jreed » My upper transmission hose developed a leak several years ago (at ~130k miles). It showed up as a slow seeping of ATF from the lower crimp, large enough to keep the metal line below the crimp wet with fluid.
The upper transmission hose is apparently the less common one of the two hoses going to the transmission to develop a leak, but I’m not the only one who has experienced it.
I am grateful to the advice that was posted here about transmission hose leaks, parts sources, repair options, and how to replace leaking upper transmission hoses.
In the photo below you can see the two hose clamps I installed a while ago on the crimp to try to slow down the leak — the hose clamps did not have any effect. The photo was taken after removing the battery and the battery tray (and disconnecting the cruise control pump under the tray), which was helpful to get access to the hose. Overview of area after removal of battery and tray
After keeping an eye on the leak for a while and worrying about it, I decided to go for an OEM replacement hose, mainly for peace of mind. I figure if the leak became large it would allow all or most of the fluid to leak out while the car was running and then potentially allow the transmission to overheat or be damaged… an expensive problem. The Volvo replacement hose cost about $90 from Waltrip including shipping. Note that this hose is the AT fluid outlet hose: it connects to the lower part of the transmission and the upper part of the radiator.
The part number is 9180542 (note this is the part number for model years up to and including 1998) Upper transmission hose part 9180542
The first step is to clean up around the top and bottom hose connections and the nearby areas so you avoid getting any dirt into the transmission. Then I used a pair of snap ring pliers to remove the clip. These little pliers made the job a lot easier than prying with a screwdriver or using needle nose pliers (both of which I have used in the past when doing fluid changes).
Clip removal with Snap Ring Pliers AT_hose_clamp_removal_2.jpg
Once you get the clip off at the top, the upper hose will pull straight out from the radiator.
Upper hose loose
Next you have to remove a bolt that holds a support clamp about half way down the solid metal part of the line. This bolt is difficult to reach. From below the car I used a slim flexible wrench with a 12mm 6pt deep socket to break the torque and loosen the bolt. Once it was loose I removed it with the finger tips on my left hand, which could just barely reach between the subframe and the transmission. If I had to do it again I would break the torque from below but then loosen and remove the bolt by reaching down from above in the engine compartment.