Volvo RWD 900 Forum

INDEX FOR 10/2025(CURRENT) INDEX FOR 4/2018 900 INDEX

[<<]  [>>]


THREADED THREADED EXPANDED FLAT PRINT ALL
MESSAGES IN THIS THREAD




  REPLY TO THIS MESSAGE    PRINT   SAVE 

Mushy brake pedal 900

posted by  Lucas Cole on  Fri Jul 25 10:57 CST 2008
Author: [PROFILE] [EVERY POST] [THREADS] [BEST POSTS] RSS Feed     [IGNORE ALL POSTS]
last visit: Fri Sep 5 02:51 CST 2008
[RELATED]

Recently purchased a 92 940 Turbo with 146K. (I ought to know better . . . adding it to my 88 740 GLE and 95 940 Turbo Wagon.) The car runs fine but the brakes are an issue. The car stops but brakes go right to the floor. Mechanic has replaced the master cylinder (didn't fix the problem) and just went over the car again. There's no fluid leak at all but some kind of air leak in the system (from the rear) but they can't find it. Has a Bendix brake booster. They could try replacing the brake calipers for another $400 but won't guarantee that will fix the problem. Unfortunately, I'm not much of a mechanic and mine is scratching his head. I've already dumped a lot of money into this car but am ready to give up. Any ideas for what to look for? Thank you!







  •   REPLY TO THIS MESSAGE    PRINT   SAVE 

    Mushy brake pedal 900

    posted by  trichard on  Fri Jul 25 12:07 CST 2008
    Author: [PROFILE] [EVERY POST] [THREADS] [BEST POSTS] RSS Feed     [IGNORE ALL POSTS]
    last visit: Fri Oct 24 05:52 CST 2014
    [RELATED]

    a brake system must remain a closed system in order to function. therefore since yours is not working it is no longer a closed system.

    this means 1 of only 4 possibilities:

    1.the master cylinder is bad. you said it was new so i ask you to ask your mechanic, "did you bench bleed the mc before you installed it? meaning if you did not there was large amounts of air in an un bled mc so that is now in the system? if you did not bench bleed it. mc's have been known to be bad out of the box. does he know for fact this is not bad?

    2. you have a leak of fluid somewhere. you said the system shows no leaks so we can ignore this one.

    3. you have air somewhere in the system which has not been bled. has he pressure bled the entire system? i would suggest doing this: buy some blue or orange dot 4 brake fluid from fcp groton and have your mechanic pressure bleed the system using the blue.in this way he will know with 100% certainty each caliper is pressure bled right when only blue fluid emerges.

    4. you have caliper that was assembled incorrectly and so can not be bled correctly . it is rare but it happens. they come in halves and if not they are assembled right the bleed channels do not line up so air can not be removed. are you sure all the calipers are assembled right?








    •   REPLY TO THIS MESSAGE    PRINT   SAVE 

      Mushy brake pedal 900

      posted by  Lucas Cole on  Fri Jul 25 14:35 CST 2008
      Author: [PROFILE] [EVERY POST] [THREADS] [BEST POSTS] RSS Feed     [IGNORE ALL POSTS]
      last visit: Fri Sep 5 02:51 CST 2008
      [RELATED]

      Not sure about the calipers. I do know the mechanic went over things pretty thoroughly trying to figure things out. Meanwhile, these are great tips -- I will pass them on. Thank you.







<< < > >>



©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.