1987 Dodge Dakota height sensing proportiong valve

I wonder if Dusty or Alxxl are still around to give an update on how their bybass is working?

I tried to work this out about 5 years ago. I talked to mechanics, service managers and engineers and they all said I would be crazy to try it. Glad you figured it out. Now I have no choice because the lines have corroded and split and the valve is a mass of rust.

So help me get this straight:
1. You block off the back port which goes straight (in-line) with the front proportioning valve. How did you do that because that is a wacky looking fitting! (Large nut with small tube opening) Where did you find a plug?
2. Then you run the line which branches off the bottom of that same front proportioning valve and route that back to the Tee on the rear axle.
3. The line that used to come off the rear of the front proportioning valve to the HSPV is completely eliminated.

Is that it? I wonder what that other (bypass?) Line was for?
Hope you guys are out there.

I thought I would add to the success list for anybody researching this problem. I bypassed the height sensing valve just the way it was described by Dusty and Axxl and it seems to work great. Rear wheels locked up a couple of times during a rapid stop when the roads were wet. But all-in-all it was a good way to eliminate this annoying and expensive problem for just a couple of bucks (brake line and brake fluid fluid).
Thanks guys.

Great posts guys. Ends up I have the same problem as well. I have an old 87 Dodge Dakota that I am working to get back on the road. I did the HSPV Bypass and blocked off the return on the main proportional valve. Everything seems to work great and have decent pressure in the brakes but I still have the brake light on my dash. Now is this light on the dash related or is this pointing to another issue. My thing is I am trying to get a NYS Inspection done but need to get the light to go off. Any ideas on what it could be, is it because of the HSPV bypass, or is it something else. What would cause this light to trigger?

[quote="merlin2021"]If it's the red light check the parking brak lever, the switch there may be stuck/defective, or you actually are low on fluid or have a leak still.[/Quote

Yup it's the red brake light on the dash. For the longest time it was the parking brake lever that was messing up. It no has been on constantly. I even tried disconnecting the parking brake sensor wire to see that would get the light to go out and it didn't change anything. Now would doing the HSPV bypass and plugging the return line on the main proportional valve cause the light to go on?

Yes the light was on before I ran the bypass. I bleed both back drums but did not bleed the front and yes the proportional valve does have wires connecting to it at the top. Could the light be going on cause air could be in front half of the system? If I bleed the fronts do I need to bleed the rears again?

Yeah they actually work now. If I jam on the brakes the back can lock up. I'm going to head home and try bleeding the front to see if it is as simple as that.

Well I went to bleed the fronts and the left one bleed fine but the bleeder valve on the right snapped right off. So for now I cant bleed the right one. Either way it didn't turn the light off. I tried doing the reset procedure by holding down the brake pedal with the Ignition turned to AC and that didn't work. In the end I just went to the proportional valve and removed the sensor wire. That turned the light off. Hopefully that will get me through inspection.

As for later I still have an issue, correct me if I am wrong but either the proportional valve/metering sensor is not working correctly and needs to be replaced, air could still be in the system, or I have a short in the sensor wire going to the brake light. Any other ideas on what it is. Also thanks for the advise thus far all good stuff.

No the rear brakes do have good pressure now. Yeah I didn't think about bleeding from the banjo bolt very good point. I'll give the system another full bleed to see if it's still got air in it. For the rear port in the back of the proportional valve the one I blocked was the return. This truck is old and needs alot of work. Heck of a project that I decided to take on haha.

Since I removed the HSPV everything has been fine but I was thinking or replacing or upgrading the main proportioning valve. Does anyone know where I can get one that is compatible with the 1987 Dodge Dakota or would I be able to utilize an aftermarket proportioning valve? I am just airing on the side of caution and would like to pretty much rebuild my brake system in the car.

So basically I can just swap one in that is for a car with front disk and rear drums without a HSPV. Didn't know if you had to get a specfic sized valve or if you could just swap one out. Problem I'm having is the rear plug I am using is leaking ever so slightly. The brakes work but still feel a bit soft just trying to firm them up some more.