VALVE GP 8U6552 - Caterpillar

When using the 170-8500 Analyzer Gp, connect the "low pressure in" port to the S O S valve (16) on the base assembly. Use a fabricated suction tube (13) fitted with a Quick Connect Coupler (15) to connect the port to the S O S valve (16). The fabricated tube is required to collect an on-line sample when using the 170-8500 Analyzer Gp.
Illustration 15 g01333082
(16) S O S valve
(17) 169-8373 Fluid Sampling Bottle
If collecting a bottle sample, use the same S O S valve (16) and a Fluid Sampling Bottle (17).
Record an oil sample reading from the S O S valve on the filter cart before beginning the filter cycle.
After filtering the oil for 15 minutes, stop the procedure. Change the transmission filters. The new filters will help in the system cleaning. The new filters can remain in place until the next scheduled filter change. Changing the filters avoids opening the filter housing after the system has been cleaned. If the filter housing is opened, the housing becomes an inlet for contamination.
During the filtration process, the engine must be run at low idle for 5 minutes every 15 minutes. Running the engine will cycle the clean oil in the transmission sump into the transmission system and flush more contaminated oil back into the sump. With the engine at LOW idle and the parking brake ON, shift the transmission into and out of third gear forward. Shifting the transmission into and out of third gear forward will cycle the transmission oil.Note: This filtration process can be performed while running the engine.
The 170-8500 Analyzer Gp will indicate when the oil has reached an ISO level of 18/15. The final ISO level should be recorded before the machine is returned to the field.Note: Refer to "Oil Compartment Filtration Times", at the end of this document when a 170-8500 Analyzer Gp is not available.
When the target ISO level or the time interval has been met, close the air supply valve. Disconnect the air supply hose. Refer to Illustration 12.
Illustration 16 g01333084
(11) Discharge adapter assembly
(12) Filter cart discharge hose
Remove the discharge hose (12) and discharge adapter assembly (11) from the transmission filler tube. Install the dust cap on the nipple. Install the dust cap on the coupler. Store the discharge adapter (11) in a clean place for later use.
Install a clean transmission filler cap.
Illustration 17 g01333085
(9) Suction adapter assembly
(10) Filter cart suction hose
Disconnect the filter cart suction hose (10) from the suction adapter (9). Install the dust cap on the nipple. Install the dust cap on the coupler.
Place a drain pan under the transmission case. There will be some oil in the suction adapter assembly.
Illustration 18 g01333086
(9) Suction adapter assembly
(10) Filter cart suction hose
Remove the suction adapter (9) from the transmission case. Store the suction adapter (9) in a clean place.
Install a clean drain plug in the transmission case.
Check the transmission oil level before returning the wheel loader to service.
Disconnect the steering frame lock.Oil Compartment Filtration Times
If an on-line portable particle counter is not available to diagnose