Ford Pickup Dumped Its Transmission Fluid

[Bird]

My son-in-law has a 1991 Ford F150 standard cab, short bed, Lariat pickup with the 5.0L EFI engine and automatic transmission. Friday (a week ago yesterday), he said it leaked its transmission fluid out in a bank parking lot while he was waiting in line at the drive-through window. He left it in the parking lot over the weekend and had it towed in Monday morning. Now the mechanics say they put 7.5 quarts of transmission fluid in it, ran it, couldn't find any leak, drove it around, ran it most of the day, then parked it overnight, and still not a single drop leaked out. It seems to be running fine.

I know the gremlins do weird things at times, but I sure never heard of anything like this. Has anyone else ever heard of such? And if so, what could have caused it?

 

[SnowRidge]

Temperature related, perhaps. Might have been very hot, and a crack opened or expanded and is now cool enough to seal. It's all I can think of.

BTW, do you know where it leaked it from, the tranny itself or the cooler?

 

[Jimbrown]

As I recall this was fairly common for Ford transmission in the late 80's early 90's it blows it out the breather. I do not remeber what the cause was but it seemed to be random and sometimes never did it again.

 

[jinman]

Wow! According to what JimBrown said, that must mean your SIL needs to carry a 7-1/2 quart "emergency kit" around with him all the time. Very strange...

If it leaked out the breather, wouldn't that area be wet? Maybe the gremlins cleaned up after themselves.

 

[KennethBrown]

As I recall this was fairly common for Ford transmission in the late 80's early 90's it blows it out the breather. I do not remeber what the cause was but it seemed to be random and sometimes never did it again.

True story. My dads 92 F150 has done this twice in the last 5 years or so. For no reason at all it just spits it out the breather. Fill it back up and all is fine.

 

[TractorLegend]

Check the pump face clearance. The maximum should be not more than .003.
Ideally you should be around .0015. Also check the pump bushing fit.
Excessive clearance here will cause problems. Drill out the drain back hole
that is behind the seal to around 1/4 inch. Finally, is your son
pulling a trailer? If he is make certain he is NOT pulling in OD. Also
make certain that lockup is working properly. Non functioning lockup+ heavy
load+OD=overheated trans. I would check and make sure that the pump bushing hasn't walked forward and
covered the drain hole between the bushing and the seal.HTH

 

[Bird]

Check the pump face clearance. The maximum should be not more than .003.
Ideally you should be around .0015. Also check the pump bushing fit.
Excessive clearance here will cause problems. Drill out the drain back hole
that is behind the seal to around 1/4 inch. Finally, is your son
pulling a trailer? If he is make certain he is NOT pulling in OD. Also
make certain that lockup is working properly. Non functioning lockup+ heavy
load+OD=overheated trans. I would check and make sure that the pump bushing hasn't walked forward and
covered the drain hole between the bushing and the seal.HTH

Ouch, that would require pulling the transmission and I don't know what that would cost, but of course that may eventually be necessary. So far it's running every day with no problem. I don't think that truck has ever pulled a trailer, and it's very seldom gotten more than 20 miles from home.

 

[TractorLegend]

Ouch, that would require pulling the transmission and I don't know what that would cost, but of course that may eventually be necessary.

In our neighborhood tranny overhauls on late model electronic overdrives go anywhere from 2K and up for removal, rebuild and replacement with averages of 2500.00- its about the second most expensive thing you can do to a vehicle- engine rebuild being first.
An oversized trans cooler is a great insurance policy.

 

[dbdartman]

Thread hijack:

TractorLegend, you sound like you know your way around these things, so I have a question you may be able to help answer. I have a 94 F-150, around 161K miles, 302 auto trans, short bed extended cab. At around 70-80K miles something "funny looking" (like 1/3 of a piston seal lip) showed up in the trans pan during regular maintainance. Fearing something might not be quite right inside, the trans was rebuilt, because my parents were using the truck to travel on weekends (100-1000 miles round trip). Now the truck sees very little use, maybe 500-1000 miles/year. I don't know when it started, but for the last 4-5 years (since it was removed from daily/weekend duty) every once in a while, the trans will shift out of O/D for no reason what so ever while going down the road. I suspected the TPS might have been at fault, so when it was in for service a couple months ago I had it changed. The trans did nothing funny returning from the service garage, so I though it may have been fixed. Wrong... After replacing the leaking oil drain plug gasket last weekend I took the truck for a 7-8 mile drive, just to exercise it some. After about 4 miles, the trans shifted itself out of O/D & into 3rd gear while going down a hill! After a couple seconds, it up-shifted, a mile or so later it did it again, then was normal the last mile or two. Other than this anomalie the trans shifts fine (except that being a Ford computer controlled trans, it does what it wants, when it wants, not what I want when I want, like my old torque-flites, or my 04 Colorado & has been this way since new).

Any thoughts, hints, suggestions?

My apologies to Mr Bird for the hijack!

 

[Bird]

My apologies to Mr Bird for the hijack!

No problem. Most of us (well, me anyway) have done the same thing occasionally. Hope Tractorlegend (or someone else) has a cure for you.