Volvo RWD 900 Forum

INDEX FOR 10/2025(CURRENT) INDEX FOR 1/2005 900 INDEX

[<<]  [>>]


THREADED THREADED EXPANDED FLAT PRINT ALL
MESSAGES IN THIS THREAD




  REPLY TO THIS MESSAGE    PRINT   SAVE 

Tracking Down Vacuum Leak Causing the 'No-air-when-accelerating' problem. 900 2004

posted by  Philip on  Thu Jul 19 04:29 CST 2007
Author: [PROFILE] [EVERY POST] [THREADS] [BEST POSTS] RSS Feed     [IGNORE ALL POSTS]
last visit: Thu Oct 23 10:21 CST 2014
[RELATED]

Here is what I have done (1994 940 Turbo wagon):

Checked the check-valve under the hood -- blowing into it, no air goes through from one side and air (somewhat restricted) does goes through from the other side.

Bought a mighty vac and checked the vacuum motors --- the usual culprit one holds a vacuum; the next closest one holds a vacuum in one line, but the blue line does not.

Checked the lines that leave the motors --- these do not hold a vacuum.

I do not see any vacuum tank -- do 940's have a tank?

The lines look like they go from the motors to the MCC. Do I next need to pull the MCC and check the lines and the pipes they plug into? Should the pipes into the MCC hold a vacuum?

Thanks,








  •   REPLY TO THIS MESSAGE    PRINT   SAVE 

    Tracking Down Vacuum Leak Causing the 'No-air-when-accelerating' problem. 900 2004

    posted by  poolman on  Thu Jul 19 10:02 CST 2007
    Author: [PROFILE] [EVERY POST] [THREADS] [BEST POSTS] RSS Feed     [IGNORE ALL POSTS]
    last visit: Sun Dec 26 02:03 CST 2010
    [RELATED]

    Under the panel on the drivers side-there are two vacuum motors-one of them will have two lines going to it. If one of those lines going into the vac motor does not hold vac you have found the motor which has gone south. I put a plug on the lead there and another on the vac line going back to the engine. That took care of the problem-if you replace the motor you will ahve a bunch of time in labor and the cost of the vac motor.
    Hope that helps
    Poolman








    •   REPLY TO THIS MESSAGE    PRINT   SAVE 

      Tracking Down Vacuum Leak Causing the 'No-air-when-accelerating' problem. 900 2004

      posted by  Philip on  Fri Jul 20 02:22 CST 2007
      Author: [PROFILE] [EVERY POST] [THREADS] [BEST POSTS] RSS Feed     [IGNORE ALL POSTS]
      last visit: Thu Oct 23 10:21 CST 2014
      [RELATED]

      Poolman,

      Thanks for saving me some time and effort by not taking out the MCC to track down the lines there. For some reason, I thought that only one line into a motor had to hold a vacuum. Sure enough, I plugged the two lines into the motor where one side was not holding a vacuum and the problem is fixed.

      Did you plug the connection that came out of the motor and that line only --- and leave the "good" side connected? Did I lose some function by disconnecting and plugging both lines?








      •   REPLY TO THIS MESSAGE    PRINT   SAVE 

        Tracking Down Vacuum Leak Causing the 'No-air-when-accelerating' problem. 900 2004

        posted by  poolman on  Fri Jul 20 05:02 CST 2007
        Author: [PROFILE] [EVERY POST] [THREADS] [BEST POSTS] RSS Feed     [IGNORE ALL POSTS]
        last visit: Sun Dec 26 02:03 CST 2010
        [RELATED]

        Yes plugg the side from the engine and the side thats bad on the vac motor-leave the side thats good hooked up.
        You will lose some function-I belive I lost the floor vent-may be diff with you
        but loosing the floor was no big thing with me.
        Poolman







<< < > >>



©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.