Side air vents. Should each side blow equally?

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

MisterB

Full Access Member
Joined
Sep 9, 2019
Posts
676
Reaction score
845
Location
Northwest
First Name
AJ
Truck Year
1980
Truck Model
GMC K2500 4X4
Engine Size
350
I'm referring to those floor side vents that just let in fresh air when you're driving at speed.

On my truck, the passenger side blows quite a bit more than the drivers side. Is that normal, or is something maybe plugged in there? Besides directly behind the flap that opens (which I have already checked), where else can I check?

Sent from my SM-N975U1 using Tapatalk
 

80BrownK10

Full Access Member
Joined
Oct 22, 2019
Posts
1,878
Reaction score
1,247
Location
Greenwood, SC
First Name
Nate
Truck Year
1980
Truck Model
K10
Engine Size
350
I'm referring to those floor side vents that just let in fresh air when you're driving at speed.

On my truck, the passenger side blows quite a bit more than the drivers side. Is that normal, or is something maybe plugged in there? Besides directly behind the flap that opens (which I have already checked), where else can I check?

Sent from my SM-N975U1 using Tapatalk
Don't know. I wish I had them. I have an AC cab. And I haven't fixed the AC yet. 100+ heat index is just hot driving .
 

Frankenchevy

Proverbs 16:18
Joined
Jan 3, 2018
Posts
6,082
Reaction score
7,756
Location
USA
First Name
Jeremy
Truck Year
Square
Truck Model
CUCV
Engine Size
Small
Try running a hose down the driver’s side of the cowl with the vent closed. Might let you know if you have leaf debris accumulated down there.
 

MisterB

Full Access Member
Joined
Sep 9, 2019
Posts
676
Reaction score
845
Location
Northwest
First Name
AJ
Truck Year
1980
Truck Model
GMC K2500 4X4
Engine Size
350
Try running a hose down the driver’s side of the cowl with the vent closed. Might let you know if you have leaf debris accumulated down there.
Do you know where the inlet is for the vent, and then how or routes? I can't seem to find a schematic anywhere

Sent from my SM-N975U1 using Tapatalk
 

86454k30

Full Access Member
Joined
Oct 16, 2017
Posts
93
Reaction score
140
Location
PNW
First Name
Larry
Truck Year
1981
Truck Model
CHEVROLET
Engine Size
350
The openings in the top of the cowl in front of the windshield is where the air arrives from. See the plastic vented covers? Thats where the air enters the cowl for your vents.

You must be registered for see images attach
 

MisterB

Full Access Member
Joined
Sep 9, 2019
Posts
676
Reaction score
845
Location
Northwest
First Name
AJ
Truck Year
1980
Truck Model
GMC K2500 4X4
Engine Size
350
The openings in the top of the cowl in front of the windshield is where the air arrives from. See the plastic vented covers? Thats where the air enters the cowl for your vents.

You must be registered for see images attach
Cool. I recently replaced the screen and the rubber seal, and while I had it apart, I made sure it was clean down in there. Once it goes down the cowl, where does it go from there, before it ends up at the side floor vents?
You must be registered for see images attach


Sent from my SM-N975U1 using Tapatalk
 

AuroraGirl

Full Access Member
Joined
Sep 8, 2019
Posts
9,693
Reaction score
6,869
Location
Northern Wisconsin
First Name
Taylor
Truck Year
1978, 1980
Truck Model
K10, K25
Engine Size
400(?), 350
I didnt realize the AC cabs DIDNT have those vents, or was it just misunderstanding? My non AC cab has a driver/passenger, and my 78 i guess i never checked
 

legopnuematic

Licensed Junk Dealer
Supporting Member
Joined
Oct 27, 2016
Posts
2,506
Reaction score
6,482
Location
MO
First Name
Spencer
Truck Year
1971, 1̶9̶7̶4, 1976, 1979,1̶9̶8̶5, 2002
Truck Model
Dart Swinger, Sierra 10, C10 Cheyenne, C10 Big Ten, Silverado 10, Ram 2500
Engine Size
225/6, 350 c.i., 350 c.i., 5.9l Cummins
I didnt realize the AC cabs DIDNT have those vents, or was it just misunderstanding? My non AC cab has a driver/passenger, and my 78 i guess i never checked
All cabs have provisions for fresh air inlets, and kick panel vents, non a/c squares used the pull type vents, the a/c trucks use them in conjunction with vacuum pods to open or close depending on what setting it's on, a/c trucks also have a flapper under the cowl for recirculating in max a/c or defrost. So besides the firewall differences, any cab can be set up for a/c or no a/c.

Sent from my Moto Z (2) using Tapatalk
 

Doppleganger

Full Access Member
Joined
May 24, 2019
Posts
12,705
Reaction score
58,940
Location
OH-MI: Just like it sounds
First Name
Chris
Truck Year
1985
Truck Model
K20
Engine Size
5.7
Cool. I recently replaced the screen and the rubber seal, and while I had it apart, I made sure it was clean down in there. Once it goes down the cowl, where does it go from there, before it ends up at the side floor vents?

