Thread: ATF dip shows overfull & bubbly - cooler line leak from new rad

'01 GTP, no mods, 153k mi.

Few days ago i replaced my radiator due to a cracked tank. Dropped in a new Spectra Premium branded radiator. Coolant maintains proper level now, but have run into another problem. The lower trans cooler line is leaking where it meets rad.

Rad came with new threaded fittings i installed into rad. Had some yellow stuff on the threads, presumably sealant, I put 2 wraps of teflon tape around threads as well before installing. Been keeping an eye on stuff looking for leaks, and saw ATF on the core support grommet. Pretty good drip down the plastic lower pan, onto the frame rails a bit too.

Today, i gave the fitting a little more torque, thinking maybe it was just loose. Cleaned up bottom of car to make spotting leaks easier. Went for 15 mile drive to warm up ATF to check level, as specified in the owner's manual. Park, shift through all gears, back in park, check ATF with engine running.

ATF is showing on the dipstick all the way up to the curly bends on the dipstick! Looks bubbly too. What would cause this?

Leak looks pretty substantial, cleaned up bottom of the plastic pan, frame, pretty much everything i could get to with car on ramps this morning before drive to warm up trans. Pretty messy again after 15mi cruise on highway. Can post pics if needed.

I did notice while leaving the house, that it seemed to hold 3rd longer than usual [5-10 sec] before kicking down to 4th with cruise on at 65mph. So, what's my next step here?

'01's have that 3 point spring clip holding the Trans lines right?
What threaded fittings? But O.k.

Check around the the tank for cracks. I also had the Collar nut be loose and leaks from the factory.
I'm assuming there is air getting sucked in on the low side and adding Volume to the fluid.

Originally Posted by Gregorius

'01's have that 3 point spring clip holding the Trans lines right?What threaded fittings? But O.k.

Yup, spring clip. By threaded fittings, i meant the actual piece that has the clip in it. They weren't pre-installed on the new rad.

Rad was checked over before install. Went ahead and put on fan/shroud before dropping it in all as one piece.

Crawling under the car and looking, its definitely coming from the flare/clip-ring area. Is there supposed to be an o-ring in the fitting before pressing the line in? Posted thread on r/mechanicadvice as well, was advised missing o-ring most likely culprit. New rad did not have any with it, forgot to check old one before scrapping it.

ATF shows overfull while cold and off as well, was told to pull out excess with a pump and line fed down through dipstick tube.

Originally Posted by wstefan20

If you overfilled your transmission with fluid, it will cause it to foam. If the leak is substantial enough, you could be losing prime with the pump or just foaming the fluid due to air getting in.

Bought car in Sept, have put about 3k miles on since. I haven't touched ATF fluid or dip at all prior to this. Thinking P/O must have overfilled it, or their mechanic did. Only fishiness i've noticed, is yesterday it seemed to hold 3rd longer than usual @ highway speeds before kicking down to 4th. Right as i was leaving my driveway.

Is there supposed to be an o ring in the connector or on the cooler line before pressing in? If so, think I've found my leak. New rad didn't come with any (Spectra Premium) and i forgot to check before scrapping the old original one.

Gonna take the truck into town for parts run here in a bit. Will pull top threaded connector to take for reference, and get 2 new ones, along with o-rings from NAPA or Oreilly's. Rent a pump (or buy something similar) to pull excess fluid from trans.

A tech told me get it to under the full line while off and cold, then drive to warm up and recheck, top off as needed. About an inch difference between cold/off & warm/running on dipstick.

I'll let yall know how it goes once i get it buttoned up.

Update: Ok, got the leak slowed way down, if not stopped.

Pulled the top threaded piece, realized they already came with o-rings for the straight section of line. Neat. Cleaned up teflon and yellow thread sealer. Lost clip, so add that to the list for parts store.

Get up there, no one in town has fittings in big enough thread size. Nor do they sell just clips. Great. Have to buy a wrong-size fitting just to steal the clip from. Picked up that, o-ring assortment, and some blue loctite. Some of the fittings come with another o-ring that would get squeezed between shoulder of fitting and the rad itself. So lets try that.

Pull both threaded fittings from rad, hit lines with wire brush and inspect for damage. All gravy. Clean all threads with shop towel soaked in brake cleaner spray, add o-ring to outside threads, then hit it with a healthy glob of blue loctite. Thread in by hand, then get it nice and tight with the ratchet. Left clips out to make sure flare fits in firmly. Seat lines, replace clips. Clean up the mess from the drip, and hit the road. 20 mile round trip, all highway at 65 mph.

Theres a bit still coming from the bushing that holds rad in core support, and a few drops on LCA. Might be some i couldn't get soaked up. All in all, much cleaner than last time! No signs of leak from both actual fittings. Re-cleaned all mess from under car, gonna continue monitoring. For now, she's on light duty/parked, ol' blue (my pickup) is back to primary.

BTW, MacGyvered together a big syringe and some clear line to pull ATF thru dipstick. It... wasn't pretty. Way too damn dark for me to feel good about, so dropping the pan and fresh fluid is happening as soon as budget permits. I'll just get it at right level that way. Wanna wait til I have a shift-kit to go ahead and toss in while the pan is off and fluid drained.