Log In
Search suggestions

    My Vehicles

    1987 Ford Tempo 2.3L TBI HP 4cyl

    My Store

    405 N COLLEGE ST
    (479) 443-4043

    OPEN 'til 9:00 PM today

    GET A $25 GIFT CARD FOR EVERY $100 SPENT ON ONLINE SHIP-TO-HOME ORDERS.

    Use Code: GIVETHANKS

    See Details

    BMW Cars 1999-06

    Hydraulic System

    Print

    Hydraulic System Bleeding



    The clutch and brake hydraulics use an approved DOT 4 brake fluid in their systems. The hydraulic system should be bled periodically, usually a minimum of every two years, or more often under severe use. Brake fluid can absorb moisture. Because condensation is heavier than brake fluid, and under normal conditions, will not mix with it, the sediment and condensation tend to collect in the slave cylinder and in the bottom of the master cylinder reservoir.

    If possible, before bleeding the system, use a siphon gun or a cooking baster to remove the old fluid, or remove the reservoir and flush it using a recommended brake cleaner or rubbing alcohol. If necessary, the reservoir can be flushed while removed from the vehicle using lightly pressurized water, however the reservoir must be flushed with brake cleaner or rubbing alcohol and dried completely before installation.

    There are a number of brake hydraulic bleeders available that use vacuum to "pull" the fluid through the hydraulic system. The advantage these tools offer is that the system can be bled without the help of an assistant.


    CAUTION
    Bleeding or flushing the clutch hydraulic system with dirty or contaminated fluid may result in component damage.

    When bleeding a clutch hydraulic system, always observe to following guidelines:



    Never reuse brake fluid
     
    Always bleed the system using fresh fluid
     
    Do not use fluid which has been left uncapped
     
    Use a recommended fluid which is compatible with the existing fluid
     

    1. Fill the reservoir with fresh fluid.
    2.  
    3. Fit a flare or box end wrench onto the slave cylinder bleeder screw.
    4.  
    5. Attach a (clear if available) rubber tube to the slave cylinder bleed screw and suspend it into a suitable clear drain container partially filled with brake fluid.
    6.  
    7. Open the bleeder screw and have an assistant press the clutch pedal to the floor.
    8.  
    9. While holding the clutch pedal to the floor, close the bleed screw.
    10.  
    11. Slowly release the clutch pedal to its fullest extension and recheck the reservoir fluid level. Top off as necessary.
    12.  
    13. Repeat the above steps until the fluid exiting the bleed screw is clean and free of all air bubbles.
    14.  
    15. Top off the clutch master cylinder reservoir as necessary.
    16.  



    Click image to see an enlarged view

    Fig. On E36 models, the hydraulic clutch system shares the reservoir that is mounted on the brake master cylinder



    Click image to see an enlarged view

    Fig. A vacuum tester and a bleeding attachment (shown bleeding the brakes here) eliminate the need for a helper. These units are available from automotive vendors

    The clutch system can be bled using a pressure bleeder. Follow the instructions that come with the pressure bleeder for the proper pressure bleeding procedure. The maximum line pressure while pressure bleeding must not exceed 36 pi (248 pa).

    1. Before servicing the vehicle, refer to the Precautions section.
    2.  
    3. To bleed a clutch manually requires the following:

      The assistance of a second person
       
      A section of hose that is compatible with brake fluid (preferably clear) and fits the slave cylinder bleeder valve snugly
       
      A container to catch the fluid that is bled through the system.
       

    4.  


    NOTE
    Cleanliness is of the utmost importance. Always be sure the fluid reservoir is as clean as possible to avoid bleeding debris or contaminated fluid into the system check valves and seals. As brake hydraulic fluid easily absorbs moisture, always use fresh fluid when bleeding a clutch hydraulic system. If the clutch hydraulic system has been run dry, or if the hydraulic fluid line, clutch slave or master cylinder has just been replaced, it may be necessary to repeat the bleeding procedure a number of times to remove all of the air. Make sure the reservoir does not run dry during bleeding. If the reservoir runs dry the bleeding process must be repeated until no air is present.

    1. To bleed the system perform the following:
      1. Top off the clutch hydraulic fluid reservoir using a fluid that meets the standards of the vehicle-s clutch hydraulic system.
      2.  
      3. With one end of a section of hose attached to the slave cylinder bleed valve and the other end of the hose submerged into a container of fresh brake hydraulic fluid, open the clutch slave cylinder bleed valve. Slowly press the clutch pedal to the floor and hold the pedal down.
      4.  
      5. Close the clutch slave cylinder bleed valve.
      6.  
      7. Slowly release the clutch pedal.
      8.  
      9. Check the hydraulic fluid level and top off as necessary.
      10.  

    2.  
    3. Repeat the above steps until the discharged fluid is clean and no air bubbles appear during the bleeding process.
    4.  

