1673, 1673, & 1693 DIESEL TRUCK ENGINES Caterpillar

1673C

This chart provides the lubrication and maintenance requirements for your Caterpillar truck engine. Adherence to the instructions and schedules will assure many miles of economical and trouble-free service.

1674

This chart provides the lubrication and maintenance requirements for your Caterpillar truck engine. Adherence to the instructions and schedules will assure many miles of economical and trouble-free service.

1693

This chart provides the lubrication and maintenance requirements for your Caterpillar truck engine. Adherence to the instructions and schedules will assure many miles of economical and trouble-free service.

Air Cleaner (Engine)

The engine may be equipped with a dry-type or an oil-bath air cleaner. Service the engine air cleaner at regular intervals determined by dust conditions.

If equipped with a dry-type air cleaner, a service indicator is usually mounted on the dash panel. A colored piston showing in the window indicates need for service. Clean or replace filter element. Replace dry-type filter element at least once a year. After servicing, reset indicator by pushing on piston plunger.

With an oil-bath cleaner, clean the bottom of the pan with solvent or clean diesel fuel. Fill with engine oil to level indicated by mark on pan. When servicing filter, clean the air pipe inlet cap and wash screens in solvent. Dry thoroughly before installing.

NEVER SERVICE THE AIR CLEANER WHILE THE ENGINE IS RUNNING.

Air Cleaner (Air Compressor)

The time to replace the air compressor air cleaner (on engines so equipped) is determined by inspection. Inspect at intervals given in the Lubrication and Maintenance charts. Install a new element if plugged or oil soaked. Replace element every 20,000 miles (32 000 km) regardless of condition.

Battery

Test the battery electrolyte, at each oil change, with a hydrometer. Always test battery before adding water. A specific gravity difference exceeding .050 between cells indicates the battery may soon need replacing.

Maintain water level 3/8" (9.5 mm) above the separators or insulators. Do not overfill the battery.

The make-up water must be one of the following (in order of preference).

1. Distilled water

2. Odorless, tasteless drinking water

3. Iron free water

Belt Adjustment

Check new belts for adjustment after the first 500 to 1000 miles (800 to 1600 km) of use, thereafter annually. To check belts, apply 25 lbs. (11 kg) force midway between pulleys. Correctly adjusted belts will deflect 1/2 to 3/4 inch (13 to 19 mm).

Cooling System

Show/hide table

INHIBITOR CONTAINS ALKALI. Avoid contact with eyes. Avoid prolonged or repeated contact with skin. Do not take internally. In case of contact, immediately wash skin with soap and water. For eyes, flush with large amounts of water for at least 15 minutes. CALL PHYSICIAN. KEEP OUT OF REACH OF CHILDREN.

Before placing the engine in operation, make sure a 3% concentration of Caterpillar Corrosion Inhibitor or equivalent has been added to the cooling system. This 3% concentration must be maintained in cooling systems which are filled with water and systems protected with ethylene glycol antifreeze mixture, regardless of antifreeze concentration.

Every 3 months, 500 service hours or 25,000 miles (40,000 km) whichever occurs first, add corrosion inhibitor to maintain the recommended 3% concentration.

Refer to the application chart on the container for initial fill and maintenance fill amounts.

(Refer to Lubrication and Maintenance charts for location of water drains.)

Determine the highest point in the engine portion of the cooling system. Remove a plug or loosen a line as close to this point as possible. Fill the cooling system until a solid stream of coolant comes from the opening. (Stop the filling procedure several times to allow the level to stabilize.) Install the plug and fill the system to the proper level. Start the engine and allow it to idle several minutes. Add coolant as necessary. Warm water in the top tank is a good indication that the system is full.

THERMOSTAT: The opening temperature of the regulator (bench test in atmospheric pressure) should be approximately 165 ± 1°F (74 ± 1°C). The regulator should be fully open at approximately 180°F (85°C).

FAN PULLEY BEARING: Use a short fiber grease, No. 2 Grade for most temperatures, or No. 0 or No. 1 for extremely low temperatures. Lubricate through fitting until grease appears at the relief valve. Wipe off excess grease.

WATER PUMP: Use a short fiber grease, No. 2 Grade for most temperatures, or No. 0 or No. 1 for extremely low temperatures. Wipe surrounding area with a clean rag. Lubricate through fitting until lubricant appears at the end of the shaft for the 1674, or at the relief fitting on the 1693.

Crankcase

The Lubrication and Maintenance charts list the normal oil change periods as determined by fuel sulphur content. (Make an initial oil and filter change after the first 500 miles of operation for reconditioned engines.)

OIL DRAIN: Drain the crankcase while the engine is warm and stopped. Remove filler cap and drain plug.

NOTE: 1693 Engines with BrakeSaver, drain the oil cooler.

