PR-750B PAVEMENT PROFILER Service When Required Caterpillar

Check the following and service as required:

a. Water spray system filters and spray nozzles.

b. Engine power take-off housing oil level.

c. Radiator and oil cooler cores.

d. Engine air cleaners.

e. Pump drive gearbox oil level.

f. Hydraulic oil level.

g. Track charge pressure filter.

h. Control (auxiliary) hydraulic filter and the conveyor return (main) hydraulic filter.

i. Cutter drive belt bands.

j. Cutter sheave oil levels.

k. Cutter and track planetary gear reducer oil levels.

l. Fuel filters.

m. Leg barrels and leg yokes.

n. Air compressor and air system.

Checking The Water Spray System Filters

The water spray system has two pressure gauges that should be checked periodically during operation and as part of the daily service. The gauges, mounted on the inlet and outlet of the water system filters, should be checked with the spray system operating. If the pressure gauge on the outlet of the filters falls below 40 psi (276 kPa) or the difference between the two pressures is more than 20 psi (138 kPa) the filter elements should be changed. If the pressure gauge on the inlet to the filters falls below 55 psi (379 kPa), the spray system pump should be checked.

To change a water filter:

1. Check the pressure gauges to be sure there is no pressure in the system.

2. Unscrew the filter body from the filter head.

3. Remove the element.

4. Clean the inside of the body.

5. Place a new element in the body and install the body on the head.

Checking The Water Spray System Nozzles

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NOTICE
IT IS EXTREMELY IMPORTANT THAT THE SPRAY NOZZLES OPERATE PROPERLY AT ALL TIMES. IF THEY DO NOT, LARGE AMOUNTS OF DUST WILL LEAVE THE CUTTER AREA AND BE DRAWN INTO THE RADIATOR AND OIL COOLER, CAUSING OVERHEATING OF THE ENGINE AND/OR HYDRAULIC OIL.

To check the spray nozzles:

1. Open the cutter door and install the chain.

2. SHUT THE ENGINE DOWN and then remove the nozzle.

3. With the engine running, move the spray bar switch to "Start".

4. Visually check the cutter spray pattern from the front. Check the conveyor spray nozzles from the top of the lower conveyor.

5. If a nozzle is not spraying properly, SHUT THE ENGINE DOWN and then remove the nozzle.

6. Disassemble, clean and reassemble the nozzle.

7. Reinstall the nozzle and check its operation as in 3 and 4 above.

Checking The Engine Power Take-Off Housing Oil Level

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INADVERTENT ENGAGEMENT OF THE CUTTER COULD CAUSE PERSONAL INJURY. SHUT THE ENGINE DOWN, LOCK THE CUTTER CONTROL AT "OFF", AND REMOVE THE KEY FROM THE IGNITION SWITCH.

1. Remove the check plug.

2. If the lubricant is not at check plug level, remove the breather and add lubricant until check plug level is reached.

3. Replace the breather and check plug.

Checking The Radiator And Hydraulic Oil Cooler Cores

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INADVERTENT STARTING OF THE ENGINE COULD CAUSE PERSONAL INJURY. SHUT THE ENGINE DOWN AND REMOVE THE KEY FROM THE IGNITION SWITCH.

Check that the radiator and oil cooler are clear of any obstructions to air flow through the cooling fins. Any rags, paper, mud, DUST, bugs, etc. that may obstruct the air flow must be removed. Carefully straighten any bent fins.

Each of the two engine air cleaners is equipped with an indicator that shows a red signal when the main element should be serviced. If the red signal is locked in view, the main element should be serviced as soon as possible to prevent possible engine damage. See "Changing the Engine Air Cleaner Elements" below for procedures.

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INADVERTENT STARTING OF THE ENGINE COULD CAUSE PERSONAL INJURY. SHUT THE ENGINE DOWN AND REMOVE THE KEY FROM THE IGNITION SWITCH.

Each air cleaner also has a dust cup that collects the dust from the pre-cleaner. Empty the dust cup when the dust builds up to within one and one-quarter inches (3.2 cm) from the top of the cup. Remove and inspect the dust cup daily until a regular service interval can be established.

