stemen

My daughter inherited her first car from her mom when she turned 16 it's a 99 tracker. But I'm stumped with the 4x4 there is no indicator light and the pump runs for about 10 seconds then turns off it has 4-low but no 4-high. We ran it for about a hour in four low with out any issues but when it was in four high nothing any ideas would be a great help

L84sky

The pump only needs three seconds to pressurize the front differential and engage the 4WD actuator. The pump automatically shuts off after ten seconds to protect the pump motor from burning out. The ten second run time is an indication there is a large leak at the pump, or the hose from the pump to the front diff, or inside the front diff. The 4WD indicator light does not illuminate until the pump pressure reaches 5 psi. Pull the rubber hose off the bottom of the front diff and plug it with a Phillips screwdriver. If the 4WD indicator illiminates after 3 seconds the leak is inside the diff. The pump only affects the front axles. Are you saying the car goes forward in 2WD and 4WD-LOW but not in 4WD-HIGH?

stemen

2wd works fine and 4wd low works great it's a mountain goat but when you put it in 4wd hi it's just like being in 2wd

L84sky

That makes more sense. Your front axles are not engaging because your air pump is not building up pressure. In 4WD-HIGH, only the rear wheels are being driven. In 4WD-LOW, only the rear wheels are being driven but at half-speed and double the normal torque. If you think it's a mountain goat now, just wait till you get all four wheels pulling. If the pump fails to build up pressure with the line plugged (in the test previously described), remove the pump and apply +12 volts to the red wire and ground to the black wire with your thumb over the air line. If the pump does not shut off in one second you will need to send it off for repair. I'll post the address if you need it.

stemen

That would be great thank you

L84sky

I'll know how to proceed after you post your test results.

stemen

So I used my finger and plugged the actuator pump on the pressure side and the 4x4 light came on in side the tracker but went out as soon as I took my finger off the nipple the light went out again is this gonna be a pump issue or a diff issue

L84sky

If the pump ran for about one second (brrrrp) and held pressure (the 4WD light stayed on) as long as you finger was on the nipple, the pump is good.

Connect a clean length of tubing to the bottom of the front diff and blow into it. If it doesn't build up pressure (no more than 5 psi), there is a leak inside the diff.

stemen

Ok I will try that tomorrow thanks again

stemen

So I bought a new hose to just be sure and as I blew into the hose it did not build any pressure at all so I'm gonna assume it's the diaphragm inside the diff.