Transmission Fluid Loss

[JeepExplorer]

1994 Stock Explorer - 170,000 miles. Everything working as it should except that I have to add approx. 1 qt. transmission fluid every 1,000 miles. It's not going into the cooling system (coolant is that lovely green it should be and level is constant) and it's not going onto the ground (park on clean concrete - leaks would be visible).
It's not splashed all over the tailgate/back window (like other vehicles I've had in the past after long journeys) and the underside of the truck is dry everywhere. So I'm at a loss to understand where it's going? Any ideas or suggestions will be welcome. Thanks - and 'Merry Christmas'.

 

[natenkiki2004]

Could be vacuum modulator leaking and sucking ATF into the vacuum line. Pull the vacuum line that is fastened to the top of the upper intake manifold and see if it's wet inside.

Aside from that, it could be leaking at the bellhousing, there's a gap where the midplate/gutplate goes and if the front pump seal leaked, it would drip out of there without leaving much residue on the underside of the vehicle but it should leave spots where it's parked, especially after long drives.

 

[JeepExplorer]

...aaahhh - of course! Thanks natenkiki2004 for reminding me of the vacuum modulator. I can confirm that one of my vacuum lines on the rear left 'tree' on cyl. head is very wet with oil - it slipped off the other day! Thanks again - I'll change the modulator asap and advise.

 

[natenkiki2004]

No problem How long have you had this problem? It might be wise to run some Seafoam in to clear out the carboning from the ATF.

 

[JeepExplorer]

Gotcha! I have some Seafoam and will use it when I've changed the modulator. I've had the problem for a while but I do so few miles in the Explorer (only 4K last year and so far only 2.7K this year) that it took me a while to realize that the ATF was dropping so fast. In fact I only checked after I reversed out of the driveway and put it in drive and there was nothing there for 4/5 secs.

 

[JeepExplorer]

Thanks again - Modulator replaced - vacuum line flushed - fluid level corrected with hot eng/trans - engine 'Seafoamed' - 200 mile run and fluid level exactly where it was at beginning. Hopefully that's it!

 

[natenkiki2004]

Glad to hear it was relatively simple and worked out!