When replacing the dust cup, be sure a seal is made between the cup and the body to maintain high pre-cleaner efficiency. Replace the gasket if it is not smooth and clean.

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NOTICE
THIS IS A DRY TYPE AIR CLEANER - DO NOT USE OIL.

Changing The Engine Air Cleaner Elements

The main element should be cleaned or replaced with a new element anytime the air cleaner red indicator is locked in view. Replace the main element after three cleanings or one year of use, whichever occurs first. Change the safety element every third time the main element is cleaned or replaced. (See the Service Manual for cleaning procedures.)

Although it is possible to clean the safety element using the procedures described for the main element, it is not recommended except in an emergency situation. Maximum engine protection is achieved by replacing the plugged safety element with a new element.

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INADVERTENT STARTING OF THE ENGINE COULD CAUSE PERSONAL INJURY. SHUT THE ENGINE DOWN AND REMOVE THE KEY FROM THE IGNITION SWITCH.

To replace the main element:

1. STOP THE ENGINE, clean the dust off the access cover and unlatch it.

2. Remove the access cover and main element. DO NOT REMOVE THE SAFETY ELEMENT.

3. Immediately inspect the main element for any dust streaks on the inside. If there are any dust streaks, the element is damaged. THROW IT AWAY.

4. Inspect the main element gasket. If the element gasket is not smooth and flat or is damaged in any way that might allow dust to get by, THROW THE ELEMENT AWAY.

5. Install a new or cleaned main element and tighten the wing nut securely.

6. Install the access cover.

To replace the safety element:

1. STOP THE ENGINE, clean the dust off the access cover and remove it.

2. Loosen the wing nut and remove the main element.

3. Remove the locking pin from the nut, and remove the nut that secures the safety element.

4. Remove the safety element and clean out any dust dislodged into the cleaner outlet.

5. Install the new safety element.

6. Inspect the gasket washer on the nut and replace it if a good air seal cannot be guaranteed.

7. Tighten the nut securely and replace the locking pin.

8. Install the main element and tighten the wing nut securely.

9. Install the access cover.

Checking The Pump Drive Gearbox Oil Level

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INADVERTENT STARTING OF THE ENGINE COULD CAUSE PERSONAL INJURY. SHUT THE ENGINE DOWN AND REMOVE THE KEY FROM THE IGNITION SWITCH.

1. Remove the check plug.

2. Add oil, if necessary, until the oil reaches check plug level.

3. Replace the check plug.

Checking The Hydraulic Oil Level

The hydraulic oil tank is equipped with a sight gauge for easy checking of the oil level which should be maintained within 2 to 3 inches (5.1 to 7.6 cm) of the top of the gauge. If the oil level is low, use the replenishing hand pump to transfer oil from the replenishing tank to the main tank. Refill the replenishing tank 2/3 to 3/4 full with new water-free hydraulic oil conforming to the specification on page 5-2. Do not overfill either tank, allow for expansion of the oil.

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NOTICE
THE HYDRAULIC OIL LEVEL MUST BE KEPT NEAR THE TOP OF THE SIGHT GAUGE OR THE HYDRAULIC COMPONENTS MAY BE DAMAGED.

Checking The Track Charge Pressure Filter

The filter is equipped with an indicator to show when the element should be changed. The indicator will show green when a new filter element is installed. As the filter element becomes clogged, the green will be replaced by red. When the indicator shows all red, the filter should be replaced (see below for procedures).

Changing The Track Charge Pressure Filter Element

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AT OPERATING TEMPERATURES THE HYDRAULIC OIL AND OIL TANK CAN CAUSE SERIOUS BURNS. LET THE MACHINE STAND IDLE UNTIL THE HYDRAULIC OIL HAS COOLED AND THE OIL TANK IS COMFORTABLE TO TOUCH.

1. Unscrew the element from the filter head. If the filter has a gasket between the element and the head, be sure the gasket comes off with the element.

