Video - C10 Cowl Cleaning + Old Air Products Cowl Grills

[bry593]

The video below shows how I cleaned out my '71 C20 cowl. There was quite a bit of debris packed right up to the floor vent. It's important to clean this out once in awhile to keep rust from forming. GM failed to put a grill or screen on the outside cowl panel and any leaves, seeds or dirt will end up at the low spot of the cowl air intake.

To prevent recurrence, I installed some Old Air Products cowl grills (p/n 50-7236B). These are decent for the money and I'd recommend using them.

Here's the video:
https://www.youtube.com/watch?v=SFr7TsNVrvc

[RichardJ]

So, did you finish the job?

The rubber on the vent doors need replacing. drill out the tiny rivets on the door(s) and replace the rubber with new rubber material that is about 1/2' wider on all sides, except a little shorter top/bottom.
Hardware stores sell the rubber material in sheets. If you can find some reinforced rubber sheets that is flexible enough, it will last longer.

[jimijam00]

Originally Posted by RichardJ

drill out the tiny rivets on the door(s) and replace the rubber with new rubber material

or just buy repops and spend the extra time doing something else.

[Peanut74]

I feel your pain. My air ducts were full to the bottom of the doors. The passenger duct had rotted out bottom so I had to make a new one. Not had just a bit of a PITA to get the radius right.

I got some black gutter screen from a local home improvement store so I can make my own cowl screen.

[franken]

https://www.oldairproducts.com/produ...-cowl-vent-kit

[bry593]

Just realized I forgot to mention, there are HVAC doors at both sides folks. The passenger side is very similar to the driver's. You need to clean both out.

No, didn't bother riveting or stapling any new rubber to the fresh air vents. Not worried about it. Pick your battles as they say.

[firedemon]

i used the lmc screens seems the holes are too small . theres a huge loss in air flow with them in . i like having them open when its hot out

[Andy4639]

I use screen porch screen it's cheap. I also bought new doors for the kick panels.

[Orange Crate]

Originally Posted by firedemon

i used the lmc screens seems the holes are too small . theres a huge loss in air flow with them in . i like having them open when its hot out

Sorry to drag this ol' thing to the top but I couldn't find a newer thread to respond to.

I just received my LMC screens and I have to second the opinion here that the holes are too small. I haven't done business with LMC in a LONG time because they have crap products. I did a search about three weeks ago looking for cowl screen pics and a few here had mentioned the LMC product. I kinda crossed my fingers and held my nose and hit the "check out" button. OK, so NOW I am really done with them, no faking it anymore. No updates on the shipment, waited a week to get them, product is as stated above and then they had two of the same side in the box, and I can't put my cowl on this weekend. Nice! So there you go....hopefully it was worth knocking the dust off of this one.

[54blackhornet]

I picked up a screen door that someone trashed. Cut out two pieces of the screen and put it underneath the cowl. Works great.

[Orange Crate]

I can see that there are other vendors that supply better material for their cowl screens. I looked at one that has a octagon shape to the holes so I'll order that one. The octagon holes allow closer spacing so a much better airflow (this is actually what I thought I was getting, but you can't zoom in on the LMC picture to see that clearly). The LMC product acts more like a block off plate more than anything else. The first pic is from OregonNed and I like the way it looks, better airflow but still provides the filtering I want. Both sides of my original cowl plenum were completely rotted away forcing be to source a rust free cab (that was easy!)

[54blackhornet]

Orangecrate that is one fine looking cab !

[LS short box]

When I brought my 68 home it came out the CA high desert. The cowl and vents were packed to the top with pine needles and mouse and rat nests.
I pulled the vent doors out and cleaned every thing out. The seals on the vent doors were all but gone.
So because I'm cheap I went down to the local tire shop and they gave me an bad truck inner tube. I made the new door seals out of the inner tube. Cost me nothing.

[JMac11]

One thing I did while I had the front clip off was take a hole saw and enlarges the cowl drain enough that acorns wouldn't clog the system, plus I put in a cowl screen too.

[bry593]

With the cowl screens, I don't believe anything will ever block the drain again. Well, maybe if you park under a pine tree or something like that. Funny the way people think they are protecting their vehicle by parking under a tree. You'd be much better off parking out in the rain and sun.

[scottdburnett]

Any advice on how to clean up this mess?

Prior owner had glued a vinyl covered piece of cardboard over the kick panel and vent. I assume to cover up the metal that had been eroded by rust and debris. Not up for a full teardown and metal repair at this time.
I'm thinking about just getting the abs kick panels and reproduction vents from LMC and doing my best to get them to fit and stay in place.

[PbFut]

Good input. My cowl is still off. Keep going back and forth on adding a screen. I live in so cal so tree leaves are less than other parts of the country. Air flow is way more important. Your feedback provided the final decision to pass on the screen. Thank you.