Gain extra benefits by becoming a Supporting Member Click here find out how!
Classic Performance Products Classic Parts
Ciadella InteriorsAmerican Auto Wire Classic Industries
Chevs of the 40sDanchuk Catalog
Hellwig Products IncPerformance Rod & CustomEcklers AutoMotive
Nu-Relics Power WindowsRain Gear Wiper Systems
Impala Bob's Bob's Chevy Trucks Bob's Chevelle Parts Bob's Classic Chevy

Username Post: Sticking AC Door        (Topic#351137)
Posts: 78

Reg: 10-27-16
05-16-18 06:18 PM - Post#2734135    

Been doing a few things to my 1990 C1500 HVAC system. Replaced the blend door actuator and blower motor. The last nagging issue is a sticking AC flapper door. This door and the defrost door are linkage driven by the mode door actuator. The actuator and spring loaded linkage works fine. The door itself gets stuck after sitting for long periods or when very hot outside. I am guessing there is a rubber edge gasket on the door that is maybe gummy. When it sticks you can watch the linkage move and after a few seconds the thing comes unstuck and bangs open. After sitting I can manually grab the linkage and put pressure on it to unstick it so I know it is the door and not the linkage or actuator. SO, has anyone got a fix for this? You can't really get to it to spray something in there. Thought about making a limit stop on the door shaft so it couldn't completely shut and get stuck but then I would always have some leakage past that door. What to do?

Posts: 27

Reg: 03-15-17
05-16-18 06:24 PM - Post#2734137    
    In response to go_hercules

What about replacing the foam with some that you put when a house window or door is leaking.

"7th Year" Silver Supporting Member
Posts: 3989
Loc: Salt Lake City
Reg: 06-20-09
05-16-18 08:41 PM - Post#2734148    
    In response to Gmctrucks

That’s not a bad idea. The trouble is, the door sits in such a position that the only way to get access to it is to unscrew the dash and rock it back toward the seat just to be able to see it.


'95 K1500 Z71 EC Short Step 5.7L+0.040/NV3500
'00 Explorer XLT 4.0 V6 Auto
'94 K2500 5.7 NV4500 ECLB - SOLD
‘87 GMC S15 SCLB 4.3 Auto - SOLD

"The only thing necessary for evil to triumph is for good men to do nothing" Sir Edmund Burke

Posts: 78

Reg: 10-27-16
05-16-18 09:07 PM - Post#2734149    
    In response to CowboyTrukr

Yeah, I don't think getting inside of it is even an option. What do you think of my thought of just putting a stop that will let it close just shy of completely shut?

Valued Contributor
Posts: 3992
Age: 35
Loc: wv
Reg: 08-29-12
05-17-18 06:03 AM - Post#2734158    
    In response to go_hercules

If it doesn't close all the way,the actuator will keep trying to close it until something breaks. It has a position sensor.


'88 Chevy K3500, aluminum head roller cam 511in³ stroker 10.5:1 compression, 96 NV 4500, 94-98 grille, 305/70-16 (33x12) BF Goodrich KM2s, 91 cluster swap

Posts: 78

Reg: 10-27-16
05-17-18 06:36 AM - Post#2734162    
    In response to bowtie44s

Actually on the 1990, it can't do damage because the actuator pushes through a spring loaded linkage. The linkage just loads up the spring as the actuator goes full travel. That is why I get the bang when the door finally lets loose. By the way, the reason the linkage pushes through the spring is not to protect or dampen things, it is so ONE actuator can cleverly control three doors simultaneously through linkages.

Icon Legend Permissions Topic Options
Report Post

Quote Post

Quick Reply

Print Topic

Email Topic

FusionBB™ Version 2.1
©2003-2006 InteractivePHP, Inc.
Execution time: 0.117 seconds.   Total Queries: 16   Zlib Compression is on.
All times are (GMT -0800) Pacific. Current time is 02:04 PM