2. Coat the gasket or O-ring of the new element with clean hydraulic oil.

3. Screw the element onto the filter head until the element contacts the head.

4. Turn the element 1/2 to 3/4 turn more.

5. Check the hydraulic oil level and add oil as necessary.

Checking The Control (Auxiliary) Hydraulic System Pressure Filter

The control system filter is equipped with a pressure differential indicator to show when the element should be changed. The indicator will be flush with the indicator case when a new filter element is installed. As the filter element becomes clogged, the red indicator will "pop up" into view.

Two persons are required to check the condition of the control system filter, one to operate the controls and one to watch the filter indicator.

1. Be sure the hydraulic oil temperature is at or above 140°F (60°C).

2. Set the engine at high idle.

3. Actuate a steering or elevation control valve and watch the auxiliary pressure gauge on the forward console for a drop in pressure.

4. Watch the filter indicator while the control valve is actuated. If the indicator signal "pops up" into view, CHANGE THE FILTER ELEMENT. See below for procedures.

Changing The Control (Auxiliary) Hydraulic System Filter Element

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AT OPERATING TEMPERATURES THE HYDRAULIC OIL AND FILTER CAN CAUSE SERIOUS BURNS. LET THE MACHINE STAND IDLE UNTIL THE HYDRAULIC OIL HAS COOLED AND THE FILTER IS COMFORTABLE TO TOUCH. BE SURE HYDRAULIC OIL PRESSURE IS RELIEVED BY ACTUATING A STEERING OR ELEVATION CONTROL VALVE UNTIL THE CYLINDER WILL NOT RESPOND IN EITHER DIRECTION.

1. Remove the filter bowl and element. Throw the element away and empty the bowl.

2. Flush the bowl with clean solvent and blow it dry with filtered air.

3. Insert a new element into the bowl and install the bowl on the filter head.

4. Loosen the pressure line at the outlet port in the filter head.

5. Leave the ignition switch at "Off" and crank the engine with the starter until air-free hydraulic oil comes from the filter outlet port.

6. Tighten the pressure line at the outlet port.

Checking The Conveyor Return (Main) Hydraulic Filter

The conveyor return filter is equipped with a system bypass pressure gauge to show when the element should be changed.

1. Be sure the hydraulic oil temperature is at or above 140°F (60°C).

2. Set the engine at high idle.

3. Observe the system bypass pressure gauge. If the gauge reads 80 psi (552 kPa) change the filter element (see below for procedures).

Changing The Conveyor Return (Main) Hydraulic Filter Element

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AT OPERATING TEMPERATURES THE HYDRAULIC OIL AND FILTER CAN CAUSE SERIOUS BURNS. LET THE MACHINE STAND IDLE UNTIL THE HYDRAULIC OIL HAS COOLED AND THE FILTER IS COMFORTABLE TO TOUCH.

1. Remove the filter bowl and element. Throw the element away and empty the bowl.

2. Flush the bowl with clean solvent and blow it dry with filtered air.

3. Insert a new element into the bowl and install the bowl on the filter head.

4. Tighten the bowl to 75 lb-ft (102.4 Nm) of torque.

Checking The Cutter Drive Belt Bands

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INADVERTENT ENGAGEMENT OF THE CUTTER COULD CAUSE PERSONAL INJURY. SHUT THE ENGINE DOWN, LOCK THE CUTTER CONTROL AT "OFF", AND REMOVE THE KEY FROM THE IGNITION SWITCH.

1. Check the belt bands for breaks, cracks, burned spots, separation from the tie band, or excessive wear. Check the tie bands for fraying, holes or blisters. If the condition of any belt band is questionable, replace all the belt bands in that set.

2. If the belt bands are glazed, apply a belt dressing to the belt bands.

3. If the belt bands have been slipping, adjust the tension as described below.

Adjusting The Cutter Drive Belt Bands

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INADVERTENT ENGAGEMENT OF THE CUTTER COULD CAUSE PERSONAL INJURY. SHUT THE ENGINE DOWN, LOCK THE CUTTER CONTROL AT "OFF", AND REMOVE THE KEY FROM THE IGNITION SWITCH.

