sychu

During ATF fluid replace I noticed that metal pipes (for transfer fluid from AT to cooler) are completely rusted :-(







I need to replace them, and I'm looking for some answers:

1) After replace components should i worry about air inside components. Does ATF require some kind manual "venting" after replace?

2) I checked price of "both pipes" and they are quite expensive. I was thinking about replace them with "hydraulic hoses". Any particular reason why i should use "geniue expensive easly rusted pipes"?

3) My impression was that "cooling round" gous through dedicated "cooler" (under front right fender liner) but also additionally through main cooler am i correct or i'm not looking right? I need to be aware what I'm disconnecting :-)

fastnoypi

1. No, the transmission has a vent, just check fluid levels after driving a while.
2. The hard pipes make it easier to allow for angled bends and sharp turns than hydraulic hose

3. not sure what you mean by "cooling round"

sychu

Thanks for reply!

Embedded vent is a really good news! It will make my work much easier and I will be able to fix it without additional helper :-)

You are right metal pipes are bended with sharp turns. I will try to find used "hard pipes" first.

Sorry for "cooling round" (it is due my poor English). I mean "cooling circuit". It looks like ATF fluid goes through dedicated cooler but also goes through some part of main cooler. I will double check my observations tomorrow.

Thanks again!

fastnoypi

Unless you have a towing package with an external transmission cooler, the fluid is cooled through a dedicated passage in your radiator.

Honestly I would wait till the pipes are rusted through and showing leaks . You can attempt to wire brush them and spray with a rust protector. It would buy alot of time so you can look for a good price on a new unit.

sychu

I don't feel comfortable with current shape of pipes. It seems that there is not much pressure in "ATF cooling circuit" and any small leak should not be spectacular ;-) But it will not let me drive with peace of mind. If I will start to drop fluid on the road is there any symptom that will let me know that fluid level become low (before complete AT crash)?

I would like to identify "fluid in & out" for "ATF flush":




1) IN or OUT?
2) IN or OUT?
3) IN or OUT?
4) IN or OUT?

Regards

fastnoypi

Low ATF , your car won't shift properly.

I'm not sure if anyone documented it, but you can figure out the flow by undoing a clamp, attaching a 3/8" clear length of tube and seeing if the ATF will pump out or dribble out once someone puts the car into reverse while the foot is on the brake.

carguy07

FYI

https://www.clublexus.com/forums/rx-...il-cooler.html

sychu

Ooops... You right it is far better topic for questions & answers about rusted transmission pipes.

sychu

Thanks, if I decide to do flush during pipes replace then I will update this topic with my observations.

This forum is amazing source of knowledge. In my country automatic transmission is not popular and scary for most car services. Authorized Lexus service is not far from me but it is very expensive, especially in compare to overall value of 15 year old car. Without this forum I would be forced to sell my "smoczyca" (it is how my daughter named a car .. "she dragon" ;-)

Drcoffee

I'm in the process of deleting the factory cooler, replacing the old condenser and old radiator and adding a B&M 70264 trans cooler in front of the condenser on the passenger side. The cooler is rated at 20,000 BTU.
My steel lines are rusted out but, not leaking. if anyone needs a factory cooler, it will be for sale soon. It looks to be in great condition.

This may actually reduce the length of fluid lines at the same time. I'm not actually sure what Lexus was thinking with the twisted steel lines. The circuit will go from trans -> in radiator L -> out radiator R -> around the right side of radiator to the cooler, magnefine filter, around the left side of radiator and back to the trans. In the process, I will secure the hose to the backside of the bumper. This will make changing the filter in the future a snap. Wont even need to open the hood.

Drcoffee

#4 is the return to the transmission
#3 is fed from the radiator and leads to the aux cooler

The fluid path is: left radiator -> right radiator -> #3-> #2-> #1-> #4 transmission

salimshah

Post retracted

Salim

murphysf

Hello,

Excellent DIY.

I attempted to do the complete job yesterday however only ended up draining and refilling the atf from the pan and differential.

I chickened out when I got to the step to remove the pan. It was the front pan bolts that were hard to get at. I don't see how removing the splash guard would aid in removing the front pan bolts as the pan bolts seem to be closer to the rear side of the unibody cross member or what ever the body support is called that goes across the vehicle that makes the front pan bolts hard to get at.

Perhaps it was due to the tool setup I was using. I had a 1/4" 10mm deep socket that was on a short 2"-3" extension. I could barley get the socket on the head of the bolt and was afraid if I attempted to remove them I would round them off.

Those that are successful at this how were you able to remove the front pan bolts? From the splash guard side or the other side?

Maybe a regular (short) socket and a universal joint swivel socket adapter would have helped??

So just did the drain and refill. Took about 4 quarts. The diff plug was really loose but not leaking. It had a bit of blackish gunk on it. Now the transmission pan drain plug has a very slow drip. I guess I should have replaced the washer?

murphysf

or instead of using two pieces (a socket and a universal adapter) how about a one piece flex socket?

carguy07

I think I just used a regular 1/4" socket on a wobble extension. Didn't touch the splash shield.