    The clutch system can be bled using a pressure bleeder. Follow the instructions that come with the pressure bleeder for the proper pressure bleeding procedure. The maximum line pressure while pressure bleeding must not exceed 36 pi (248 pa).

    1. Before servicing the vehicle, refer to the precautions in the beginning of this section.
    2.  
    3. To bleed a clutch manually requires the following:
      NOTE
      Cleanliness is of the utmost importance. Always be sure the fluid reservoir is as clean as possible to avoid bleeding debris or contaminated fluid into the system check valves and seals. As brake hydraulic fluid easily absorbs moisture, always use fresh fluid when bleeding a clutch hydraulic system. If the clutch hydraulic system has been run dry, or if the hydraulic fluid line, clutch slave or master cylinder has just been replaced, it may be necessary to repeat the bleeding procedure a number of times to remove all of the air. Make sure the reservoir does not run dry during bleeding. If the reservoir runs dry the bleeding process must be repeated until no air is present.



      The assistance of a second person
       
      A section of hose that is compatible with brake fluid (preferably clear) and fits the slave cylinder bleeder valve snugly
       
      A container to catch the fluid that is bled through the system.
       

    4.  
    5. To bleed the system perform the following:
      1. Top off the clutch hydraulic fluid reservoir using a fluid that meets the standards of the vehicle-s clutch hydraulic system.
      2.  
      3. With one end of a section of hose attached to the slave cylinder bleed valve and the other end of the hose submerged into a container of fresh brake hydraulic fluid, open the clutch slave cylinder bleed valve. Slowly press the clutch pedal to the floor and hold the pedal down.
      4.  
      5. Close the clutch slave cylinder bleed valve.
      6.  
      7. Slowly release the clutch pedal.
      8.  
      9. Check the hydraulic fluid level and top off as necessary.
      10.  

    6.  
    7. Repeat the above steps until the discharged fluid is clean and no air bubbles appear during the bleeding process.
    8.  

    1. Fill the reservoir.
    2.  
    3. Connect a bleeder hose from the bleeder screw to a container filled with brake fluid so air cannot be drawn in during bleeding procedures.
    4.  
    5. Pump the clutch pedal about 10 times and then hold it down.
    6.  
    7. Open the bleeder screw and watch the stream of escaping fluid. When no more bubbles escape, close the bleeder screw and tighten it.
    8.  
    9. Release the clutch pedal and repeat the above procedure until no more bubbles can be seen when the screw is opened.
    10.  
    11. If this procedure fails to produce a bubble-free stream:
      1. Pull the slave cylinder off the transmission without disconnecting the fluid line.
        NOTE
        Do not depress the clutch pedal while the slave cylinder is dismounted.

      2.  
      3. Depress the pushrod in the cylinder until it hits the internal stop. Then, reinstall the cylinder.
      4.  

    12.  

    The clutch system can be bled using a pressure bleeder. Follow the instructions that come with the pressure bleeder for the proper pressure bleeding procedure. The maximum line pressure while pressure bleeding must not exceed 36 pi (248 pa).

    1. Before servicing the vehicle, refer to the Precautions section.
    2.  
    3. To bleed a clutch manually requires the following:
      NOTE
      Cleanliness is of the utmost importance. Always be sure the fluid reservoir is as clean as possible to avoid bleeding debris or contaminated fluid into the system check valves and seals. As brake hydraulic fluid easily absorbs moisture, always use fresh fluid when bleeding a clutch hydraulic system. If the clutch hydraulic system has been run dry, or if the hydraulic fluid line, clutch slave or master cylinder has just been replaced, it may be necessary to repeat the bleeding procedure a number of times to remove all of the air. Make sure the reservoir does not run dry during bleeding. If the reservoir runs dry the bleeding process must be repeated until no air is present.



      The assistance of a second person
       
      A section of hose that is compatible with brake fluid (preferably clear) and fits the slave cylinder bleeder valve snugly
       
      A container to catch the fluid that is bled through the system.
       

    4.  
    5. To bleed the system perform the following:
      1. Top off the clutch hydraulic fluid reservoir using a fluid that meets the standards of the vehicle-s clutch hydraulic system.
      2.  
      3. With one end of a section of hose attached to the slave cylinder bleed valve and the other end of the hose submerged into a container of fresh brake hydraulic fluid, open the clutch slave cylinder bleed valve. Slowly press the clutch pedal to the floor and hold the pedal down.
      4.  
      5. Close the clutch slave cylinder bleed valve.
      6.  
      7. Slowly release the clutch pedal.
      8.  
      9. Check the hydraulic fluid level and top off as necessary.
      10.  

    6.  
    7. Repeat the above steps until the discharged fluid is clean and no air bubbles appear during the bleeding process.
    8.  

     
    AutoZone Logo