1. Open the belt cover.

2. Pump the tensioner until the piston rod contacts the angled plate on the takeup.

3. Loosen the four bolts that hold the takeup in place until the takeup can easily slide on the support but is not loose.

4. Pump the tensioner until the pressure gauge indicates 7000 to 7500 psi (48 265 to 51 713 kPa), hold the pressure and tighten the four 3/4" (1.9 cm)-10 NC bolts that hold the take-up in place.

5. Loosen the jam nuts on the two takeup bolts, turn the takeup bolts until they firmly contact the angled plate, then hold each bolt and tighten the jam nut.

6. Close the belt cover.

Checking The Cutter Sheave Oil Levels

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INADVERTENT ENGAGEMENT OF THE CUTTER COULD CAUSE PERSONAL INJURY. SHUT THE ENGINE DOWN, LOCK THE CUTTER CONTROL AT "OFF", AND REMOVE THE KEY FROM THE IGNITION SWITCH.

The oil level must be checked in the upper drive sheave takeup housing and the lower driven sheave at the right end of the cutter. The machine must be reasonably level while checking the oil levels.

1. Open the cutter belt cover.

2. Remove the check plug. If the oil trickles from the check plug port, reinstall the check plug. If a large amount of oil flows from the port, allow the oil to drain, then reinstall the check plug. If no oil is apparent at the check plug port add oil as described below.

3. To add oil, remove the breather or plug, or disconnect the hose, then add oil through the port until the oil reaches check plug level. Wait several minutes for the oil level to even out throughout the sheave, then add more oil.

4. After the correct oil level is assured, install the check plug and breather or hose.

5. Close the cutter belt cover.

Checking The Cutter Planetary Gear Reducer Oil Level

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INADVERTENT ENGAGEMENT OF THE CUTTER COULD CAUSE PERSONAL INJURY. SHUT THE ENGINE DOWN, LOCK THE CUTTER CONTROL AT "OFF", AND REMOVE THE KEY FROM THE IGNITION SWITCH.

The machine must be on level ground when the oil level is checked.

1. Open the cutter belt cover.

2. Remove a bolt from each cover plate and loosen the other bolt, use the cutter auxiliary drive motor to position the plugs with the check plug 2 inches (5.1 cm) below the cutter centerline, then remove the check plug. If oil trickles from the check plug port, reinstall the check plug. If a large amount of oil flows from the port, allow the oil to drain, then reinstall the check plug. If no oil is apparent at the check plug port, add oil as described below.

3. To add oil, remove the fill plug, then add oil through the fill plug port until the oil reaches check plug level. Wait several minutes for the oil level to even out throughout the reducer, then add more oil.

4. After the correct level is assured, install the check plug, the fill plug and the cover plates.

5. Close the cutter belt cover.

Checking The Track Planetary Gear Reducer Oil Levels

1. Position the machine so that the fill plug in a gear reducer is at the top of the case and the check plug is at the same level as the center of the case.

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INADVERTENT ENGAGEMENT OF THE TRACK DRIVE SYSTEM COULD CAUSE PERSONAL INJURY. SHUT THE ENGINE DOWN AND REMOVE THE KEY FROM THE IGNITION SWITCH.

2. Allow time for the oil to settle to the bottom of the gear reducer, then remove the check plug.

3. If the oil does not trickle from the check plug port, remove the fill plug and add oil until check plug port level is reached.

4. Install the check plug and fill plug.

5. Repeat steps 1 through 4 for the other tracks.

Checking The Engine Fuel Filters

The fuel pressure gauge should register in the NORMAL - green or approximately 30 psi (207 kPa) - range with the engine running and with clean primary and final fuel filter elements. As the filter elements become clogged the gauge indicator will gradually move toward the OUT - red or approximately 20 psi (138 kPa) range. If the gauge indication reaches the OUT range, the primary fuel filter element should be removed and cleaned (see below). If the indication is still in the OUT range after cleaning the primary element, replace the final fuel filter elements (see page 5-28).

