Transmission cooler Line
 

I picked up an early 94 7.3 IDI F350 with 129k miles , Nice solid truck , i been doing major TLC to make it road safe as it sat for long time.

i know from the owner that it had Tranny fluid leak , Tranny shift fine during the short drive to bring it home but loose fluid fast , After inspection i discovered the the leak is not coming from Tranny it self or it's housing , It's coming from the the cooling lines as the lines ( Out and return ) covered by fluid mid way near the right wheel well at least that is what i saw and hoping for .

I called my local part stores to get lines but they don't show them in their system . Does any one one the best after market solution or where to get these line . Or i have to get them from the Stealership


I am going to investigate farther more into it today

not availably anywhere. you need to make them out of steel fuel line. if i remember correctly, they are 3/8 line.

they're 5/16 line oem.they didn't become 3/8 until the name change to 4r100.however 3/8 lines is an upgrade that wont hurt anything.there's a bit more to perform the whole upgrade but no point in details unless interested (not an upgrade worth anything imho unless you upgrade the internal pump to the '95+ high volume.)
in summary.either or 5/16 or 3/8 will do the trick.good luck.hope that's all it is.:-X22

Get some 5/16" brake line and bend your own.:-X22

It was a long afternoon but ended up with great result , Resealed all injectors, New fuel /Water filter , Fresh fuel , primed all the lines and we got nice running 7.3 IDI with Zero diesel leak .

Make sure you disconnect the ground if you ever get to work on any of these suckers and have to remove the glow plug relay or the (hot ) lead will touch something ,ask me how do i know


Added more ATF fluid and without even the Eng running i discovered pin hole on one line and the 2nd shaved from rubbing on the one is leaking , the leaky lines coming from the area near the starter . I guess the pressure increase inside these lines when the internal valves inside the transmission move

I wont be town heavy at all , All will be Hwy driving and loaded bed . Should i cut the bad section and use rubber ATF hoses or what is the best solution than re do it all

I also have Sidewinder turbo by banks Power in place , With single exhaust Gauge inside , Where can i get the triple gauges set up to monitor boost , exhaust , Tranny Temp ..Etc

when mine sprung a leak, i replaced the complete line for piece of mind.

You could cut and patch the lines to get you by for now.
I would replace them with new lines as soon as possible.

I agree with you , How long is these lines , I have access to small pipe bender .Is 5/16 or 3/8 is the one i need

How to get the fitting on the new lines from the transmission side , Can i remove the old ones/ Do they slide out ?

they screw into the trans and radiator.

Yah i know they screw in place , I was just curious if i could use the old ones but i found out the new steel lines comes with them, However i have to take my old line to match the ends that goes to the transmission

Would it be the best time now to go for bigger lines like 3/8

You would need to adapt it up to 3/8 at the trans and radiator, so you'd still have the restriction there. I'd just run 5/16 line

i replaced all Tranny lines with 5/16 steel lines . Truck is fluid tight and she's running great . Thanks every one for helping me out

with the above lines being new i started to drive the truck and noticed another issue with the ATF coming out from the bell housing when it reaches the Op temp .

Most likely Pump seal or bushing need replaced along with the seal, So the truck at the shop to get the tranny pulled to replace the $8 part and hope that the TC grooved neck is good .

Due to the weigh of this giant Tranny , no access to heavy duty trany jack i choose to send it to the shop as much as i hate it . I am going to install the Big 6.0 Tranny cooler or after market large cooler any thing else to keep in mind

Sounds like youre pretty well on top of things. One more thing to consider is a tugger shift kit, since you already have it at the shop and its pulled, wouldnt take much to put it in while the fluid is dropped. A good converter would help as well, but are pretty spendy. Maybe someone above can chip in on how much theyre really needed at stock power level.

Yah shift kit sound pretty good mod but I have to budget for it , Maybe next ATF service i will do that my self .