusted the rears. Stops great.

 

[Regcabguy]

I installed the oversized wheel cylinders to no avail. Only the bypass hose finally increased my stopping power. No problems here in SoCal with rear lockup with or without the camper but offroad they will lockup. Panic stops are still hairy on this rig so I engage the e brake on the freeway. You'll feel a major difference!

 

[EBansberg]

I was going to try and adjust mine. Can I just remove the bolt or something and adjust it on a splined shaft. I assumed that is how it was designed but haven't pulled it apart to play yet. After seeing this thread I figured someone would know.

 

[pwerwagn]

Im going to take out the factory "rod" that goes from the axle to the valve, then use a small turnbuckle for adjustment on mine.

 

[98rammer]

i lengthened the rod about an inch so i get more brake pedal pressure, but the rear tires don't lock up under hard braking and try to pass me.



Tom

 

[dresslered]

While trying to help Brad with his problem, I searched the 2001 shop manual, and it seems to imply (at least on the newer trucks) that there are only two positions for the valve (full braking or a reduced setting). I was all for making the valve adjustable, but if only two-positions is true, I would probably just go with the bypass hose. There is also a spring mechanism which is suppose to keep the valve in "set position" in case a bump is encountered during hard braking. This complexity just makes me think that you should just remove the entire contraption. Also, why is it that the 3500's don't ever get a Height Sensing Valve?

 

[Bseg]

Installed the hose yesterday, the brakes seem to work about the same as when I had the valve tied up. Time to keep my eyes on front pad wear.

 

[Eric_77]

What years was this used on? I craweled under the 96 to yank this rod out but I don't see it. Where if the 96 did have one is it located on axle adn what does it connect to?

 

[dresslered]

Not sure of the years that they were used, but aparently, they are only used on the 2500 with rear anti-lock brakes. Here's a pic:

 

[98rammer]

What years was this used on? I craweled under the 96 to yank this rod out but I don't see it. Where if the 96 did have one is it located on axle adn what does it connect to?

i have a complete rear axle (dana 70) from a 96 gasser in my 98. it did not have the adaptor plate for the compensating valve. i don't know if the diesel would or not.

 

[Kirwin]

TSB has specific build dates for applicability

Check out the TSB. It tells what dates this thing was installed.