2009/08/31 Hydraulic Oil Lines Groups for the Power Train Have Been Updated on Certain Wheel Tractor-Scrapers {3016, 3177} Caterpillar

Wheel Tractor-Scraper:

627G (S/N: CEZ1-UP; DBZ1-UP)

637G (S/N: CEJ1-UP; CEM1-UP; DEX1-UP; DEY1-UP)

Description of Change: Improved routing for the hydraulic lines group on the power train, and updated groups for transmission tanks are now available on certain Wheel Tractor-Scrapers. Reworking the line for the air breather routes any spillage of hydraulic oil from the hydraulic tank into the transmission case. Air is then vented from the connection on top of the case for the transmission back up to the breather by way of the second hydraulic line. This prevents oil from leaking through the air breather for the power train.

Adaptable To:

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NOTICE
Care must be taken to ensure that fluids are contained during performance of inspection, maintenance, testing, adjusting and repair of the product. Be prepared to collect the fluid with suitable containers before opening any compartment or disassembling any component containing fluids. Refer to Special Publication, NENG2500, "AVSpare Dealer Service Tool Catalog" for tools and supplies suitable to collect and contain fluids on AVSpare products. Dispose of all fluids according to local regulations and mandates.

Table 1

The improved Power Train Breather is Effective on the Following Machines.
Sales Model	Serial Number
627G	S/N:DBZ918-UP
637G	S/N:DEX391-UP
637G	S/N:DEY227-UP
(1)627G	S/N:DBD916-UP
(1)637G	S/N:DFJ409-UP

( 1 )

The serial numbers for the wheel tractors correlate with the wheel scrapers that are listed above. The serial numbers for the wheel tractors are provided for reference only.

Table 2

The New Parts are Adaptable Back to the Beginning of Production for the Power Train Breather on the Following Machines.
Sales Model	Serial Number
627G	S/N:DBZ1-UP
637G	S/N:DEX1-UP
637G	S/N:DEY1-UP
(1)627G	S/N:DBD1-UP
(1)637G	S/N:DFJ1-UP

( 1 )

The serial numbers for the wheel tractors correlate with the wheel scrapers that are listed above. The serial numbers for the wheel tractors are provided for reference only.

The 263-2931 Power Train Oil Lines Gp has been updated on the 627G Wheel Tractor-Scrapers, and the 195-2400 Power Train Oil Lines Gp has been updated on the 637G Wheel Tractor-Scrapers. The new 342-7876 Hydraulic Tank As replaces the former 197-7618 Hydraulic Tank As on these machines.

The power train breather for the 627G and the 637G Wheel Tractor-Scraper can be updated by using various fittings, assorted parts, and a fabricated threaded rod. The instructions below provide a procedure to perform the rework. The hydraulic tank will not require removal, opening, or welding in order to perform this rework. The tank will not require internal cleaning after this rework.

Table 3

Required Part for the Update of the Oil Breather
Item	Qty	Part number	Description
1	1	1L-8444	Tee
2	1	Fabricated	Threaded Rod
3	1	1N-8559	Service Tee
4	1	343-0778	Hose As
5	1	343-0777	Hose As
6	1	7D-0702	Connector
7	1	5B-8978	Tee
8	1	7D-0477	Elbow
9	1	5P-3413	Pipe Sealant

Fabricate the Threaded Rod

Illustration 1	g01962233
The threaded rod is manufactured from SAE C-1018 or ASTM-A36 material. (A) Cut the rod to 38.10000 mm (1.5 inch) long. (B) The size of the bar stock is 26.67000 mm (1.05 inch) in diameter.

1. Cut the bar to a maximum length of 38.10000 mm (1.5 inches). A shorter rod will allow more clearance above the breather when the unit is assembled.

2. Thread one end of the solid round bar by using a .75 - 14 NPTF tap.

3. Apply 5P-3413 Pipe Sealant to the threads on the rod. Then insert the threaded end of the rod into the 1L-8444 Tee that will be used in the assembly. This will provide a fixture in order to cut the .75 - 14 NPTF threads on the other end of the rod.

Remove the Existing Breather

Illustration 2	g01962575
View of existing Tee on the hydraulic tank and the hose that connects hydraulic tank to the Transmission

1. The top cover to the power pack may need to be removed for access. Remove the four bolts that secure the cover and remove the cover.

2. Remove the existing transmission breather. Next remove the pipe tee's from the top of the oil tank. Then remove the hose that connects to the tee to the transmission case.

Install the New Breather

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Illustration 3	g01962290

1. Install the parts in this procedure on the 637G, and the 627G Wheel Tractor-Scraper. Apply 5P-3413 Pipe Sealant (9) to all threaded joints.

   Note: It may be necessary to switch the two new hoses at the lower connections in order to provide a better routing. Orient the fittings in order to prevent interferences, and the hoses from rubbing.

2. Reinstall the top cover if the top cover was removed.