98 S90 ATF dripping from some hose

thefisch · Post by **thefisch** » 28 Jul 2019, 20:38

Noticed a few drops of ATF on the garage floor and then again a few days later on the driveway. Going to get the car on a lift later this week and inspected, but in the meantime I took a couple of pics from underneath the driver side.

It seems the fluid is dripping from the hose with the white clip in the photos below. Can anyone tell me what this hose is for? There is some fluid on the blue tape on the hose to the left. I realize that leaking fluid can travel in strange direction due to airflow, but this hose seems like an odd location. The transmission pan itself seems dry and didn't see anything dripping from it - it was resealed about 10 years ago.

: wide view

: close up

Post by **RickHaleParker** » 29 Jul 2019, 08:21

Dope the ATF with Trace Dye. That way when you got it the lift, you can trace the fluid back to the source.

projectsmorol · Post by **projectsmorol** » 29 Jul 2019, 08:49

I concur with mr rick as these types of issues are nigh impossible to diagnose without physically being there with experience to see
the possibilities.

thefisch · Post by **thefisch** » 29 Jul 2019, 10:36

Appreciate the responses. That is a great idea.

Incidentally, I looked further back on the car and think the 'hose' in the picture is actually sheathing for a cable to an emissions sensor. On the rear side of the bracket for the rear transmission mount (which the cables pass over that bracket in the photo), these cables then cross over to the passenger side going under the tail end of the transmission and drive shaft. Then they continue on the passenger side and connect to sensors in the exhaust. So for ATF to get on them, perhaps it is leaking from the tail end of the transmission onto the sheathing and then running to the lowest point.

projectsmorol · Post by **projectsmorol** » 29 Jul 2019, 11:32

Unfortunately, you are only going to get speculative answers here or any other blog/forum. A "leak" is on an individual bases. Everybody has a different circumstance. Leaks come from different places at different times on different days from different temps etc.
If you have the ability, you are best to wipe everything down with a microfiber to make SURE it's clean, run the car to temp to heat/expand the fluid to cause the leak and then look to see where it originated. Option two, put contrast/dye in the tranny fluid and see where it's coming from.

thefisch · Post by **thefisch** » 29 Jul 2019, 11:53

Thanks. I was mainly trying to determine what that 'hose' is to understand how/if it relates to transmission fluid. Bit it appears to be a cable for an emissions sensor and just a 'victim' of the leak. Still need to inspect the car for the source.

dm635 · Post by **dm635** » 29 Jul 2019, 17:34

You are correct. That is not a hose. It's wiring from the O2 sensors. Looks like that pan has been sealed. You can now get a rubber seal that works much better than the old sealant you used to have to use.

thefisch · Post by **thefisch** » 29 Jul 2019, 17:42

dm635 wrote: ↑29 Jul 2019, 17:34 You are correct. That is not a hose. It's wiring from the O2 sensors. Looks like that pan has been sealed. You can now get a rubber seal that works much better than the old sealant you used to have to use.

Thanks for confirming that. And yes the pan was sealed due to a leak about 10 years ago. That's good to know they have a rubber seal in case that's where the leak is.

thefisch · Post by **thefisch** » 30 Jul 2019, 15:33

Was able to inspect today and the leak is coming from the servo cover in the upper left of the first photo posted above. Fluid is seeping out and, thanks to the wind, running down lip of the pan towards the back of the pan and also getting on the cables adjacent to the pan lip. Going to check on replacing the o-rings. Good news is the leak was small.