Mechanics

TRANS LEAKING FROM TOP VENT AT REAR

1991 Ford Aerostar • 104,000 miles

3L engine, 3 speed plus OD trans. No unusual noise or debris in the pan. Took a long time to figure out where it was leaking, but fluid is coming out of the little top vent at the back of the tranny. All functions of the trans are good. Just replaced the filter and modulator. No leak while at idle whether in gear or not, only after driving. 5-10 miles. Fluid level is correct (until it leaks out) I would call it a fast drip and leaves a palm sized puddle after the first stop when full, and puddle size diminishes there after. OD never worked since we got it 40k ago. Leak is recent and seems to come and go, but right now is steady. We are good mechanics but need info. We appreciate your help.

Glenn
Avatar
Docbrotherman
October 5, 2012.



Have a trans guy see if he canpull any codes out of it. It's leaking out the vent and normally that means an internal problem with trans.

Hmac300
Oct 5, 2012.
This is not an electronic transmission, so I can't imagine what codes there might be. The EDU currently shows no trouble codes.

I need to know what the vent is channeled to. Is it just an open vent for the tranny housing?

Tiny
Docbrotherman
Oct 6, 2012.
Yes it is just open to the case. But an internal problem would cause this unless it is overfull on fluid. Yes there are codes for this transmission. About the only thing you can do is to make sure that the vent is open other than that it's probably an internal problem.

Hmac300
Oct 6, 2012.
I have an OBD reader and it shows no codes. Is there some other way to read codes?

Also, would overheating and boiling the fluid cause this leak from the vent?

Tiny
Docbrotherman
Oct 6, 2012.
The code reader for the trans is under the hood. The elcetronic part controls the torque converter clutch and shift solenoids for 3/4it' by the driver side. You may stil not get any codes if it's a valve body problem or something else similar.

Hmac300
Oct 6, 2012.