You can purchase the pump at any auto supply store, Auto Zone, O'Reillys. Advance, etc.
There is a drain plug on the bottom of the transmission. To fill it, there is a plug toward the top of the transmission case where U have to pump the new fluid in till it starts to drain out.. There is no fill or trans. dipstick in top.
when accelerating, if the transmission seems to "jump" or "slip" and is fine after that, it's probably low on fluid. while the trooper is on and in park, pull out the transmission dipstick to read the fluid level. wherwe is the dip stick 2002 Isuzu trooper,thank you the 2002 trooper has no tranny dipstick, you need to check it from under the car. on the tranny pan are two drain plugs. one to drain, one to fill. you need to pump the fluid into the fill plug hole. this is best done at a shop that has a pump . fill it up until the fluid runs out the fill hole. quickly replace the plug. do this on a level surface.
The Isuzu has a sealed transmission. It has a transmission fill plug on the side of the transmission above the pan, I believe on the right side of the trans case about midway the case body. Take the pan off remove and change filter. Add fluid by using an inexpensive pump until the fluid starts to run out the fill plug hole. Replace the plug. Job done.
In the fuel tank
It is in the fuel tank.
underneath the gas pump in a 1993 trooper.
replace the pump replace the pump
Unfortunatly you cannot check the transmission, or add fluid yourself. You have to take it to a dealer, or a transmission specialist. That's not strictly true. The Trooper uses a GM "closed" transmission system. Its possible to do it yourself, but a real PITA and requires some kind of pump system to pump in the fluid from below the vehicle. There are 2 filling bolts on the transmission pan, the lower one is the drain, the higher one towards the pan corner is the fill/level plug. You must remove the fill plug and pump fluid into it until it starts to run back out. Run the engine to distribute and warm the fluid, then check the level again, topping up if necessary. Replace the plug using new seal.
43 psi
in the fuel tank
on the left side of the transmission is a sensor. carefully remove it and pump/squeeze fluid in that opening up to the bottom of the hole. replace sensor.
dextron or mercon III, you have to pump it in from the bottom.