637 TRACTOR-SCRAPER Every 500 Service Hours Or 3 Months Caterpillar

(39)Hydraulic Control System - Change Filter Element

1. Lower bowl and apron. Move ejector forward and stop engine. Move scraper controls to relieve pressure. Wait 5 minutes before servicing hydraulic system.

2. Open bleed valve to release pressure.

3. Remove filter cover, elements, and screen. Wash screen in kerosene.

4. Install new seal.

5. Install new elements and install screen.

6. Install cover, and tighten to 43 ± 4 lb. ft. (5,9 ± 0.6 mkg).

7. Open bleed valve.

8. Start engine. Close bleed valve when oil flows without air bubbles.

9. Check oil level. Add oil if necessary.

(40)Cushion-Hitch System - Change Filter Element

1. Remove cover and used element. Clean cover and housing and install new seal.

2. Install new element and cover. Start engine.

3. Open bleed plug. Close plug when oil flows without air bubbles. Check hydraulic control system oil level.

(41)Cushion-Hitch Accumulator

Your AVSpare dealer is equipped to service accumulator nitrogen precharge pressure.

(42)Tractor Transmission System - Clean Magnetic Strainer

1. Remove cover.

2. Remove screen and magnets and wash in clean kerosene.

3. Install screen and magnets as a unit with small end of tube out. Be sure screen is piloted on the tube.

4. Install new seal.

5. Install cover.

(43)Scraper Transmission System - Clean Magnetic Strainer

1. Remove cover.

2. Remove tube, screen and magnets.

3. Remove magnets from screen and wash both in kerosene. Clean magnets with soft cloth or stiff brush. Do not jar magnets.

4. Install screen, tube and magnets as a unit small end of tube out. Be sure screen is piloted on the tube.

5. Install new seal.

6. Install washer and cover.

(44)Tractor-Scraper Fuel Tanks And Filler Caps

Open valves to drain water and sediment.

1. Remove tractor fuel cap.

2. Remove scraper fuel cap.

3. Disassemble caps. Wash parts in clean kerosene. Lightly oil elements and assemble caps.

4. Install caps.