When I washed the rig last weekend, tons of water came in through my firewall grommets.
I have a lot of wires in them, so the water just poured in from me spraying under the hood to get rid of the pine needles that have been gathering there since October.

What is correct silicone type to use on the outside where the grommets are on the firewall?
I need to seal it up soon.
My Husky floor mat was soaked underneath, and I can push on the carpet and water comes up

 

Corey,

I have used the Kragen's special RTV black silicone sealant with plenty of success (blue packaging). It's easy to apply and lasts a while and a tube of it is about 3-4 bucks. It's fairly flexible - but definitely protects against water and holds up well to road grime.
Since my rig is a 2WD - i don't have to hose off the undercarriage too much - so hopefully someone else can chime in in case there is something better.

RTV also has a black rubber sealant which looks interesting but is about twice as much. It's supposed to be more flexible, but I don't plan on putting more holes in the firewall anytime soon.

My cable running has been due to audio cabling, but should suffice for your application. I coupled the sealant with the plastic split-loom tubing to deflect water from running down the cables as much as possible.

Hope this helps!

Pete

 

I would just get a tube of the regular household silicone that's used to seal up windows. That way you'll know it'll be waterproof. I'm not sure if it'll stick to metal or plastic though, so check that out.

 

I used sensor safe silicone just because it's what I had lying around and it's held up fine so far.

 

two words:shoe goo

 

Thanks guy's, I just picked up some black hi temp RTV silicone a bit ago.

I had to take out my Husky floormat last night and let the carpet dry some, as it is still very wet, and stinks bad.

No silicone
Hole is very open, and you can see how the water traveled down the wires into the interior.

After silicone
Great gobs of goober!
I squeezed a ton of stuff into the hole itself, and coated the wires real good too.

 

Corey,
As far as the RTV, what you got will work fine. When you go to put it on, try this: Pull the wires back thru the fire wall as much as you can (shouldn't need more than say 1/2 ") goop the RTV around the wires really good and push or pull the wires back thru. Then seal up around the grommet with a little more RTV. By pulling the wires back thru a little this will allow the RTV to seal on the inside of the grommet better.

As far as the water in the carpet. See if you can find one of those self serve carwash places that has the carpet shampoo machines. That should help in not only getting rid of the smell but will also suck the water that is left in the carpet out. Or use a shop vac and some fabreeze in a pinch.

Hope that helps,
Brad

 

Thanks Brad, those are some good tips on the wires.
When I did it earlier, I did not move the wires back and forth, but there should be a lot inside the hole.

I might work on putting some more on tomorrow.

I have a Shop Vac here, and I may dig it out later also.