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73-87 Chevy _ GMC Trucks => Interior & Equipment => Topic started by: K20Wulf on February 03, 2010, 04:40:46 PM

Title: Cab leaking :(
Post by: K20Wulf on February 03, 2010, 04:40:46 PM
Ok, so I have water coming in on the passenger side (it pools up on the floorboard). It seems to be coming down from somewhere on the left side of the heater core box. But it's not the heater core. It rains a lot here, lol. But I can't seem to figure out where it's getting in. Are there typical places to look? The previous owner pulled out all the air vents and the hoses and all, don't know what that might have done. Help please!
Title: Re: Cab leaking :(
Post by: Layne on February 03, 2010, 04:54:16 PM
http://forum.73-87chevytrucks.com/smforum/index.php?topic=12521.0
Worth a shot... See if it's rusty
Title: Re: Cab leaking :(
Post by: frito-bandito on February 03, 2010, 05:29:12 PM
Does the truck have clearance lights on the roof, if so, they are notorious for leaking, especially if they aren't factory installed.
Title: Re: Cab leaking :(
Post by: K20Wulf on February 03, 2010, 05:35:44 PM
Does the truck have clearance lights on the roof, if so, they are notorious for leaking, especially if they aren't factory installed.

No clearance lights. I'm going to check the cowl as soon as I get a dry day. It's not a huge amount of water, but I want to get it stopped. Thanks guys :)
Title: Re: Cab leaking :(
Post by: frito-bandito on February 03, 2010, 06:18:17 PM
Ok, then definitely check for rust, good luck
Title: Re: Cab leaking :(
Post by: 78 Chevyrado on February 04, 2010, 05:30:16 PM
Sounds like rust...  also check your rear hood to cowl seal.  if it's bad water can drip down onto the heater box under the hood.  this isn't a big problem unless the seals from the box to the cab are bad.  I had that in my '78 and it was a bad hood seal combined with the AC box sealant being bad.
Title: Re: Cab leaking :(
Post by: K20Wulf on February 05, 2010, 02:36:20 AM
Sounds like rust...  also check your rear hood to cowl seal.  if it's bad water can drip down onto the heater box under the hood.  this isn't a big problem unless the seals from the box to the cab are bad.  I had that in my '78 and it was a bad hood seal combined with the AC box sealant being bad.

Well, so far no let up in the rain, plus I've been sick the last couple days. The cowl seal isn't in bad shape. Do you mean the box that houses the heater core? Or something else? There is no (heater) box on the passenger side of the cab and I can see the fan from the inside (make sense???). All the "plumbing" for the vents was removed by someone. So not real sure what else they removed.
Title: Re: Cab leaking :(
Post by: 78 Chevyrado on February 05, 2010, 12:18:54 PM
Sounds like rust...  also check your rear hood to cowl seal.  if it's bad water can drip down onto the heater box under the hood.  this isn't a big problem unless the seals from the box to the cab are bad.  I had that in my '78 and it was a bad hood seal combined with the AC box sealant being bad.

Well, so far no let up in the rain, plus I've been sick the last couple days. The cowl seal isn't in bad shape. Do you mean the box that houses the heater core? Or something else? There is no (heater) box on the passenger side of the cab and I can see the fan from the inside (make sense???). All the "plumbing" for the vents was removed by someone. So not real sure what else they removed.

Yeah it's the box housing the heater core and the blower fan.  If there's nothing there at all I'd bet on that being the leak.  It can also leak where the heater core fitting stick through the firewall.
Title: Re: Cab leaking :(
Post by: K20Wulf on February 05, 2010, 01:21:03 PM
Yeah it's the box housing the heater core and the blower fan.  If there's nothing there at all I'd bet on that being the leak.  It can also leak where the heater core fitting stick through the firewall.

The box for the heater core is there, just not the one for the blower fan. I'm not sure what it's all supposed to look like under there, been awhile since I owned the last Chev.

