My 92 F150 automatic is losing tranny fluid but there are no visible drips. When it gets low it slips when turning left. When I top it off again slips go away, only loses about 1/2 cup per 3 months. Where is it going. A friend said there is a vacuum line from tranny to engine, could it be burning it out of the exhaust?

 

Is it 4wd? The seal between the tranny and transfer case could be leaking.

 

No, it's 2x4

 

I don't know whether they still used them or not in 92, but if it has a modulator the diaphragm could be cracked and that will allow fluid to be sucked up the vacuum line.

If I go to Rock Auto and look a modulator up for a 1992 F-150 with 302, it only lists them for a C6 transmission, which I believe was no longer used in the F-150 in 92. The C6 is non-overdrive. The E4OD is fully electronically controlled. The AOD has a TV cable, no electronic controls, and I don't know if it has any vacuum control devices.

 

Yeah, a 5.0 in '92 is only gonna be an AOD or E4OD. No vacuum modulator. Leaking in use would be my guess.

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