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Another proportioning valve question


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ive got a 91 2wd 4.0, long bed, and i was wondering if someone could send me some pictures of how the proportion valve is supposed to look. ive read that its supposed to be paralell with the axle, but the way mine is, i don't know how it could be. as of now its pointing straight at the ground. Also while I'm here, is there a way to shut the matinence req'd light off? THANKS

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Was just going to answer you but Jim beat me to my own thread! :cheers: As to the MAINT REQ dash indicator light, it's triggered by the ECU when the odo passes a certain mileage, and they can be reset by the dealer for a fee. But I just pulled the indicator bulb in my 91 years ago.

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The maint light might be from the maint timer for the oxygen sensor (not sure if they still had them in 91 tho). It is a small clear type box under the dash to the right of the steering column, just disconnect it. They can't be reset

 

Here's a link about the maint timer.

 

http://library.motoralldata.com/techRef ... /Jeep.html

 

Also, I got this from another search. Would be interesting if this truely works.

 

I did it myself, i just found the Emissions Maintenance Timer in my Jeep Wrangler 1991, Its a clear brownish box with small plastics gears on the inside "like a clock" its factory set it for 2750 hrs. you just need to look at that box in the back and remove the sticker to gain access to a small opening where is the activated switch , and with a small screwdriver move that switch from the top of that small gear to the border of the gear where its a guide for the switch. disconect the + terminal from the battery and touch the negative terminal with it the reconect the + terminal and thats it.

 

:cheers:

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:hijack: how important is it to have the proportioning valve hooked up? :roll: cause mine isnt :oops:

How important it is depends on what position it's in when it's NOT connected.

 

What that thing does is to limit (reduce) the amount of braking pressure that goes to the rear wheels when the pickup bed is unloaded, because when the back end is light it's easy to lock up the rear wheels and spin out. As you add weight in the bed, the bed squats down on the suspension, which has the effect of the rod from the differential pushing up the arm of the valve to allow more braking ... which you need with more weight in the truck.

 

If it's disconnected, it might be in the position that allows full braking force to the rear ... in which case you'll have great brakes but you'll have to watch out for lockup and spinout. Or it could be in the position that allows NO braking to the rear -- in which case you will be doing ALL your driving using front brakes only. Your stopping distances will be increased over what they should be, you'll use up front pads rather quickly ... but your rear brake shoes will last (literally) forever.

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:hijack: how important is it to have the proportioning valve hooked up? :roll: cause mine isnt :oops:

How important it is depends on what position it's in when it's NOT connected.

 

What that thing does is to limit (reduce) the amount of braking pressure that goes to the rear wheels when the pickup bed is unloaded, because when the back end is light it's easy to lock up the rear wheels and spin out. As you add weight in the bed, the bed squats down on the suspension, which has the effect of the rod from the differential pushing up the arm of the valve to allow more braking ... which you need with more weight in the truck.

 

If it's disconnected, it might be in the position that allows full braking force to the rear ... in which case you'll have great brakes but you'll have to watch out for lockup and spinout. Or it could be in the position that allows NO braking to the rear -- in which case you will be doing ALL your driving using front brakes only. Your stopping distances will be increased over what they should be, you'll use up front pads rather quickly ... but your rear brake shoes will last (literally) forever.

which position does it need to be in to be putting full braking power to the rear wheels?

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which position does it need to be in to be putting full braking power to the rear wheels?

I will not even attempt to provide a definitive answer to this. You can think about it -- the "normal" position is horizontal, so if the bed drops when loaded, the arm gets pushed up. How much for full braking? I don't have a clue.

 

Further, as far as I am concerned once the link has been removed ... all bets are off. The factory service manual procedure for adjusting it calls for a special gauge, and there's a spring or something (sorry, I'm going from memory here, not reading the book) that has to be replaced EACH TIME an adjustment is made. If the arm on yours is hanging loose, you have no way of knowing if it has been rotated clockwise, counterclockwise, one time or three times, or whatever.

 

The height sensing valve in my '88 blew out when I had to make a panic stop two or three years ago. After experiencing that, I do not trust them. They are all +/- 20 years old at this point. There's no way to test them for integrity, and you can't buy a new one. My suggestion is to eliminate it completely, run ONE new steel line from the front to the rear of the truck and connect directly into the rear flex hose. That gives you 100% rear brakes all the time.

 

If that's too much, then you can put a Wilwood adjustable proportioning valve into the steel line to the rear.

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which position does it need to be in to be putting full braking power to the rear wheels?

I will not even attempt to provide a definitive answer to this. You can think about it -- the "normal" position is horizontal, so if the bed drops when loaded, the arm gets pushed up. How much for full braking? I don't have a clue.

 

Further, as far as I am concerned once the link has been removed ... all bets are off. The factory service manual procedure for adjusting it calls for a special gauge, and there's a spring or something (sorry, I'm going from memory here, not reading the book) that has to be replaced EACH TIME an adjustment is made. If the arm on yours is hanging loose, you have no way of knowing if it has been rotated clockwise, counterclockwise, one time or three times, or whatever.

 

The height sensing valve in my '88 blew out when I had to make a panic stop two or three years ago. After experiencing that, I do not trust them. They are all +/- 20 years old at this point. There's no way to test them for integrity, and you can't buy a new one. My suggestion is to eliminate it completely, run ONE new steel line from the front to the rear of the truck and connect directly into the rear flex hose. That gives you 100% rear brakes all the time.

 

If that's too much, then you can put a Wilwood adjustable proportioning valve into the steel line to the rear.

ok thanks

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