alanz123

Hi All,

Hope someone can help me. I have a 1991 928 S4 with 68,000 miles on it that I have been working on for about a month (Intake Manifold job). Just this past week I came into the garage and found a bunch of transmission fluid on the ground. Does anyone know why and how this could happen? This car never had Transmission leaks at all and was just had the Transmission service 3 months ago. Keep in mind the car was not driven for almost a month due to the Intake Manifold maintenance.

Thanks for your time.

Alan

Sailmed

Alan, this has happened to many folks with the reservoir overflowing while parked for long periods of time, the torque converter drains into the reservoir. They have simply checked the level, filled if necessary, and not had a recurrence. What was the fluid level when you started it up?

Randy explains it perfect in this thread...
https://rennlist.com/forums/928-foru...rans-leak.html

alanz123

Hi Mike,

Thank you for responding so quickly. I am almost done with the Intake Manifold project and will start it up this weekend. Anything I should take into consideration before I put the car in reverse/drive? Can I drive it at least to my tranny guy? My Transmission guy is exactly 1 mile away and said he can check the levels once I bring it in. Do you think its safe to drive?

Mongo

ATF on the floor also indicates the pressurized oil cooler lines from the transmission to the front of the car are failing. These have sections of rubber hose on them that can go bad after years. Both of mine failed causing 2 gallons of ATF to pool on the floor. At my house it's called the 928 Menstruation.

alanz123

Thanks for the link to. Yes, the fluid looks clean and red.

Cosmo Kramer

On my car, the little rad cap on the reservoir was missing its gasket. I made one with neoprene and fixed it. You have to take it off when the engine is running to put in the gasket because the reservoir overfills when the car is shut off.

auzivision

The system holds around 9 quarts. It will still operate at around a quart low or just starts acting up, for sure a half quart low is safe for short distances. So it really depends how much leaked out and how close it was to full before leaking.

A puddle smaller than a pizza should be no problem with a 1 mile drive especially if you don't drive hard. If it took more than 3 or 4 paper towels to clean up, you probably want to figure out how to fill it up (or fix it) before driving.

auzivision

Another thing you want to consider is where is the leak (where was the puddle)… if it’s anywhere along the cooling lines above the exhaust, potential fire hazard. That’s roughly anywhere forward of the rear edge of the doors.

Althoug, it’s not a very likely place to leak because these are hard lines (except for the connections) and the exhaust won’t heat up that much within 1 mile. Most cars are still spewing water after one mile indicating the exhaust is hot enough to vaporize water.

Most leak back by the tranny and/or torque converter which won't be a problem so long as it's not streaming out.

scottzj

My S4 did the same thing to me a few days ago and I about lost it! LOL Then I searched on here and found that this is a normal occurance. My hoses up front are fine too, so I feel mine was just due to it sitting awhile.

Sailmed

Watch for little kids on bicycles, old pharts walking, other cars, the usual suspects....


Do I think its safe to drive?


Not if you've been drinking.

Bill Ball

If the puddle is right under the reservoir, this is due to a bad/missing gasket on the cap or cap put on loose or a bad/missing/loose overflow hose on the top of the reservoir that plugs into the tranny. When you park the car, the reservoir will fill up but should hold fluid if the above are in good shape.

Mrmerlin

since you recently got a trans service, it is possible that the new pan gasket has split, this is due to over tightening /possibly using the older style pan gasket.
And as previously stated a loose filler cap, or leaking hoses

borland

The only vent for your transmission is at top of the casing. So if your experiencing a leak, you've got a problem with a seal somewhere.

Contrary to what Cosmo said, if the fluids are properly filled, you can take off the reservoir cap with the car level and the engine off and not have an overflow situation.

auzivision

I disagree... don't ask me how I know.

The Torque Converter drains back into the tranny when not spinning. Maybe this isn't proper, but it happens often.

Don't remove cap without runing engine... I'm sure others will concur.

Mrmerlin

if you remove the cap and shut off the engine you will have a large ATF leak since the fluid is draining back into the pan, dont try this unless you put a pan under the car