Hi All

I recently scored a rust-free 92 740 wagon at auction for $500.

Everything on it works, with the assortment of quirks a 25 year old vehicle will have.

The one big issue is the lake that appears on the drivers side. Leaks are a huge issue since I live in the west coast rain forest. I googled a lot and found a number of postings on this, but none ever provided clear instructions on locating the rear sunroof drains to ensure they are flowing clear.

I have posted this to provide images of the rear drains and other steps I took to (hopefully) eliminate the problem.

First pic is passenger side sunroof drain, accessed by removing cover. In order to clean, I soaked in spray silicone to ease removal, then used a blow gun to clear debris.



I also took the opportunity to clean round the drain plug for this space, and reinstalled that. Volvo has an excellent design for these plugs.

Rinse & repeat for Driver side

Next I blew out the front drains from the top.

There was no significant issues with the drains, so they were not likely the source of the water feature in my car.

Next common culprit is the vent plug in the Driver toe kick panel. I could see water flow stains from this plug, but could not find a way to remove it for re-seal, so I went nuts with kitchen & bath latex caulking.

Pic from driver floor toward left toe-kick


I know a lot of folks would use silicon sealant, but silicon has the drawback that nothing will stick to it, even fresh silicon. If your seal is not perfect the first time, you will never be able to patch it. Latex caulking can be built up.

Now the source for the water that can sneak through here, is the cowl below the windshield. I poured some water in there, and heard the distinct sound of water hitting plastic. Its a lousy pic, but maybe you can make out the flow doing a dogleg toward the back.

Bottom of pic is toward front of car



To divert the flow forward instead of on top of the kick panel vent, I built up a coffer dam using more latex caulk. I can usually do a much neater job, but my hands are too large to fit into the space. What would work better is one of those bathtub splash divert kits.

Pics is from center toward driver side


I won't know for sure until the next downpour, but they are never more than a few days away around here.

 

I vote for the vent flap being the cause--hope you were successful sealing it!

 

Pretty good chance that that is the kick panel vent cover leaking. Too bad you didn't visually see the water dripping down from that vent cover when it was raining. Then you would have a positive verification that you sealed it well if it stayed dry the next rainstorm. But looks like you got it, if your caulking sticks well and filled all the voids. Keep the kickpanel off, and inspect down there with a strong flashlight after the next rainstorm starts, looking for a small trail of water running down from the vent opening. If it stays dry, congratulations! Either that, or that wasn't the source of the leak in the first place.

Good job on clearing the sunroof pan drains.

 

Hi folks

Just a follow-up; poured rain plus sleet & snow for several days

No fresh water inside, so it was worth the effort.

All the snow makes me wish for LSD diff tho'

Anyone with questions about what I did can PM me.

cheers
K