This was for my 1992 Range Rover classic.

Backstory: I just finished putting in a newer engine, trans, and transfer case and on it's first offroad voyage after the work about 300 meters from the end of the trail the transmission cooling line between the transmission cooler and the radiator started leaking. We were able to get some fusion tape on it and limp it to the end of the trial where I later that day returned with trailer and towed it home. Upon searching around and even talking to Atlantic British and the dealership I have found out that not all 3 of these lines are available anymore. Figuring this is 25 year old hose I wanted to replace them all and never see this trouble again. So I needed to come up with an alternative using AN line. It's my understanding the system works by pumping fluid from the trans to the transmission cooler (hedgehog) then from there to the top of the radiator (driver's side) then out from the lower radiator (driver's side) and through the tee with the sensor then back to the transmission. It does this to first cool the fluid as needed, then heat the fluid with engine coolant then send it back to the transmission. This keeps it at the correct temperature in summer or winter. The sensor is to detect the fluid is 140F and enable overdrive in the transmission.

Parts Summit Racing:
-20' RUS-632090 AN6 line braided line
-2 RUS-670533 M16x1.5mm to AN6 straight adapter (transmission fittings)
-4 RUS-610165 Hose end non swivel 90 degree AN6 (2 on radiator and 2 on transmission ends)
-2 RUS-660463 3/8" NPT to AN6 straight adapter (radiator fittings)
-2 RUS-610095 Hose end non swivel 45 degree AN6 (transmission cooler aka hedgehog fittings) Could also use 90 degree fittings
-2 RUS-610025 Hose end straight hose to female AN6
-1 RUS-661253 Fitting 90 degree flare bulkhead AN6 (Used to drill and tap to hold trans temp sensor)

Parts PegasusAutoRacing
-2 3252-8-6AN 1/2" BSP to AN6 swivel adapter straight (needed for trans cooler fittings aka hedgehog) These were the tricky ones to find.

Drill Size Q or 21/64"
Tap M10x1.5mm bottom tap


So one challenge was the radiator to transmission line that has the trans fluid temp sensor mounted inline from the factor in a Tee crimped to the hoses. This is the one you cannot seem to buy anymore. To solve this I used AN6 line out of the bottom of the radiator to a 90 then straight into the bulkhead 90. In the corner of the 90 I drilled the 21/64" hole after marking the spot with a center punch then I gently hand tapped the threads at M10x1.5. I then used teflon tape on the sensor and screwed it in.

Lay out the sensor line.


90 degree bulkhead fitting with sensor drilled/tapped/and screwed in


Assembled sensor line.


AN6 to 1/2"BSP swivel adapters with 45 degree hose ends installed on hedgehog transmission cooler.


Hedgehog/Trans cooler lines installed. I still used the hold down clamp under the radiator to secure these. You do need to take the radiator brackets loose and lift it to get to the clamp and run the lines. I didn't disconnect the coolant or oil cooler lines though. I was able to do this solo.


Here you can see the adapter to 90 degree hose end going down. This is the hose from the end of the hedgehog/trans cooler.


This image shows the lines with sensor before I put the fan and shroud back in place. I used the two clamps on stand offs that run along the oil pan to hold the lines just like the hard lines were mounted.




A few things I learned. The upper transmission line and fitting are a pain to reach and get loose. I ended up cutting the line with a Sawzall and unscrewed it that way as I could not hold the line and the adapter in the trans and it all spun together winding up the line around itself as I went until the adapter fully unscrewed from the transmission. This was the toughest part of the whole job. The lower line and adapter went pretty easy. That like could actually be left in place as it does have a fitting just to the driver's side of the crank pulley at the end of the oil pan (look under to see it). You could just get a 3rd 1/2" BSP female to AN6 male swivel adapter and put it there instead of one of the M16 x 1.5mm to AN6 adapters. That's up to you. I also used one heavy zip tie to help ensure those lines don't want to migrate over toward the crank pulley. They didn't look like they wanted to anyways but I wanted to be sure. The line assembly itself is super easy and this was my first time using AN line. I really like it. The previous owner had used AN line for the oil cooler/adapter plate to radiator connections and they are perfect.

I can now keep a 5' leftover piece of AN6 line in my spare parts in the rig coiled up tightly and taped in the event any of these 3 lines breaks I can use it to make up a new line. The fittings can be reused.

 

nice work !