Info for the ALL system (automatic load leveling)
 

I have some information that might be helpful for this board about the "ALL" automatic load leveling system that uses an air pump locatedjust behind the passenger head light below the anti-lock braking motor.
1) The MPV with this system has different coil springs on the rear axle than MPVs without the system. The regular MPV springs are stronger and thicker, therefore will hold up the van's rear end. The ALL system springs being "weaker" allow the rear of the MPV to go up and down with the amount of air in the shocks and basically help the air shocks hold up the rear end. Many people replace the ALL equiped MPV springs with those from a junked MPV without the ALL system.
2) You can just replace the factory shocks with gabriel or monroe air shocks. I would have to look up the numbers but they are available. However, they are different for the 4WD versions as oppose to the 2WD MPVs. There are many places to put a tee shaped valve like an air valve in your tire. Just pump them up as desired.
3) You can pull the fuse to the air pump to keep it from running all the time. But if the pump is running all the time that means there is an air leak, and if the pump runs to much it will blow the fuse and quit altogether. Replace the fuse and it is just a matter of time til it blows again. Find and fix the leak.
4)The first place the system leaks is usually were the hose goes into the pump/tank. The fitting is very unusual and only comes with a new pump/tank (about $900 new!) There is a junction fitting about mid length of the van between the gas tank and the drive shalf. There is a tee connector over the rear axle that can leak. Just a reminder, the hoses are metric size, not American and they are not interchangable because they will not seal and hold pressure.At the pump there is a plastic resevior tank. It is possible to drill out the metal sleeve that the push fitting goes into. Then tap the plastic tank with american blind tap and put in a brass nipple that is threaded on one side and has the standard compression ring and nut on the other. Be careful when tapping the tank. There is a check valve right where you tap and it cannot be damaged or the tank will not hold the air after being pumped up to pressure. I used epoxy on the threads to seal it to the tank. I then replaced the tee fitting over the axle with standard american brass ring and nut compression fittings and used the standard plastic lines that came with the Gabriel or Monroe air shocks. The line that goes from the pump to the tee fitting is a larger trunk line than the lines that go from the tee to the shocks.
Another place the system likes to leak is where the tank attaches to the pump. Since the tank is plastic, where it attaches to the pump has two plastic "ears" that engage the metal fitting on the pump sealed with an O-ring. If this breaks, new or junk yard pump is required. There is a level sensor attached from the body to the rear axle that uses a lever to move along a resistor to give the system the information to make it's adjustments. Easiest way to disable is to pull the fuse to the pump, and if the flashing light bothers you, pull theinstrument gaugesand remove the light bulb.
I hope this helps.
Du907