E40D Factory Trans Cooler at Radiator - How to test for proper flow of trans fluid?
 

Hello-

My trans temps, now that I have installed a trans temp gauge (sender at test port), are reading 201-230 degrees F once the trans has warmed up (45 min). This is city driving, stop and go, with ambient temps at 100 degrees F. No load.

Trans has been serviced with new 4WD pan, 4WD trans filter, and fresh Mercon V fluid.

How can I determine, with the least mess possible, if the trans fluid is flowing its way through the radiator as it is supposed to do. I have heard it can get blocked inside the radiator causing trans temps to rise. Radiator was back flushed just after trans service with fresh coolant added.

I plan on adding a Tru Cool MAX trans cooler (see link), but I would like to know, prior to install, that there is no blockage causing temps to be higher than they should be.

Just unbolt the output and run a piece of hose into a 5 gallon bucket.

So I unbolt the output line, attach a piece of hose around the end, stick in a bucket and turn engine on? For how long...a few seconds? Will it immediately begin to pump fluid? What type of pressure should come out of line when engine is started? If fluid does come out, does this mean it has passed through radiator and in turn indicates that the radiator trans cooling portion is not clogged?
Thanks

searched but couldn't find anything on the testing procedure mentioned in post #2

Pull the line leading to the factory radiator cooler, attach a hose. Place the open end into a clean empty bucket (2-5 gal.) Start the truck let it run for 30 seconds, shut it off. Pinch the hose closed. Mark the height of the fluid in bucket. Put the fluid back in the transmission.

Remove the hose re - install the cooler line. Remove the line leading away from the cooler, attach the hose, place the open end in the bucket. Start the truck, let it run for the same amount of time as before. Shut off the truck, clamp the hose shut. Inspect the fluid level in relation to the mark previously made in the bucket. If the levels are very close to the same that means the factory cooler is not plugged.

Am I pulling the metal trans lines right where they connect at radiator?

INTO radiator FROM trans would be TOP line
and
FROM radiator TO trans would BOTTOM line, correct?

Thanks

The opposite.
The bottom line is the feed from the transmission. The top line is the return.

The opposite of the opposite. Top line comes FROM the trans, bottom line goes TO the trans. Just like the rad hoses on the engine, thermostat hose goes to the rad, bottom hose goes to the engine. Heat rises, so the fluid at the bottom of the rad/cooler will have a lower temp then the fluid at the top.

I stared at this pic for hours:
https://www.f150online.com/galleries...939-174420.gif

It sure looks like the return is from the top port (The rear most cooler line is the return).

I went back to a post I recalled from another forum: E4OD Transmission Coller Line Routing

There is the answer!

Thanks eakermeld for pointing out my mistake!

I can confirm this form my Aux. Cooler install: the TOP line going into the radiator is the line FROM the trans, the BOTTOM line is the one goint TO the trans, since it's never a bad thing, you can check that in my E4OD mods link in my signature. This is also easy to tell since the line going to the front of the trans dumps the ATF basically over the pan, where the ATF get's sucked in through the filter.