proportioning valve how to know if its properly adjusted ok

I have a 1999 2wd regular (low) suspension 5 lug 14" tires ext cab sr5 with 2.4L engine with 120k miles and im trying to give the new to me truck all the needed maint I can think of.

I have no pressure gages and basic hand tools and socket set at best so no mechanic specialty tools available here.



I just removed a 3" drop spacer from under the axle that the previous owner had installed so I was literally bottomed out flat to the bump stops and im very unsure how to now "restore" things to work as intended with all 4 brakes.

now im sure he didn't readjust anything (a 16 yr old kid isn't the type you expect to know he needs to readjust things) but im guessing it had to have at least been bent by the truck being dropped 3", or at least that is what I am "assuming". the truck was driven like that as a daily driver for 9 months.

everything under the truck is in really good shape except the rubber boot in the picture above is split at the compression rings which I assume is nothing to care about so I really don't want to replace it with a manual valve or do a shade tree solution to eliminate the stock valve. (in another thread I figured out the stock setup aint so bad). there are no leaks anywhere so im sure the positioning valve is ok and it just needs things adjusted.

I think I might be beyond a "normal" routine adjustment since this thing was dropped almost to the ground (spring bolt ends were even bent from bottoming out on the road) so how do I now try to "reset" things back to stock condition?

also is the crossover rod partially shown in the picture supposed to be perfectly straight or have a bend to it to match the axle hump because mine is bent in an arch shape?

 

I just replaced mine with a used one, my original rusted out and broke inside the upper boot. The plunger/cylinder was also frozen in place. Both the original and the replacement had an arch in the arm. I wouldn't say they matched though. I am also looking for some method to test the adjustment. I know when mine was busted off, a quick and moderately hard stab at the brakes would lock the rear. I interpreted this as too much rear pressure... I think I got that much right. Since my replacement, which shortly followed new and stiffer rear leaf installation, I have no idea where the adjustment should be. I am not locking the rear brakes now though.

Wish I could be more helpful.

 

I saw a post where a guy set it by the service manual pressures (1000 lbs. in the front and only 400 lbs. in back) and after that he jacked up the back wheels off the ground by putting stands under the axle to simulate being on the ground to test it and even standing on the brakes the back tires would still barely roll and one "almost" stopped when he had it in gear.

he figured he didn't do it right so he went to the dealer to have them set it and after charging huge $$$ to check it, they told him it was set perfectly just the way it was.

after reading this I don't think "going by the service manual" or having the dealer adjust it would get me proper rear brakes. I want 60% front and 40% rear brakes when empty unloaded but not 95% front and only 5% rear as the factory settings seam to be.

I suppose having the dealer set it would give me a good starting point to go by to set it myself because I want "some" rear brakes in an empty truck but factory recommended settings are no rear brakes at all until you put a load in it.

I have decided not to mess with what works and keep the proportioning valve setup because I can see where load sensing is better then a manual "fixed" setting where rear may slide around on you but I don't see how either way gives me 4 wheel semi equal braking.

I guess I will just have to go buy two pressure gages, otherwise its just go find a gravel parking lot or grass field and see if its slides straight when I lock brakes in a turn or if the back swings around.

do I just screw the gages onto the bleed screws on the brakes and which brakes do I put them on? farthest from MC or closest?

at least with the pressure gage I can choose the number its set at

 

I'm pretty sure the only part that affects the brake adjustment is the line coming out of the proportioning valve itself. Ive seen a few applications where they literally cut the whole arm off and just zip tied the little stub coming out of the proportioning valve in the proper location. Although i do not know the proper location for it to be zip tied at.

 

This: http://4crawler.com/4x4/4R_suspension.shtml#ProportioningValve

 

yes, and I gave that option some serious thought both ways and finally decided since I was going to use my truck as a truck and haul stuff at times, I better keep the stock valve the way it is and just get it set right. hench this thread.

im sure a manual or fixed valve works for some but this will be strictly a pavement princess so I need the variable component of it. maybe if a abs unit from another vehicle can be used, that would be great, but I need something to prevent rear lockups and the danger of a spin around in hard breaking. I just need to make sure I have "some" rear brakes when unloaded.

I will get two pressure gages and set it at factory specs 1000/400 then if im not happy i'll try 1000/500 and see how it is

 

My lpsv was leaking like a sieve,,, circled that thing like a vulture trying to figure out what I was going to do, junk yard or a new one,, decided to pull it apart and look at the innards, it is a simple valve in function and I decided to clean it up and see what happens, works fine for about the last three months.

I'm like you in the setting part, I set it to factory specs according to the FSM and it seems to be fine, but,,, I haven't refined it which I will by trial and error, hopefully.