2014/07/24 Caterpillar

Wheel Skidder:

525C (S/N: 5251-UP)

535C (S/N: 5351-UP)

545C (S/N: 5451-UP)

Description of Change: An improved Pressure Sensor is used on Wheel Skidders equipped with secondary steering.

Adaptable To: The improved Pressure Sensor offers improved dry packaging to protect assembled circuit boards.

Table 1

Required Parts
Item	Qty	Part Number	Description
1	1	221-3417	Pressure Sensor Gp

The improved Pressure Sensor Gp is adaptable to the following machines:

• 525C (S/N: 5251-1855)

• 535C (S/N: 5351-705)

• 545C (S/N: 5451-1188)

The improved Pressure Sensor Gp is effective in production in the following machines:

• 525C (S/N: 5251856-UP)

• 535C (S/N: 535706-UP)

• 545C (S/N: 5451189-UP)

Process Changes Implemented at the Supplier

1. Utilize dry packaging to protect assembled circuit boards from moisture.

2. Limit circuit board exposure time to atmospheric humidity during sensor assembly.

3. Modify the pattern for potting material application over the ASIC.

4. Revert to the adhesive used prior to the delamination issue.

5. Remove internal potting that sometimes contacts internal O-ring. Improved part identified with yellow dot sticker.