Cleaning The Engine Primary Fuel Filter Element

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DIESEL FUEL IS VOLATILE AND COULD IGNITE OR EXPLODE, CAUSING SERIOUS BURNS AND INJURIES FROM FLYING OBJECTS. NEVER SMOKE OR HAVE AN OPEN FLAME WHILE WORKING ON THE FUEL SYSTEM.

1. SHUT THE ENGINE DOWN and close the fuel shutoff valve.

2. Loosen the nut on the filter cover and lower the filter case.

3. Remove the element and wash it in clean solvent or diesel fuel.

4. Reinstall the element and open the fuel shutoff valve.

5. If the engine will not start or misfires, prime the fuel system as described on page 5-28.

Replacing The Engine Final Fuel Filters

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DIESEL FUEL IS VOLATILE AND COULD IGNITE OR EXPLODE, CAUSING SERIOUS BURNS AND INJURIES FROM FLYING OBJECTS. NEVER SMOKE OR HAVE AN OPEN FLAME WHILE WORKING ON THE FUEL SYSTEM.

1. SHUT THE ENGINE DOWN and close the fuel shutoff valves.

2. Unscrew and remove the filters.

3. Clean the gasket sealing surfaces on the filter bases.

4. Lubricate the new filter gasket with clean diesel fuel.

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NOTICE
DO NOT POUR FUEL INTO THE NEW FILTER ELEMENT BEFORE INSTALLING. PRIME THE SYSTEM AS DESCRIBED BELOW.

5. Tighten the filters by hand until the gasket contacts the base, then tighten 1/2 to 3/4 turn more.

Priming The Engine Fuel System

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DIESEL FUEL IS VOLATILE AND COULD IGNITE OR EXPLODE, CAUSING SERIOUS BURNS AND INJURIES FROM FLYING OBJECTS. NEVER SMOKE OR HAVE AN OPEN FLAME WHILE WORKING ON THE FUEL SYSTEM.

1. Be sure the fuel shutoff valve is open and the engine ignition switch is at "Off".

2. Unlock the fuel priming pump.

3. Operate the priming pump until increased resistance is felt.

4. Lock the fuel priming pump.

5. Start the engine.

If the engine fails to start or continues to misfire or smoke, further bleeding is necessary. With the engine running, or with the use of the priming pump, loosen the fuel line nuts one at a time several times in succession and allow fuel to flow until free of air bubbles. Tighten the fuel line nuts.

Checking And Lubricating The Leg Barrels And Leg Yokes

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THE MAINFRAME COULD FALL AND CAUSE PERSONAL INJURY. LOWER THE SUPPORT LEGS INTO PLACE WHENEVER WORKING UNDER THE MACHINE.

Check that there is lubricant present on all surfaces of the square tube portion of the leg yokes. If not:

1. Start the engine, raise the mainframe to the upper limit, lower the support legs, then lower the mainframe until the support legs are held in position. SHUT THE ENGINE DOWN.

2. Using a wooden or plastic paddle apply a thin coating of lubricant to each leg yoke.

3. Start the engine, raise the mainframe to the upper limit, stow the support legs, then lower the mainframe.

Servicing The Air Line Lubricator

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AIR ESCAPING FROM THE SYSTEM COULD CAUSE PERSONAL INJURY. STAY CLEAR WHEN DRAINING THE AIR RESERVOIR.

1. Open the drain valve at the bottom of the reservoir and the petcock at the bottom of the filter regulator. Let the air flow until accumulated moisture is removed.

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REMOVING THE LUBRIAVSOR BOWL WHEN THE SYSTEM IS PRESSURIZED COULD CAUSE PERSONAL INJURY. CLOSE THE AIR SYSTEM SHUTOFF VALVE AND DISCHARGE ALL AIR PRESSURE FROM THE LUBRIAVSOR.

2. Check the lubricator oil level and add 10W non-detergent engine oil as needed. Before adding oil, close the shutoff valve and open the petcock at the bottom of the filter regulator until all air pressure is discharged.