FILTER CHANGE: Change oil filter at each oil change period.

Spin-on Type Filter (1693): Unscrew and discard filter. Be sure to remove filter gasket from the filter base. Put a thin coat of engine oil on the new filter gasket and install new filter. Tighten the filter by hand until gasket contacts base, then tighten 3/4 turn more.

Cartridge Type Filter (1673, 1674 and earlier 1693): Remove drain plug from filter housing and allow oil to drain. Loosen bolt on filter base and remove the housing and filter element. Wash the inside of the filter housing and install a new Caterpillar filter element. Install new seal if necessary.

BREATHER: Remove and wash the entire breather with clean solvent or diesel fuel.

OIL FILL: Install all drain plugs and fill crankcase. Operate engine until oil is warm and check for leaks. Check engine oil level to be sure it is at the FULL mark on the dipstick.

Priming Procedure

If air is trapped in the fuel system, the diesel engine will either not start, or will misfire. Then it is necessary to prime the system. A fuel priming pump is located on the engine.

TO PRIME THE SYSTEM:

1. Be sure the fuel line valve is open and the engine shut-off control is off.

2. Open the fuel filter vent valve on fuel filter housing.

3. Unlock the fuel priming pump.

4. Operate pump plunger in and out until the fuel flow from the vent is continuous and free of bubbles.

5. Close the vent valve.

6. Move governor control to the shut-off position and loosen fuel line nuts (one at a time) at the pump housing.

7. Operate priming pump until clear fuel flows from fuel pump. Tighten fuel line nut.

8. Repeat for each fuel pump.

9. Lock fuel priming pump.

(If engine continues to misfire or smoke, further bleeding is necessary. With engine running, loosen fuel line nuts at the injectors, one at a time, and allow fuel to run until free of air bubbles. Tighten fuel line nut.)

Tachometer Drive

Use a short fiber grease, No. 2 Grade for most temperatures, or No. 0 or No. 1 for extremely low temperatures. Wipe surrounding area with a clean rag before removing plug. Remove plug. Install grease fitting. Apply two strokes of lubricant through the fitting. Remove grease fitting. Replace plug.

Governor Control Cross Shaft Bearings (1673)
Engines Before 69D3625)

Use a short fiber grease No. 2 Grade for most temperatures, or No. 0 or No. 1 for extremely low temperatures. Apply 1 stroke of lubricant through fitting at each end of shaft.

Valve Adjustment

1673C

Make valve adjustment with engine stopped and cold. Remove the flywheel timing cover and rotate flywheel in direction of engine rotation until "TC 1-6 cyl" mark aligns with timing pointer. Remove valve cover and observe position of valves to determine if No. 1 or No. 6 piston is on compression stroke. Both the inlet and exhaust valves will be closed on compression stroke.

1. With No. 1 piston at TDC on compression, check lash on exhaust valves for cylinders 1, 3 and 5, and inlet valves for cylinders 1, 2 and 4.

2. To adjust, loosen valve adjusting locknut and turn adjusting screw to allow feeler gauge to pass between top of valve stem and the valve rocker arm.

3. Set lash at .015" (0.38 mm) for inlet and .025" (0.63 mm) for exhaust valves.

4. Tighten adjusting screw locknut and check lash clearance.

5. Turn flywheel 360° in direction of engine rotation. Align flywheel timing mark with pointer. No. 6 cylinder will be at TDC compression stroke (valves closed).

6. Check lash on exhaust valves for cylinders 2, 4 and 6, and inlet valves for cylinders 3, 5 and 6. Adjust valves if necessary.

1674

Make valve lash adjustment with engine stopped. TDC of the No. 1 piston on the compression stroke is the reference point. The No. 1 piston will be at TDC when the No. 1 and No. 6 flywheel timing mark aligns with the timing pointer. Compression stroke is when all the No. 1 piston valves are closed.

1. With No. 1 piston at TDC compression stroke, adjust lash on 1, 3 and 5 exhaust and 1, 2 and 4 inlet valves.

2. Turn adjusting screw counterclockwise 2 clicks or more to provide clearance between rocker assembly and valve.

3. Turn adjusting screw clockwise to obtain zero lash. There should be no free rocker movement or adjusting screw button lateral movement.

NOTE: The adjusting screw button can still be rotated by finger pressure even when it is in contact with valve stem and clearance is zero. Turning the adjusting screw clockwise beyond this point will force the valve off its seat, and final lash setting will be incorrect.

4. To adjust, turn adjustment screw counterclockwise 10 clicks (.020") (0.51 mm) for the exhaust valves and 4 clicks (.008") (0.20 mm) for the inlet valves. (One click is equal to .002") (0.05 mm).

