The message to which you are about to reply is shown first. GO TO REPLY FORM



 VIEW    REPLY TO THIS MESSAGE Replies to this message will be emailed.    PRINT   SAVE 

heater core? S90-V90

It usually doesn't take much vacuum to actuate the diaphragm and close the heater valve. These cars have a well know history of vacuum leaks both in the engine compartment and the HVAC system, so it is unlikely that your heater control valve is bad. But that can easily be checked by connecting an engine vacuum line with plenty of vacuum to the valve temporarily and see it it actuates. If you have a leak in the HVAC system which it probably is, we can give you some hints where to look.

What ambient temperatures are you running the A/C in? The reason I ask is because it was -8F here last night. A/C cycling is a function of temperature and state of charge. Adding R134a is relatively simple nowadays and cheap. You can buy a can of R134a and a gauge for ~$20 USD at most all Wal-marts.

DEWFPO

--
1998 S90 077,400 and 1995 964 154,100






USERNAME
Use "claim to be" below if you don't want to log in.
PASSWORD
I don't have an account. Sign me up.
CLAIM TO BE
Use only if you don't want to login (post anonymously).
ENTER CAPTCHA CODE
This is required for posting anonymously.
OPTIONS notify by email
Available only to user accounts.
SUBJECT
MODEL/YEAR
MESSAGE

DICTIONARY
LABEL(S) +
IMAGE URL *
[IMAGE LIBRARY (UPLOAD/SELECT)]

* = Field is optional.

+ = Enter space delimited labels for this post. An example entry: 240 muffler


©Jarrod Stenberg 1997-2022. All material except where indicated.


All participants agree to these terms.

Brickboard.com is not affiliated with nor sponsored by AB Volvo, Volvo Car Corporation, Volvo Cars of North America, Inc. or Ford Motor Company. Brickboard.com is a Volvo owner/enthusiast site, similar to a club, and does not intend to pose as an official Volvo site. The official Volvo site can be found here.