Hi, I did not know how to delete my original thread about "the plastic trim piece around back window". It did not fully address what I was looking for. So, I hope I do not get in trouble for posting this new thread .So, I bought a 2000 ford f150 extended cab xlt. After buying it I noticed a leak in the back window. I turned to this forum for advice on how to fix the problem and like always the great people of this forum led me step by step on how to fix the rear window leak. I removed all the interior trim pieces, removed the nuts from the window frame, and cut through the old factory seal to remove the rear window. I scraped and cleaned all of the old glue from the window frame and cab. I re-caulked the window frame following the pattern on the rear window with 3M window weld. I re-installed the window, put the nuts back on a, and re-installed all the trim pieces. About a week later it came a heavy rain and the window leaked more than it did before I re-sealed it in the same place as before. I applied silicone to the top of the plastic trim piece that goes around the rear window and also around the outside of the rear cab brake light. I ran a water hose over the window and it seemed to fix the problem.

It has been raining pretty much every day for the past couple of weeks where I live and my truck stays parked outside. Well a few days ago I washed and waxed my truck. The next day I go to clean and vacuum the interior. I noticed underneath the passenger side floor mate the carpet was soaking wet. I took the trim pieces off and pulled the carpet back it revealed that part of the floor pan was rusted through where water had been seeping in. I put the water hose around the door molding and waited to see if there was water leaking in. There wasn't any. I put the water hose all over and around the back glass to see what would happen. The water was dripping through the window (exactly where it was before I re-sealed it in the beginning) going down the rocker panel and pooling in the front floor board. It must have been doing this for years to rust part of the floor pan completely out.

This weekend I took the back window back out. Cutting through the 3M window weld was "Tough". It took me two days to un-seal the back window. After doing that I knew that there was no way water was leaking through that new seal (At least that is what I think).

After I removed all the interior trim pieces. I had someone soak the back window while I was in the truck and I could clearly see it leaking through the seal on the passenger side right top just as it did before I re-sealed the window. The truck is in great shape mechanically and cosmetically with low miles. I would like to fix the truck right and keep it.

My question is where else can this water be coming from. I do not want to fix everything re-seal the window just to have it leak again. I found some things on the net such as the window frame could be cracked (they said it was made of plastic. Felt like metal to me). Or the gasket on for top mounted brake light could be the cause. I kind of ruled that out because when the water was sprayed heavily on the window and I was inside checking for leaks I did not find any water coming in from the top of the cab. Maybe I just screwed up the re-seal the first time. But cutting through that window caulk was so difficult and time consuming I figured nothing could get through that.

Any comments or suggestions would be greatly appreciated.

Thanks,
brc

 

My son's 1998 Extended Cab XLT was doing the exact same thing. Replaced brake light gasket (very brittle by the way, but not leaking). When water was sprayed on the window itself, you could see it come in on the upper passenger corner of the cab. We had it re-sealed twice......neither worked. Ended up having to buy a complete window and frame. Three years ago, in Houston Texas area, was about $450.00 installed. The old (and new) frame is aluminum I believe, and it just broke from vibration and age I believe.

 

Well I just went outside and inspected my window. It is indeed a plastic frame. Upon inspecting it I am going to have to get a new back glass. I messed and gouged the frame up so bad trying to break the new seal. I called an auto glass shop I deal with and they said it would cost a $150.00 for the glass and to install it. But I am sure the glass they use will be from a salvage yard. They said they had 2 in stock.