5. Turn crankshaft 360° clockwise, (direction of normal rotation) viewing from front. Align flywheel timing mark with timing pointer.

a) Adjust 2, 4 and 6 exhaust .020" (10 clicks).

b) Adjust 3, 5 and 6 inlet .008" (4 clicks).

1693

Make valve lash adjustment with engine stopped and cold. TDC of the No. 1 piston on the compression stroke is the reference point. No. 1 piston is at TDC compression stroke when the No. 1 and No. 6 flywheel timing bolt aligns with the threaded timing hole in the flywheel and No. 1 valves are closed.

1. With No. 1 piston at TDC compression stroke, adjust lash on 1, 3 and 5 exhaust and 1, 2 and 4 inlet valves.

2. Turn cam follower on valve being adjusted until the slanted hole in the follower faces the center of the engine.

3. Insert a Phillips screwdriver in the slanted hole and turn screwdriver clockwise to increase valve lash or counterclockwise to decrease the valve lash. With a clearance gauge measure valve lash between the cam follower and the cam. Correct valve lash is .030" (0.76 mm) for exhaust valves and .018" (0.45 mm) for inlet valves.

4. Turn crankshaft 360° clockwise. Align flywheel timing marks with timing pointer.

5. Adjust lash on 2, 4 and 6 exhaust and 3, 5 and 6 inlet valves.

Brakesaver Operation Instructions

1693

The 1693 BrakeSaver provides auxiliary braking to control speed during periods of deceleration or during decent of long grades. Governing the deceleration or downgrade speed of a vehicle through the use of the BrakeSaver results in greater safety and reduced wear on brake linings and brake drums. It also maintains preparedness of the service brakes for emergency or immediate stop requirements.

Maintenance

The Caterpillar-built BrakeSaver for 1693 Truck Engines is similar to a stalled fluid coupling, transforming the rolling energy of the vehicle-in-motion into heat which is dissipated through the engine cooling system.

The BrakeSaver utilizes the engine oil and cooling systems and eliminates the need for additional oil or cooling systems. Make a frequent visual inspection of coolant and oil lines, and check for leakage and deterioration of hoses. If an oil or water leak develops do not operate the engine until proper repairs can be made.

Scheduled maintenance on the BrakeSaver or additional engine maintenance is not required.

NOTE: Crankcase lubricating oil capacity is 58 qts. (55 litres). See Lubrication and Maintenance Instructions in Operation Guide for service intervals. At oil change intervals, fill crankcase to proper level - operate engine until oil is warm and check for leaks. Check engine oil level to be sure it is at full mark on dipstick.

Controls And Gauges

Operating controls include a selector switch (usually located on the dash board) for selecting automatic or manual control and the hand operated manual control lever (usually located on the steering column) for manually actuating the BrakeSaver.

NOTE: The 1693 BrakeSaver is not an emergency or quick stop brake. Allow a 2 to 3 second delay for full engagement and full disengagement. Use service brakes for quick stops.

CONTROL SELECTOR: With the control selector in the Automatic-Manual position the BrakeSaver will actuate automatically when the accelerator is released and the clutch is engaged (pedal up). The hand operated control has no effect on the BrakeSaver when automatically engaged, however, the system can be manually activated with the manual control lever if the automatic control circuit should fail.

When the selector switch is in the manual position, or in installations not equipped with the selector switch, the BrakeSaver can be actuated only by the hand operated manual control lever.

MANUAL CONTROL LEVER: The hand operated control lever, usually mounted on the steering column, provides a smooth modulated application of the BrakeSaver to apply any desirable retarding of the vehicle up to engine rating. This controlled modulation of actuating the BrakeSaver is especially desirable in slippery road conditions. Increasing or decreasing the BrakeSaver action is accomplished by moving the control lever.

NOTE: For maximum BrakeSaver effectiveness select proper gearing to keep the engine RPM as close to rated speed as possible.

The engine oil pressure gauge indicator will momentarily drop as the BrakeSaver is engaged. This drop in pressure is normal and does not indicate a malfunction.

MANUAL CONTROL LEVER

GAUGES: The BrakeSaver control air pressure gauge indicates air pressure at the BrakeSaver control valve. Air pressure should not exceed 40 PSI (275 kPa).

If the indicator shows reduced or no pressure, stop the vehicle or operate at reduced speed. Control vehicle stopping with proper downshifting and service brakes until proper repairs are made.

The BrakeSaver oil temperature gauge indicator should register in the NORMAL (green) range. If indicator moves to the red range, move the BrakeSaver manual control lever to the OFF position and operate vehicle with service brakes only, or stop the vehicle and let the engine idle until the oil temperature registers in the NORMAL range.

NOTE: To prevent heat build-up, do not leave the BrakeSaver in operation when engine is idling while parked. Place the control selector switch in manual position and the manual control lever in the OFF position.