Well, we haven't done very many of these...........Now we are informed. Now are you talking about the proportioning valve on the frame under the master cylinder, or are you talking about the splitter on the rear differential?


Trying to figure out what you mean by a "residual pressure valve" and where it is located.

 

In all my hair pulling today...(Research)...I have learned a few of the differences between the various years. My 1998 has a proportioning valve, but the 2003 did not. Either proportioning was handled by the master, or it was incorporated into the ABS system somehow.

One thing I didn't see, or hear mentioned, or even referenced, was a residual pressure valve. I think maybe it's the name of a valve IN the prop valve, or maybe the master...but it isn't any of the junctions either at the frame or on the rear end.

 

It's a simple issue, but in no ways am i being responsible and explaining the process so people can "Try something"
10 to 2 psi

 

hmmm could you swap in the brake system from a 03? the master cylinder and what not?

 

Normally I would say yes, but it would involve swapping all of the ABS stuff, which not only would be very difficult but also very expensive.

 

srch<---read the thread. Yes is the answer but we are having complications.

Duranged<-- Are you drunk again?


Now these swaps have been done without issues, so my question is, why the hell is there all of a sudden and issue?

COMBINATION VALVE
The combination valve contains a pressure differential
valve and switch and a proportioning valve.
The combination valve/proportioning valve are not
repairable and must be replaced as an assembly.

PRESSURE DIFFERENTIAL SWITCH
The pressure differential switch is connected to the
brake warning lamp. The switch is triggered by
movement of the switch valve. The purpose of the
switch is to monitor fluid pressure in the separate
front/rear brake hydraulic circuits.
A decrease or loss of fluid pressure in either
hydraulic circuit will cause the switch valve to shuttle
forward or rearward in response to the pressure
differential. Movement of the switch valve will push
the switch plunger upward. This closes the switch
internal contacts completing the electrical circuit to
the warning lamp. The switch valve may remain in
an actuated position until repair restores system
pressures to normal levels.
PROPORTIONING VALVE

The proportioning valve is used to balance frontrear
brake action at high decelerations. The valve
allows normal fluid pressure during moderate braking.
The valve only controls fluid pressure during
high decelerations brake stops, when a percentage of
rear weight is transferred to the front wheels.

 

its basic automotive theory I learned in grade 10 mechanics, 12-13 years ago.

don't touch the splitter on the rear axle, its just that a splitter.

possible its part of the proportioning valve. actually the prop valve needs to be changed anyway, different bias when you have rear discs. on my honda civic if I swapped in rear discs the proportioning valve is a little box on the firewall that has the front and rear brake lines come in from the master then comes out to front and rear brakes. it looks like a distribution block.

didn't get a chance to look for it under my durango tonight. if you havn't figured it out in the next day or so i'll be able to look this weekend to figure it out.

 

hydra i did read the thread. i didn't know what all would be involved. thats just what popped into my head was to try swapping the whole system. i didn't think about the abs system. mine just has rear abs so idk. i see you are having complications lol. locking up of the brakes would be a serious complication. maybe firepro will chime in soon. i see he has a leaky master cylender so maybe its all in the pressure from the master cylender or something like that.

 

Not to hijack the thread but was 2003 the only year for disc brakes? What model were they on Dakota and durangos? I know on my 99 Durango the is a straight brake line that runs from the master cylinder block to the rear rubber hose splitter box. I had to replace that brake lone that feeds the rear axle. Napa wanted 150 for it. I said nope and bought. Standard brake line and a tubing bender it took 2 6 foot peices. There was nothing on my frame rails.I seen some where u can buy a proportioning vavle to adjust rear brakes maybe u can add one of those inline to lower the pressure.

 

The shop that installed my gears and axle swap said they would need to install a proportional valve that could be adjusted. He said they would adjust the amount of fluid between the front and rear discs.

I will swing by there today and talk to him to see exactly what this method is and where this part comes from. I have not had it put on mine, as I have not had Soopers problems. Not sure yet that when I change my booster out if I will have them.

Pic of valves I just took.