Resealing A/C Box

[86Cutlass383SR]

I think before I completely install my front fenders and hood, I should probably think about resealing the a/c box on my firewall. The car's not yet drivable but I'm getting some water seepage from somewhere. It will be getting a new windshield and new door seal after it's mobile again. The only thing left would be the a/c box. The hole for the ecm wiring is sealed, too.

I've never had the box off a car so I need to know where all the bolts are. Also, what do you guys use to reseal it with? Does it have to come completely off or just loosened and pulled back. How big a job is this? Can you just run a small (neat) bead of silicone around it and seal it?

This will be a daily driver and driven in all weather. I don't want it leaking and rotting my floor boards or new carpet (when I get one).

Thnaks for any ideas.

 

[FE3X CLONE]

I had to reseal my mom's '88 CSCB box after I did a heater core replacement because it was leaking.

What you need is 3M Strip-caulk:

http://www.allbatterysalesandservice.co ... 4,410.html

It's pretty much the same thing the factory used.

 

[86Cutlass383SR]

Not to sound stupid, but, did the whole box have to pulled away from the firewall? I'd assume not since you did it to a running car, meaning you didn't pull the fender to get the box off the firewall...

 

[FE3X CLONE]

No. The top of the box will separate from the lower half.

 

[DrRansom442]

BTW, my $.02 - do your heater core now. Sounds like everything is apart and would be 10 times easier to do .... especially if you are resealing the box. I have seen O.E.M. seals for the box on Ebay. A heater core is a whooping $19.99.

 

[Bonnewagon]

Agree on heater core-you just know it will leak as soon as everything is bottoned up. The strip caulk is good, as is marine caulk like Boatlife or 5200 just make sure the old stuff is all off. I did mine without removing the fender and missed a tiny spot down where I couldn't see what I was doing. Yup, it leaked. Took weeks to find the damn leak and I was able to just smear some Boatlife over it and it stopped. Oh, and if it's not coming off easy, don't yank it, you probably missed a screw.

 

[DrRansom442]

Agree on heater core-you just know it will leak as soon as everything is bottoned up. The strip caulk is good, as is marine caulk like Boatlife or 5200 just make sure the old stuff is all off. I did mine without removing the fender and missed a tiny spot down where I couldn't see what I was doing. Yup, it leaked. Took weeks to find the damn leak and I was able to just smear some Boatlife over it and it stopped. Oh, and if it's not coming off easy, don't yank it, you probably missed a screw.

X2 don't yank on the lid. I broke mine in like 6 places - missed 3 screws. I liked to NEVER found a replacement.

 

[FE3X CLONE]

Agree on heater core-you just know it will leak as soon as everything is bottoned up. The strip caulk is good, as is marine caulk like Boatlife or 5200 just make sure the old stuff is all off. I did mine without removing the fender and missed a tiny spot down where I couldn't see what I was doing. Yup, it leaked. Took weeks to find the damn leak and I was able to just smear some Boatlife over it and it stopped. Oh, and if it's not coming off easy, don't yank it, you probably missed a screw.

X2 don't yank on the lid. I broke mine in like 6 places - missed 3 screws. I liked to NEVER found a replacement.

X3! lol I was having a time with the one on the '88 and being such a low mile, original car (51,000 miles) I'm very cautious about how I take things apart but this thing was giving me fits. Sure enough, GM like to hide the screws everywhere on those darn things!

You'll know when all the screws are out because it will lift right off.

 

[86Cutlass383SR]

I had always assumed guys were talking about removing the complete a/c box from the firewall to reseal.

Yeah, before I get it all put together I'm replacing the heater core and checking the A/C evaporator core. And the lid will be "resealed" LOL ...

 

[razor376]

I didn't have my box apart but I had all the cowl trim off so I just resealed all the edges I could get to , I took a gasket scraper and removed all the factory sealer off and used 3M windshield Urethane in a tube with a caulking gun and resealed it , the g-bodies are known for for passenger side leaks from these and the make sure the drain flap area at the bottom is clear . Don't use silicone it won't hold up and I also removed the screws that are most exposed when the cowl trim is off and put a small bead of urethane sealer around the shoulder of the head of them before reinstalling them .