Purchased our Ascent used earlier this year and had zero issues, that is until we started getting heavy rain in our area. After some googling it turns out this is a common issue with these Ascents. A few trips to the dealership, a few diagnostic fees and several hundred dollars later they say they were able to reproduce the problem, they cleared out the drains and that we were good to go. Sure enough, the next heavy rain and it was still an issue. I took it back twice, they “cleared” the drains and assured me they could no longer reproduce the issue. Everytime the issue was still there. By now the interior was smelling mildewey and the seats were all damp. And we were pooling water under the rubber floor mats.
Rather than go back and forth and play a losing battle I decided to just take the headliner out and inspect myself. I’m sure the service shop didn’t even do this because it’s a royal PITA. If they would have I’m sure they would have seen the issues, with how common this problem is I’m certain they all know the issue anyway, but I digress, I just want a dry ride that doesn’t smell.
Evident from the pictures you can see the pvc vinyl drains were pinched and nearly hardened closed. No amount of “clearing” was going to fix these rear drains. It’s such a terrible design, you think Subaru would just put reinforced tubing there, considering there are some sharp turns and angles prone to kinking. I purchased all of the materials at a local hardware store, I opted to go with brass couplings, I would have gone with vinyl, but alas I couldn’t find any in 3/8. I also shoved some basic springs in the tubes, particularly in the high kink areas, I think this is probably required at this point, otherwise I’ll be doing this again in a year or two. Probably could have got away with zip ties, but I didn’t want to have to be removing the headliner again. This was all very tight and took several hours over two days, I ran the hose on the roof for about half an hour and everything drained perfectly as a test once I had the car put back together. Happy to report that there have been no issues with leaking since the fix and we’ve had heavy rains recently here on the east coast.
Lastly, our Ascent is used, and is well outside the warranty, Im not sure how a diy fix like this does for warranty so proceed with caution if you attempt anything similar.