Autry Posted April 8, 2023 Share Posted April 8, 2023 My 1991 Buick Riviera HVAC flap is broken the air only comes out from the defroster any fixes please help 9043700911 or email chubby91565@gmail.com Link to comment Share on other sites More sharing options...
Paul Dobbin Posted April 8, 2023 Share Posted April 8, 2023 (edited) If you can't get a new part, the You-Pull-It junk yards are lot of fun too. Edited April 8, 2023 by Paul Dobbin (see edit history) Link to comment Share on other sites More sharing options...
dship Posted April 8, 2023 Share Posted April 8, 2023 1990-1993 Riviera and 1990-1991 Reatta use the same HVAC unit. They can be found on eBay often, or as Paul above mentioned there might be one at a local (to you) pick n' pull auto salvage yard. Hopefully you have a Factory Service Manual for your era Buick. The manual shows how to remove and install a HVAC unit. 2 Link to comment Share on other sites More sharing options...
Barney Eaton Posted April 8, 2023 Share Posted April 8, 2023 Are you sure the flap is broken? If you loose vacuum that allows the controller to change the output, the default position is the defroster. I would check and verify that your vacuum hoses are good and not unplugged or cracked. The main hose comes from the top of the engine back to the firewall and there is a plastic T that is also a check valve. I have seen these "T" break and you loose vacuum to the controller. Another check is does your cruise control work..... if the vacuum system is leaking the cruise will not hold. 2 Link to comment Share on other sites More sharing options...
Marty Roth Posted April 8, 2023 Share Posted April 8, 2023 14 minutes ago, Barney Eaton said: Are you sure the flap is broken? If you loose vacuum that allows the controller to change the output, the default position is the defroster. I would check and verify that your vacuum hoses are good and not unplugged or cracked. The main hose comes from the top of the engine back to the firewall and there is a plastic T that is also a check valve. I have seen these "T" break and you loose vacuum to the controller. Another check is does your cruise control work..... if the vacuum system is leaking the cruise will not hold. I was about to add the same note as Barney - It happened in two of our cars Link to comment Share on other sites More sharing options...
Ben Bruce aka First Born Posted April 8, 2023 Share Posted April 8, 2023 21 minutes ago, Marty Roth said: I was about to add the same note as Barney - It happened in two of our cars Yep. My 1992 Roadmaster same thing. I had to change the vacuum " switch" in the control panel. Real high tech! Not. Ben Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now