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FSM09, Ford Senior Master
Category: Medium and Heavy Trucks
Satisfied Customers: 3630
Experience:  Ford Diesel certified, specialized in Ford diesel repair
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I have a 2000 f350 deisel 4x4 dually It has a automatic 4r

Customer Question

I have a 2000 f350 deisel 4x4 dually It has a automatic 4r 100 transmission and I am in the towing business and four the last three months I have to pull over and let the tranny cool down it has the cooler lines go to radiator and then a front external cooler below the radiator why is this thing overheating and what can I do to prevent it from overheating again I've been pulling over when it gets to 220 degrees
Submitted: 1 year ago.
Category: Medium and Heavy Trucks
Expert:  FSM09 replied 1 year ago.
Hello, I would add an aftermarket cooler with an electric fan to help cool the fluid. The 4r100 is known to get hot when towing and can burn the transmission up quick. If it happens a lot the external cooler can be plugged as well. I would look for an external cooler with electric fan you can turn on. This will help out more then anything else will.
Expert:  FSM09 replied 1 year ago.
I would also flush the fluid with fresh fluid I case the current fluid is broken down.
Expert:  FSM09 replied 1 year ago.
If you have other questions please let me know. If not please remember to rate my answer so I receive credit for assisting you.
Customer: replied 1 year ago.
I allready put an after market cooler and a electric fan it didn't help much I'm on the side of interstate as I type this fluid has been changed twice in last two months I pulled cooler line and started the truck the fluid came shooting out about two feet so it looks like good pressure Im lost on this one is there any thing else I can do next I'm gonna put full size radiator in as cooler I guess .
Expert:  FSM09 replied 1 year ago.
If that didn't help I would suspect maybe one of the cooler lines might have a restriction causing the cooler to not correctly do there job.
Customer: replied 1 year ago.
Did u read my ? Fully I said I pulled the cooler line off and started the truck and it shot out 2 or 3 feet is that normal or should it be more than that? I shouldn't have to pull over to let it cool every 25 mile they should of had a recall on these trannys
Expert:  FSM09 replied 1 year ago.
I'm sorry I don't see anywhere above where is says the cooler line was removed.
Expert:  FSM09 replied 1 year ago.
A couple more options would be to install a transmission cooler from a 6.0L diesel. It is three times larger than the 7.3L cooler. Next is the cooler bypass valve can be bypassed so the transmission is always running fluid through the cooler and see if it helps.
Expert:  FSM09 replied 1 year ago.
I think you are going to have an issue with the bypass circuit. How far fluid shoots out of the line isn't very accurate.
Customer: replied 1 year ago.
If u read my messages I stated that I pulled the cooler line off and started the truck that was to see if there was pressure I not sure where this check valve is I'm pretty sure mine is flowing freely but I would like to check it anyway if u could tell me the location it would help . Is there a certain height or pla c e this cooler should be mounted and could the torque converter be doing this ?
Expert:  FSM09 replied 1 year ago.
I'm sorry that isn't showing up on my side of the page. I would mount the cooler toward the middle of the radiator for best air flow.
Customer: replied 1 year ago.
No location of bypass valve it would help thanks
Expert:  FSM09 replied 1 year ago.

The cooler bypass valve is on the side of the transmission. It is a tube that goes from the front fitting to the rear fitting of the transmission.

Expert:  FSM09 replied 1 year ago.

Hello, were you able to get your concern corrected?