Water leak...into spare tire area etc

Thanks to everyone for this thread.

Water collecting under my 12V battery and under my spare tire was gradually getting worse. My Prius is a 2005 gen 2 with 107k miles. Until I read this thread I had no idea how all that water was getting into the car. At times the spare tire area looked like a swimming pool!

After reading this thread I identified the typical cracks where the rear end of the rain gutter channels meet up with the rear hatch area. In my car there were thin cracks on both driver and passenger side which were about two inches in length.

I got the “flowable silicone sealer” and applied it to the cracks.

There was a very hard rain the next day. I didn’t find any water inside the car at all afterwards.

-Greg

 

I have leak in battery well only. Not real keen on all the effort to try and seal it since it seems to not be huge. I’ve read about pulling the plug, but it is not clear if that is just to drain the water, or if it should be permanently removed. The car is not garage-kept. It’s also maybe going to Ann Arbor soon so maybe face longer stretches of all out cold than it’s used to here in the Delaware Valley. Any advice appreciated.

 

-im assuming you havent found the exact source location of the leak yet- but I guess you can pull the plug and let it continually drain out, but if your gonna do that why not just remove the paneling around the battery and see if you can find the leak (unless the leak is actually from some hole near the battery well). How I did it: Pull the back seats down and after you remove the fabric paneling to expose the interior metal of car, hose the outside of the car around the battery nice and wet and then go back in from the rear doors and look for the leak. I found my leak coming actually from the tail light mounting holes.

 

Hello, I found a leak today, after some rain, in my newly purchased 2009 Prius. Not pooling in the spare tire well, but still noticeable, with trim panels on the driver side soaking wet. I will inspect the roof seams tomorrow. I too have never seen cars leaking like this, maybe its a feature of this body style. Anyway, I wanted to thank everyone for the thread, as I can now get to the puppy who refuses to shit outside and other life problems.

 

Yesterday, after taking the rear bumper cover off my '04, I finally found this "new" leak. This spot was leaking on the passenger side, and clearly "showing signs" on the driver side as well. Sealed both sides. The ones above by the rain gutters were sealed years ago.

 

I took half my 2008 apart because of this. Wouldn't start, had HV fan error and a few others. Finally tracked it down to a connector with the green nasties on the passenger side rear quarter. Also had the water in the 12v battery area. I'm definitely sealing those up this weekend.

 

Also had to do the same things on my 2008. Caulked both gutters on the roof. Then all the seams and little cracks around the hatch hinges and arms. No water in the 12v compartment or sp wheel well. After checking my repairs after heavy rain I found some more:

Water was coming in on the drivers side through the cracks and dripping via channels onto the trim soaking it. Eventually ended up on the brackets securing the strap down anchors and then into the driver side compartment. But this dripping was minimal.

On the right side it had dripped down the cooling fan and further down the channel onto the bracket holding the brake module assembly.
The driver side leak was discovered today. I noticed moisture at the rear seat. (Where the HV wires go to or from the battery, left seatbelt is mounted here too.) This could’ve come from the left side trunk channels. Couldn’t find any other cracks or holes during my inspection. Check this area thoroughly, I had slight mold accumulation.

Also the driver side pressure vent had water on the film shutting it. I have no clue where that came from, couldn’t find any water streaks. This did not enter the car, I suspect it could’ve been splattering from the wheels?

To be continued… I’ll do regular checks. I’m a new member and I think I can’t upload photos yet. If anyone’s interested in photos I can work something out.

 

I know this is an older thread. I’m reading thru it. I can’t tell where the water leak is coming from. I’m going to attach pics. The water shows up under the spare tire and in the small area below the driver’s side tail light. Looks like it’s initially coming from somewhere along the drives side. No signs of water around tail light although I don’t have the ability to take it apart. None of the fabric pieces are wet. I removed the water under the spare tire before thinking to take pic. It’s wasn’t an huge amount but takes a minute to drain out. Any ideas how to diagnose this? I don’t have the skill or tools to take things apart any further than this. I’m seeing posts on a FB page where two people with Gen 5s have rust in this area already from what looks like a faulty paint job. Thanks so much!

 

Well I found another thread with great photos explaining where to look. Found the cracked area at the top of the hatch drain area. Hopefully that’s the only leak. Will be trying the flowable silicone as soon as I can find someone to help me apply it.

 

Through The Roof! Elastomeric Roof Sealant, Brushable, Clear - Google Search
Maybe try the sealant I pasted above.

I used GE silicone on mine and while it worked well, it was really lacking in looks, if you get my drift.

I later found Through the Roof while I was sealing some household rain gutters. Used it on a friend's Prius and it was simple to work with, did a tidy job and worked.
kris

 

As long as we clean the surface well with Isopropanol or brake cleaner, any good silicone or JBwelder will work well

 

Thanks so much! I was looking at the Flowable silicone because I was hoping I could get it to seep into the cracked area. This brush on product is easy to get into a small crack? I want it to look as good as possible.

 

My only gripe about through the roof is the price. When I purchased a jar it was $19. As you can see, the price went up.

The "jar" is in the form of a somewhat thick liquid. Maybe like a cross between honey and maple syrup, but edging to the thinner liquid. At least that's what my jar held. Easy to brush.

I also used it to "glue down" a shingle I accidentally ripped off a roof. Been five years no leaks there either. And, yes, my doctor did tell me NEVER TO CLIMB LADDERS AGAIN.

Be aware of a few things. As it ages and is exposed to sunlight, it gets a bit yellowed, but GE Silcone changes also.

If, you are careful, you can likely do a good job with silicone in a tube for a lower cost.

So that's a factor.

But my GE work kept out the water, but looked as if a five-year-old had applied. REALLY poor.

In my defense, I was recovering from a near fatal auto wreck when I did it and my whole body was shaky.

My friend's car looked great.

So the usual cavets. You are not me. What I recommend, while it worked great on my friend's Prius, may not work on yours. Etc., Etc.

Read the web reviews. Make up your mind. It's an easy fix no matter which path you take...it's the looks afterwards that can be tricky.
kris

 

Thanks for these details. Really appreciate the help. The goop that’s all along the edge of the spare tire area looks like someone slapped it on with a popsicle stick. I’m good with detailed work so I’m pretty sure I can do a decent job. It’s the chemical smell I can’t handle so I’ll ask a friend to help.