I'll try to get some pics up later. So you can see what I'm talking about.
Title: Re: Cab leaking :(
Post by: K20Wulf on February 06, 2010, 06:01:40 PM
Hopefully these will be good enough. :)


(http://i701.photobucket.com/albums/ww17/Wulf/86%20K20/Interior%20pics/Photo0026.jpg)

(http://i701.photobucket.com/albums/ww17/Wulf/86%20K20/Interior%20pics/Photo0025.jpg)
Title: Re: Cab leaking :(
Post by: mrboyy17 on February 07, 2010, 10:47:24 AM
put a blower motor in the hole.  maybe a new fan blade too if that one is bad.  you can pick up these blower motors brand new for 25-40 bucks
mark
Title: Re: Cab leaking :(
Post by: K20Wulf on February 07, 2010, 01:22:59 PM
put a blower motor in the hole.  maybe a new fan blade too if that one is bad.  you can pick up these blower motors brand new for 25-40 bucks
mark

There already is a blower motor, and a fan. That's not where the water is coming in.
Title: Re: Cab leaking :(
Post by: mrboyy17 on February 07, 2010, 03:27:03 PM
sorry that is the inside of your cab right?  i thought at first i was looking at your firewall cuz i see the blower fan.  i dont know why there is a huge hole there in your cab
Title: Re: Cab leaking :(
Post by: ccz145a on February 07, 2010, 03:41:57 PM
That whole cavity is open above to the cowl area. What keeps the water out is a seal around the opening in the kick panel. As long as the kick panel is missing, the water will come in.
Title: Re: Cab leaking :(
Post by: K20Wulf on February 07, 2010, 04:13:44 PM
That whole cavity is open above to the cowl area. What keeps the water out is a seal around the opening in the kick panel. As long as the kick panel is missing, the water will come in.

The water doesn't really seem to come in there. It looks to be coming in above the heater core box somewhere. Also, I had a bit come in on the drivers side, though I'm not sure from where. Maybe the cowl area is leaking and the cowl seal on the hood should be replaced.
Title: Re: Cab leaking :(
Post by: jaredts on February 07, 2010, 08:53:17 PM
Dude check under the cowl panel as soon as you can.  There's seam sealer on a seam there at the top of your firewall that is known for leaking.  It can also rust away the top of the firewall and its not an easy place to get into and fix.
Title: Re: Cab leaking :(
Post by: K20Wulf on February 08, 2010, 01:04:15 AM
Dude check under the cowl panel as soon as you can.  There's seam sealer on a seam there at the top of your firewall that is known for leaking.  It can also rust away the top of the firewall and its not an easy place to get into and fix.

I'm going to pull the cowl tomorrow. Hopefully there won't be any rain.
Title: Re: Cab leaking :(
Post by: frito-bandito on February 18, 2010, 08:37:40 PM
Dude check under the cowl panel as soon as you can.  There's seam sealer on a seam there at the top of your firewall that is known for leaking.  It can also rust away the top of the firewall and its not an easy place to get into and fix.

I'm going to pull the cowl tomorrow. Hopefully there won't be any rain.

So... what'd you find out?
Title: Re: Cab leaking :(
Post by: K20Wulf on February 22, 2010, 11:08:27 PM
Sorry, it's was raining the next day and I haven't pulled the cowl yet. I'm pretty sure it's the hood to cowl seal that is bad.
Title: Re: Cab leaking :(
Post by: birdy411 on February 23, 2010, 12:54:52 PM
I didn't read above so I don't know if someone else suggested this or not...

Make sure your heater hoses are backed off the heater core a little. You don't want them jammed up into the cab, and make sure that those clamps are super tight.
Title: Re: Cab leaking :(
Post by: Toms88 on June 13, 2010, 09:31:05 PM
look around the window rubber where the A piler meets the cowl. is a problem also. mine stared leeking there i just remove dash pad and used water hose on the out side ran water down corner and found leek so used compressed air to dry and used windsheid glue (the black stuff they us to install windsheids) stoped leek
Title: Re: Cab leaking :(
Post by: K20Wulf on January 13, 2011, 02:12:48 AM
Reviving this one after a long time.

