Measure and adjust pressure value - RA27037220350X(27-350)

Work NR. the work texts and work values and/or standard texts and setting-up times:

27-1135, 27-1160.

Fig 1: Measuring And Adjusting Pressure Value

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

Reference  

Lead for measuring of work pressure, modulate pressure and regulator pressure, pressure tubes through the window of the right driver door and clamp with the disk. Pressure tubes may not sag or may adjoin at the exhaust pipe.

In all adjust works at the vehicle with which the motor runs, the parking brake must be actuated and be the choice lever in position P.

In measurements while stationary, with inserted load position, actuate the parking brake in addition the service brake. After the test run let the motor and test fair places for density.

1. Measuring modulating pressure 
   NOTE: This test is only necessary in the following cases:

   1. When the modulating pressure unit has been replaced, removed or installed.
   2. After a transmission repair.
   3. In case of too smooth or too harsh shifting in all gears.

   Vacuum line	Detach from/mount on modulating pressure unit.
   Pressure gauge (measuring range up to 10 bar)	Connect/disconnect at test connection "M".
   Rubber cap	Detach from/plug into modulating pressure unit.
   Locking T-key	Pull out of locking slots, plug in and adjust modulating pressure by rotating key. (Each key turn by one detent produces a change in pressure of approx. 0.2 bar).

   Repair note 

   A modified modulating pressure unit has been installed phased in as of 08/92. Pressure gauge testing of the modulating pressure is generally no longer necessary.

   However, if adjustment of the modulating pressure by more than 0.2 bar is necessary during repair work, the modulating pressure can be set as previously by removing the cap (60b).

   Removing the cap destroys it, and it must be replaced when the work is completed. The new cap must be pressed on at the basic setting after the specified modulating pressure has been set. The pressure pin (59a) has also been modified with the introduction of the new modulating pressure unit.

   Fig 2: Identifying Modulating Pressure Unit

   Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

   At the specified modulating pressure, the cap is mounted at the "basic setting" (A) position.

   By rotating the cap (60b) from position "A" to "B", the modulating pressure can be reduced by 0.2 bar.

   This adjustment is made by rotating the cap up to the stop.

   Fig 3: Identifying Modulating Pressure

   Courtesy of MERCEDES-BENZ OF NORTH AMERICA.
2. Measuring governor pressure 

   Pressure gauge (measuring range up to 10 bar)	Connect/disconnect at test connection "MR".
   Road test at selector lever position "D"	Carry out on the roller dynamometer or on the road.
   	NOTE: For all vehicles the uniform formula applies: >0.5 bar at v > 30 km/h. If the indicated value deviates, or if no governor pressure is measured, remove, clean and install the centrifugal governor. Replace if necessary.

   Fig 4: Identifying Governor Pressure

   Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

   Special tool 

   Fig 5: Identifying Special Tool (123,589,04,21,00)

   Courtesy of MERCEDES-BENZ OF NORTH AMERICA.