APPENDIX B -- CHECKING CLUTCH AND RETARDER PRESSURES

W T E CWI IECEII E LECTO NNCC CONTROLS S RT R OLESL E S HINO T I ANUALA N U A L

T I I L EC T R RO I I C O N T R O L T OUB U B HOOT O G MN G M

APPENDIX B -- CHECKING CLUTCH AND RETARDER PRESSURES

Checking individual clutch pressures helps to determine if a transmission malfunction is due to a mechanical or an

electrical problem. Properly making these pressure checks requires transmission and vehicle (or test stand)

preparation, recording of data, and comparing recorded data against specifications provided. These instructions are

for all WT Series transmissions.

NOTE:

Check to see if there are diagnostic codes set which are related to the transmission difficulty you are

evaluating. Proceed to make mechanical preparations for checking clutch pressures after codes have

first been evaluated.

Transmission and Vehicle Preparation

1. Remove the plugs from the pressure tap locations where measurement is desired (refer to

MD/B 300/B 400

MD 3070PT TRANSFER CASE

HD/B 500

C6 (MD 3070PT ONLY)

MAIN

T-CASE

C6 PRESSURE TAP

CONNECTOR

(On left side of

adapter housing,

HD 4070

near the bottom)

FRONT VIEW

NOTE: Retarder charging pressure tap is located on the

retarder control valve body for all models with retarder.

V05929

Figure B1. Clutch Pressure Check Points

Be sure that the hydraulic fittings have the same thread as the plugs removed

CAUTION:

(7/16-20 UNF-2A). Also please note that these fittings must be straight thread,

O-ring style. Failure to do this will result in damage to the control module.

2. Install hydraulic fittings suitable for attaching pressure gauges or transducers.

3. Connect pressure gauges or transducers. Pressure gauge set J 26417-A is available for this

purpose. See Table B2 for pressure levels expected.

4. Check that engine speed can be monitored (Pro-Link 9000 diagnostic tool may be used for this

purpose).