Fresh Air Box Install

I've got a new fresh air box and drain hose from MTS. Is it possible to get the old out and new one in without dropping the heater plenum? I've taken the heater motor out, glove box out, and disconnected the ducts. It gives me more room, but the box doesn't seem to want to clear between the dash and plenum. Any suggestions? Thanks.

 

Remove the plenum.

 

I plan to do this tomorrow. Just looking, it's not clear to me how it comes out or where the screws are that are holding it in.

 

they are under the hood one behind the valve cover and a couple by the battery tray

 

Yep, the studs for the plenum come through the firewall, I think it's a 1/4" nut that holds them on. One above the battery tray toward the corner of the firewall, one underneath the battery tray, and one toward the center of the firewall, behind the valve cover if you have a straight six. I think there is only the three.

Keep in mind that if you're heating hoses are still hooked up you'll have to remove those too.

 

I see. I couldn't tell by the picture in the TSM if the heater core stays in when the plenum comes out or if they come out together.

 

yup it all comes as one unit

 

I'm glad I've tackled this...that plenum and heater core are nasty. I'm going to replace the core while I'm in there. What seal material is best?

I've already gotten new ducts and cables, so a cleaning and painting of the plenum will finish off my heat system refurbishment.

 

I found 4. 1 in the center of the firewall, 1 below the battery tray, and 2 above the battery tray.

 

I found some closed cell foam from Home Depot to use as a seal around the heater core. I think it was in the weather seal section.

 

I used some pink anti-static foam I had, used for packing electronic components. Likely you'll need to be creative.

 

log home gasket here... let your mind wander a little itll come to you

 

Another related thought, when I took mine out I didn't have anything in the firewall hole where the heater core tubes go through, I thought it might be a wear point when I put it back together so I put in some rubber grommets on the firewall holes. It was a tight fit but makes me feel comfortable to have a little extra protection.

 

mine had a foam rectangle with two holes in it behind the firewall around the heater pipes

 

Mine had the same stuff, and when I replaced my hoses, I replaced that foam with a piece of window-unit air conditioner foam.

Will the weather stripping foam at the hardware store work around the core in the plenum? I'm not sure if some stuff can't stand up to the heat.

 

i think it would its mostly a filler to keep the core from rattling