Trans fluid loss

[Tampergeorge]

I know I'm under qualified, having taken an AOD apart on my 91 Lincoln, and rebuilt a $)# for my dodge turbo. But I am at a loss as to why a 94 4WD Explorer would be losing fluid with no apparent leaks. Seals are dry, gasket is mostly dry. And I read here in the sticky about a vacuum modulator. I thought those were a thing of the past, but I'll look for it. I know my GMC had vacuum runing to the AT and the 4WD, and I know they had massive problems with the heater controls because some one deleted an "unneccesary" vent on the tranny. But that is GM. Any help or hints for me on this leak? I'd really lioke to see this woman get through the winter OK. George

 

[rickcdewitt]

I know I'm under qualified, having taken an AOD apart on my 91 Lincoln, and rebuilt a $)# for my dodge turbo. But I am at a loss as to why a 94 4WD Explorer would be losing fluid with no apparent leaks. Seals are dry, gasket is mostly dry. And I read here in the sticky about a vacuum modulator. I thought those were a thing of the past, but I'll look for it. I know my GMC had vacuum runing to the AT and the 4WD, and I know they had massive problems with the heater controls because some one deleted an "unneccesary" vent on the tranny. But that is GM. Any help or hints for me on this leak? I'd really lioke to see this woman get through the winter OK. George

wow same symtoms as my 94?the vacuum for the modulator comes from the vacuum tree on the driver side of the intake manifold.the rubber connectors on mine were soft/oily looking.i diden't see any fluid in the hose.but i'm pretty sure it was atf that softened the rubber.i'm not sure which line is for the modulator.does anyone have pics they can show which goes to the tranny and should the line get pulled off at the tranny to better tell if its leaking?i guess a vacuum hand pump with gauge would be the way to test leak down on the diaphram.anyone do this?

 

[Tampergeorge]

From what I've read, the modulator is on the right side of the tranny. From a much younger time, I can teel you to disconnect the hose there and check for fluid. If so, replace the modulator and hose. If the hose hasn't failed already, it will soon enough. My friends is a 4.o liter. george

 

[Glacier991]

The modulator is on the passenger side of the transmission just behind the servos and under the back end of the heat shield ... there will be a rubber line going ot it, and yes testing requires a vacuum pump, but if there is a) fluid in the hose, or b) the hose is soft ans mushy, you have a leaker.

Replacing it is unfun. If you DIY the replacement, make sure you are aware there is an actuator pin behind it that is often unknowingly dropped out during the removal. Without that rod you will have issues. Pay attention as it comes out. It is held in by a bracket that is secured by a bolt thingie that also serves as the attach point for the heat shield. You will need to remove the heat shield to remove the bolt holding the bracket that holds it in place.

I'd replace it.... it is about the only thing that fits your symptoms.

ps. When my 92 Explorer's modulator got replaced about a year ago.... I PAID someone to do it. I was busy and didn't relish the job, so $75 later my supplied adjustable modulator was in and I was a happy camper. This is one that I recommend you find a thuimbwheel adjustable model and PAY someone to install it. Ought to run you about an hour of shop labor.