Transmission valve body top connector leak

Post by **FireFox31** » 21 Nov 2023, 19:22

How would you stop a leak at the transmission valve body top hose connector that's embedded in the sheet metal? This is a five speed automatic on a 2000 V70.

When I replaced the transmission fluid return line, I used inductive heat to free the stuck valve body top nut. Now it's leaking despite the hose nut being on very tightly. The connector in the valve body metal is able to rotate slightly. Did it have a rubber gasket which I melted with the heat? Would a bead of high temp RTV around the base help? Or should I replace the entire cover due to rust?

I've read that replacing the cover requires raising the engine a bit and carefully reinstalling the cover without smearing the bead of new sealant. I may try dropping the subframe to replace the rack and engine mounts, so swapping the cover could be done then as well. Still, it's drastic.

abscate kindly provided me the attached pictures of a new valve body cover, part 31259502, which I'm attaching for reference.

Post by **wizechatmgr** » 21 Nov 2023, 21:04

I feel 90% confident that if you can find some AC rated o-rings one will fit and likely work. Volvo loves using o-rings in nearly all fluid connections.

Post by **abscate** » 22 Nov 2023, 04:20

That nut is swayed on so it won’t be fun to get off. Can You get a new cover or are they NLA?

Hmmm, $68 bucks for a new one, vs 2 hours of removing the swage, installing seal.

50-50 call for me , which I would bias to a new part because I’m old and crusty

Harry’s price $35 for the pan, $165 for a whole transmissiony...plus 3 hours of fun in the Mudi and slush fighting it off ...

Hers a thought. With car off, move the shifter so that the linkage is out of the way. Now clean that area thoroughly with acetone. JB weld a bead around the nut to seal the seep from the edge. Use the 24 hour setting one, not the quick stuff

Post by **wizechatmgr** » 22 Nov 2023, 07:52

Another idea would be silver soldering it... Clean with acetone as above or brake cleaner, use acid core solder, sweat it just like a copper pipe. This way it should take some pressure as well as seal.

Post by **FireFox31** » 26 Nov 2023, 11:21

There's definitely a gasket between the outside of the valve body and the threaded connector. It might be rubber, so I question if JB Weld or soldering would properly adhere to it. That's why I thought high temp RTV. I'm pretty sure it's not a high pressure connection.

I'm going to try some RTV and quickly check the result. I'll order a new cover during Cyber Monday sale in case that fails; should be returnable if not needed. I would like to drop the subframe to more easily replace the cover, steering rack, engine mounts, and maybe even rear coolant pipe.