Vacuum Actuator - Updated Vacuum Hose Connection
TO: OUR MERCEDES-BENZ PASSENGER CAR DEALERSDATE: May 1991 (supercedes MBNA 07.1/17, April 1991)
REF.NO.: MBNA 07.1/17a
Subject:
Model 124, 128, M.Y. 1991
Modified Boost Control Valve Vacuum Actuator
Revision: This Service Information contains a revised vacuum actuator adjustment procedure.
As of August 1990 production, to prevent slippage of the vacuum hose from the vacuum actuator, the connection surface of the boost control valve vacuum actuator is coated differently. A disconnected hose can cause poor transmission shift quality.
Effective Serial Number
Model As of Chassis End Number
124.128 B 335751
On all vehicles manufactured prior to the above chassis end number, the vacuum hose to actuator connection must be modified, during the next shop visit, as described.
Since remnants of the prior surface coating can stick to the inside of the vacuum hose, approximately 100 mm of the vacuum hose must be replaced as per the following procedure.
NOTE:
VEHICLES ALREADY MODIFIED CAN BE IDENTIFIED BY THE PRESENCE OF A CONNECTION PIECE IN THE VACUUM HOSE LINE.
Procedure
1. Disconnect vacuum hose from vacuum actuator (100, Figure 1).
NOTE:
DO NOT REMOVE THE VACUUM ACTUATOR! If the actuator is removed. the boost control valve must be adjusted.
2. Plug fitting on actuator.
3. Remove coating from O.D. of fitting using emery paper, remove residue with compressed air.
4. Remove plug from actuator.
5. Cut vacuum hose at approximately 100 mm before vacuum connection (arrow. Figure 1).
6. Install new hose (approx. 100 mm) using connection piece. (arrow. Figure 1).
If vacuum actuator has been removed and reinstalled, perform the following procedure.
Procedure
1. Loosen two screws (c. Fig. 2).
2. Apply 385 +/- 5 mbar of vacuum to actuator. Adjust position of actuator via oblong slots (c) until lever (d) rests against stop (b). When lever is in this position, tighten screws (c). Release vacuum, then reapply vacuum to actuator. Readjust setting if necessary.
Parts Information
Part Name Part Number
Hose 617 997 08 82
Connector 603 078 00 47
In Case of Warranty
Operation: Vacuum actuator (hose), boost control valve, modify
Damage Code Operation Number Time Model(s)
14930 23 02.0865 0.2 hr 86