225B AND 229 TRACK-TYPE EXCAVATORS Every 500 Service Hours or 3 Months Caterpillar

Every 500 Service Hours or 3 Months
1.1. Hydraulic Oil System
2.2. Service the Filters
3.2. Main Filter and Screen
4.2. Pilot System Filter
5.2. Case Drain Filter
6.1. Fuel System
7.2. Service the Fuel System
8.2. Change the Fuel Filter
9.2. Priming the Fuel System
10.2. Tank Cap and Strainer

Hydraulic Oil System

Service the Filters

------ WARNING! ------

At operating temperature, the hydraulic tank is hot and under pressure.

Hot oil can cause burns.

Remove the fill cap only when the engine is stopped, and the cap is cool enough to touch with your bare hand. Remove the fill cap slowly to relieve pressure.


1. Unlatch and open both right side access doors.
2. Pull the latch and open the hydraulic tank cap access cover. The cover opens from the top.
3. Slowly remove hydraulic tank filler cap to relieve system pressure.

Main Filter and Screen

1. Open rear access door on left side.

2. Remove cap from drain valve (1) and attach a hose with a fitting, with a 1 1/16 - 12 internal thread, to the valve.
3. When the hose connection is tightened, keep turning the fitting to open the drain valve.
4. Loosen bleed screw (2) and allow filter to drain. Close drain valve and disconnect hose.
5. Remove filter cover bolts (3). Install 3 bolts in puller holes (4). Pull cover by turning bolts evenly to prevent binding.
6. Remove element and screen. Discard old element.
7. Clean the inside of the filter housing.
8. Wash cover and filter screen in clean non-flammable solvent. Allow to dry.
9. Install new filter element and clean screen.
10. Inspect cover seal. Install new seal if used seal is damaged.

11. Install cover. Tighten bolts evenly to avoid seal damage.
12. Install and tighten bleed screw.
13. Install drain cap.
14. Close the access door.

Pilot System Filter

1. Remove filter housing drain plug and allow oil to drain.

2. Turn nut at top of filter cover and remove cover and used element. Discard element.
3. Clean filter housing.
4. Clean and install housing drain plug.
5. Install a new filter element.
6. Fill housing with clean hydraulic oil.
7. Wash cover in clean nonflammable solvent. Replace cover seal if it is damaged.
8. Install the cover and tighten it to 58 ± 7 N·m (43 ± 5 lb ft).
9. Start and run engine for a few minutes. Inspect for leaks.
10. With the machine level, position the equipment as shown.

Position backhoe linkage on ground with stick and bucket cylinders fully extended. Machine must be level.

Position clamshell on ground in open position with stick cylinder fully extended and machine level.

11. Stop engine and observe oil level sight guage on hydraulic tank.
12. Maintain oil level between the ADD and the FULL marks.

Case Drain Filter

1. Case drain filter is located on front right side of machine, behind boom.

2. Remove filter housing drain plug (1) and allow oil to drain.
3. Loosen filter housing bolt (2) and remove housing and element. Discard used element.
4. Clean inside of filter housing and inspect filter housing base seal. Install new seal if it is damaged.
5. Install new element in filter housing.
6. Install housing and tighten retaining bolt to 52 ± 3 N·m (38 ± 2 lb ft). Clean and install drain plug.
7. Start and run engine at low idle to fill housing. Stop engine.
8. Observe hydraulic oil level. Add if necessary.
9. Close and secure all access doors.

Fuel System

Service the Fuel System

------ WARNING! ------

Pressure air can cause personal injury.

When using pressure air for cleaning, wear a protective face shield, protective clothing and protective shoes.

The maximum air pressure must be below 205 kPa (30 psi) for cleaning purposes.

Use all cleaning solutions with care.

Fuel leaked or spilled onto hot surfaces or electrical components can cause a fire.

Turn the disconnect switch OFF or disconnect the battery when changing fuel filters.



Do not fill fuel filters with fuel before installing them. Contaminated fuel will cause accelerated wear to fuel system parts.

Change the Fuel Filter

------ WARNING! ------

Fuel spilled or leaked onto hot surfaces or electrical components can cause a fire.

Disconnect the batteries (turn the disconnect switch OFF) when changing fuel filters or fuel/water separators.


1. Open the right rear access door. Remove the fuel filter.

2. Clean the filter base. Be sure all of the used filter seal is removed.

3. Coat the seal of a new filter with clean diesel fuel.


Do not overtighten the filter.

4. Install a new filter by hand. When the seal contacts the filter base, tighten 3/4turn more.
5. Prime the fuel system. (Refer to "Priming the Fuel System"). Start the engine and check for leaks.

Priming the Fuel System

1. Open the fuel system bleed valve.

2. Unlock the priming pump plunger and operate the pump.
3. When fuel flows from the bleed valve free of air bubbles, lock the pump and close the bleed valve.

4. To remove air from the fuel injection lines, loosen the line nuts on the fuel injection nozzles 1/2 turn.
5. Move the governor control to low idle position.
6. Crank the engine with the starting motor until fuel, free of air, flows from the lines. Tighten the nuts. Close the access door.

Tank Cap and Strainer

1. Unlatch and open the right side front access door. Pull the latch and open fuel tank fill cap access cover.

2. Remove the fuel tank cap.

3. Remove the strainer from fill opening.
4. Wash the cap and screen in clean, nonflammable solvent. Allow them to dry.
5. Install the clean screen.
6. Inspect the cap gasket. Replace the cap if it is damaged. Install the cap.