Sent from my SM-N975U1 using Tapatalk

The rubber seal - one where the hood meets the cowl? Where did you get the new screen? I'm fixing to tear mine all apart and am collecting parts. Be my luck I'd have it all dissected and the part would be NLA or back ordered.

THX
 

MisterB

Full Access Member
Joined
Sep 9, 2019
Posts
676
Reaction score
845
Location
Northwest
First Name
AJ
Truck Year
1980
Truck Model
GMC K2500 4X4
Engine Size
350
The rubber seal - one where the hood meets the cowl? Where did you get the new screen? I'm fixing to tear mine all apart and am collecting parts. Be my luck I'd have it all dissected and the part would be NLA or back ordered.

THX
I got the cowl screen and the hood to cowl rubber seal from LMC

Sent from my SM-N975U1 using Tapatalk
 

Craig 85

Full Access Member
Joined
Jan 25, 2017
Posts
3,917
Reaction score
4,116
Location
Nashville, TN
First Name
Craig
Truck Year
1985
Truck Model
K30 SRW
Engine Size
454/TH-400/NP205
Here the best way to describe the flow. Fresh air goes in at the yellow arrow. It flows down the side of the cowl and out at the fan motor (round hole). From there, it follows the red arrow through the A/C or heater box and back into the cab at the rectangular hole.

If you have A/C and put it on max, there is a flap under the cowl left of the yellow arrow that mostly closes and the door in the passenger kick panel opens (photo #2) to recirculate air from inside the cab.

EDIT: I realized you probably meant the kick panel vents. I would guess the driver's side may have some debris in the cowl. I had a '64 Chevelle back in the day with no A/C and kick panel vents. Both vents flowed the same.

You must be registered for see images attach

You must be registered for see images attach
 

MisterB

Full Access Member
Joined
Sep 9, 2019
Posts
676
Reaction score
845
Location
Northwest
First Name
AJ
Truck Year
1980
Truck Model
GMC K2500 4X4
Engine Size
350
Here the best way to describe the flow. Fresh air goes in at the yellow arrow. It flows down the side of the cowl and out at the fan motor (round hole). From there, it follows the red arrow through the A/C or heater box and back into the cab at the rectangular hole.

If you have A/C and put it on max, there is a flap under the cowl left of the yellow arrow that mostly closes and the door in the passenger kick panel opens (photo #2) to recirculate air from inside the cab.

EDIT: I realized you probably meant the kick panel vents. I would guess the driver's side may have some debris in the cowl. I had a '64 Chevelle back in the day with no A/C and kick panel vents. Both vents flowed the same.

You must be registered for see images attach

You must be registered for see images attach
Correct. Kick panel vents. I can't find any explanation anywhere that shows how the air flows and ends up at the vents on the kick panel

Sent from my SM-N975U1 using Tapatalk
 

Craig 85

Full Access Member
Joined
Jan 25, 2017
Posts
3,917
Reaction score
4,116
Location
Nashville, TN
First Name
Craig
Truck Year
1985
Truck Model
K30 SRW
Engine Size
454/TH-400/NP205
Here's another picture. Air flows from the top of the cowl down the sides and to the red stars. Pretty simple. The vertical part of the cowl is double walled. If you take off the kick panel the vent door are attached to them. You would be able to reach your hand to where the red stars are.

One of the easiest way to see if you have debris in that area, is take a garden hose with high pressure nozzle and spray into the bottom of your fender just ahead of the door. I did this on my last truck, you wouldn't believe how many dead leaves and other crap came out. I actually added a hole to the bottom of the fender so I could clean the area easier and drain water/mud.

You must be registered for see images attach
 

MisterB

Full Access Member
Joined
Sep 9, 2019
Posts
676
Reaction score
845
Location
Northwest
First Name
AJ
Truck Year
1980
Truck Model
GMC K2500 4X4
Engine Size
350
Here's another picture. Air flows from the top of the cowl down the sides and to the red stars. Pretty simple. The vertical part of the cowl is double walled. If you take off the kick panel the vent door are attached to them. You would be able to reach your hand to where the red stars are.

One of the easiest way to see if you have debris in that area, is take a garden hose with high pressure nozzle and spray into the bottom of your fender just ahead of the door. I did this on my last truck, you wouldn't believe how many dead leaves and other crap came out. I actually added a hole to the bottom of the fender so I could clean the area easier and drain water/mud.

You must be registered for see images attach
Awesome info. Thanks!

Sent from my SM-N975U1 using Tapatalk
 

Rusty Nail

Full Access Member
Joined
Jan 29, 2015
Posts
10,041
Reaction score
10,133
Location
the other side of the internet
First Name
Rusty
Truck Year
1977
Truck Model
C20
Engine Size
350sbc
I bought a pair of these from Johnny Craigslist only to be let down that they couldn't work in my truck (AC cab)
 

Latest posts

Forum statistics

Threads
44,163
Posts
950,656
Members
36,276
Latest member
2manysquares2care
Top