Transmission Oil Cooler Lines

Was wondering if there are any o-rings between the fitting at the transmission end of the ATF cooler lines where they screw into the inlet/outlet fittings. I can see on the parts diagram that the fittings themselves have an o-ring. Has anyone taken these lines off and can confirm if o-rings are present? Mine is a 1991 LH107 with the 3L engine and A45DE auto trans.

I've been draining/filling the ATF since I got the van last October due to the fluid being reddish brown (note I didn't say brownish red ). I did the third drain/fill today and after test driving noticed that there was ATF leaking off the cooler lines. It looks like it's leaking where the line screws into the inlet fitting (only did a quick peek as it was dark and raining). i'm wondering if the new ATF is cleaning out gunk and causing old seals/rings to start leaking. I figure I might as well replace the inlet/outlet o-rings while I'm at it. Heck maybe they're what's leaking, need to get a closer look  

Edit: it appears the leak is at the inlet fitting. Has anyone removed this part, and what is the electrical connector attached to it?

Difficult to see where the leak is, it may be worth cleaning it up with brake cleaner than have another look after a few miles.

Good call. I've got some errands to run today, so I'll spray it beforehand. There is a red sheen on the fitting right at the case, hard to tell from the photos though.

Here are a few before/after pics after an 80 mile drive. Can see that the inlet fitting is now wet from the case down to the line fitting. Looks like the line fitting is leaking too since the leak at the case probably couldn't reach where the line goes into the fitting.

I picked up the new o-rings yesterday and will take some photos when I get everything taken apart, cleaned up, and reassembled.

Before


After


Before


After

Oh yes, pretty conclusive, good to see exactly where the leaks are - top detective work!

Good luck fitting the o Rings. Hope the nuts all behave themselves.

Got around to replacing the o-rings. The nuts on the lines were on really tight, but they eventually gave way. You have to remove the line nut then the temp sensor before you can loosen the nut at the case and then unscrew the elbow pipe. Got it all back together but didn't have a way to measure re-torquing the elbow nut to 25 lb-ft, so whatever I applied seems to be doing the trick. I am noticing a slight weep at the line nut now, so will have to see if I can tighten that more tomorrow. But it seems like the elbow and sensor are staying dry now, so that's progress?!

Genuine O-rings? Did you manage to order those from Toyota?

Glad it all came apart without snapping something off, shows the metal is still good and always saves a lot of time and money..

Your fluid looks good, nice and red so you'll have a nice clean gearbox too.

I was able to get them through my local Toyota dealership. I asked and they said that they are still using them for a half dozen US market vehicles.

This was my fourth drain/fill, I ended up draining almost 4 US Qts between the pan and the cooler lines. There should only be ~10% old fluid in there now.

Now I have to do the same exercise with my coolant! There was rust scale inside the hoses so I had them all replaced. My mech recommended that I flush several times over the first year of ownership

Thanks for the info, very interesting, esp about the cooling system.