Thread: advice to drain atf via cooler pipes?

It's a bad idea to let it pump dry. If you were able to assure new clean fluid made it in the other cooler line, you'd probably be ok. I've seen some shops that have special equipment that they use to exchange fluid like that.

If your trans has a few K's on it, it could do more harm than good changing all the fluid in one go.
Plenty of vehicles drive in to get trans flushes and dont drive out.

If your fluid is not burnt and the filter is clean, I would just leave it, if of course you dont have any issues with it?

That is the problem. I did a full change 12 months ago. Pretty much first ever and was black, as well the plastic tubing around the wiring inside was all melted. Must have been over heated. It was running ok though.

Since then though been having trouble as you warn off. And been trying different things to fix it, not that there are many options.

A couple of bottles of Lucas additive worked the best and stopped it not shifting into 1st in the mornings. But it seems to have degraded further now as that's happening again plus its not shifting into 4th/od regularly until you rev it real high, that's how we get out to change out of first too when it sticks...

Anyway bought a couple of bottles of transmax as a last attempt but wanted to get out as much of the old fluid as possible. Maybe even running some cheaper stuff through first too do this better.

Also not sure if there's much a tranny place could do either, except for the machine you mention?

I haven't done it but I've read that you can pull the return line from the transmission oil cooler. The idea seems to be that if you rig up a hose/reservoir arrangement to the return line you can keep up a flow of fresh fluid to the tranny while the old fluid is pumped out via the oil cooler. It sounds good in theory, and I think a few members may have done something similar.

It could do more harm than good, but as you are having these problems, and a rebuild is on the cards, give it a go and see how it turns out.

Doesn't sound too promising though.

Good luck with it!

Yeah, I think a rebuild unit is going to be the real fix as just now towing a mild weight up some hills the transmission temp light has been coming on when it never had before (since I've owned it)...

Originally Posted by OffTrack

I haven't done it but I've read that you can pull the return line from the transmission oil cooler. The idea seems to be that if you rig up a hose/reservoir arrangement to the return line you can keep up a flow of fresh fluid to the tranny while the old fluid is pumped out via the oil cooler. It sounds good in theory, and I think a few members may have done something similar.

I have done this on numerous occasions. Just make sure that you have a good pump and plenty of oil. I remove pan first and clean/do filter. Then refill. With rear return line disconnected, connect some clear hose to it and put other end in collection container. Start the motor and then pump in oil as the old stuff comes out of the cooling line.

This was the method we used when ever fitting a reco auto as a way to get old oil out of the cooler. As for flushing the auto, it works well as the oil that you can't otherwise drain is what is trapped in the converter.

When the engine is running the feed from the auto to the cooler is via the converter, as this is where the hottest oil is.

As for the best place to disconnect, I usually do it at the auto

SiddersC the issue is neglected changes rather than age of the transmission. The auto is designed to have the oil changed every 40K km or possibly even 20K Km if you assume the service schedule's arduous usage "transmission oils" category covers the auto. It seems that problems post-change occur when fluids changes are not done regularly.

Haydent, did you do the filter when you did the last fluid change? I'd be very tempted to do the filter again even if you did it last change.