I finally found out where the leak is and it's not good. At the top of the firewall inside the cab there are spots where it's slightly rusted through. Enough to let the water trickle in. Looking into the cowl area from under the hood I can see there is a lot of rust. What would be the best way to fix this? Cut out all the bad metal and weld new in its place? If so, this is not a job I can do. Anyone have the slightest idea what it would cost? Is cab replacement a cheaper option?  ???
Title: Re: Cab leaking :(
Post by: GUITAR1989 on January 13, 2011, 03:10:37 AM
Hmm well u definitaly want to stop that rust. . If it isnt to bad maybe you could just get some anti rust paint like POR15 and prep the metal and seal it so no further rust damage can occour then use some kind of body filler to fill in the holes and paint over it. Ive never dealt with wicked rust so u may not wanna go that rought. might be better to have it cut out and have new sheet metal welded in.

also man that big air vent hole where the panel is missing will let water in. I was actually just cleaning my cowel out today and found out i can stick my arm down the passenger side of the cowel and put my hand right through the hole in the cab where that panel goes. when i sprayed water in the cowel I cound see it just running into my cab through that hole. Im gonna be sealing that sucker with some silacone when the rain lets up :P
you might wanna put some saran wrap over it and tape it closed until u can get the panel.

Hope this helps you :)
Title: Re: Cab leaking :(
Post by: jaredts on January 13, 2011, 07:05:09 AM
At that point cab replacement might be best, although it could be fixed.  This is a big project.  I don't know how bad the rust is, but you could buy some time by wire brushing and treating with rust stopping paint/primer and putting seam sealer over it from the cowl access holes.  If you get the seam sealer on there beyond the rusted areas to form a seal so no more water gets in it might last a little while.  I can't say for sure without seeing it.  Maybe someone else has some pictures of a repair of this area.  Mine had a couple 1/4" or so holes and for now the method above has kept mine water tight.
Title: Re: Cab leaking :(
Post by: K20Wulf on January 13, 2011, 01:33:11 PM
Thanks guys. It's going to be a pita no matter what I do. We're in the middle of rainy season out here, so I'll be lucky to get a dry day to work on it. As far as I can tell it's only leaking in a couple places. I should be able to seal them up as a temp fix. I'm not sure what the sheet metal work would cost, as I would replace as much of the rusted metal as possible. Cab replacement seems like an easier route, but I wonder how much a good junkyard cab would cost.
Title: Re: Cab leaking :(
Post by: chevyh20 on January 13, 2011, 08:51:33 PM
i had a blazer with the same problem. It is a big job to do. I completely took apart the dash to avoid fire or damage to sensitive parts with welding. i think it is a cab off repair as that is how i had mine. i can't imagine being able to do it otherwise. Mine started from leaky seam sealer in the cowl. So at least get that cowl sealed so the water will not leak down the firewall and inside your cab.
Title: Re: Cab leaking :(
Post by: K20Wulf on January 13, 2011, 11:00:11 PM
I think I'm going to get a some type of sealer and a wire brush this weekend. Will clean up the area's where it's leaking as much as possible and seal them up. I know it will only be a temp fix, but I can't afford to take the truck to a body shop right now.
Title: Re: Cab leaking :(
Post by: bake74 on January 14, 2011, 11:03:12 PM
     you really can't make out by the pic's you posted, but you said the p.o. ripped all the hoses and vent tubes out.  I would start by looking those area's over and comparing to other trucks or pics you can find.  Sounds like the p.o. started something and never finished.
Title: Re: Cab leaking :(
Post by: K20Wulf on January 25, 2011, 04:05:11 AM
It's fixed. Had to split the repair up between a couple days because of the rain, but it's done and no leaks. Was a pain to get in the cowl to chip out the old sealer and sand and vacuum out all the mess, lol. But it was worth the work. Thank you everyone for your help!  ;D
Title: Re: Cab leaking :(
Post by: jaredts on January 25, 2011, 10:38:29 AM
It's fixed. Had to split the repair up between a couple days because of the rain, but it's done and no leaks. Was a pain to get in the cowl to chip out the old sealer and sand and vacuum out all the mess, lol. But it was worth the work. Thank you everyone for your help!  ;D
I know what you mean.  Those openings are way too small to do a perfect job.  I couldn't get seam sealer all the way to the point that it curves down on mine, but did the best I could.  Mine hasn't leaked yet.
Title: Re: Cab leaking :(
Post by: K20Wulf on January 27, 2011, 03:12:30 PM
I know what you mean.  Those openings are way too small to do a perfect job.  I couldn't get seam sealer all the way to the point that it curves down on mine, but did the best I could.  Mine hasn't leaked yet.

The way I got it all the way down the curve??? I put a huge glob of sealer on the end of a long flathead screwdriver and basically pulled it towards me along the seam. It wasn't pretty, but it worked great! lol