PR-450 PAVEMENT PROFILER During Operation Caterpillar

It is extremely important that the hydraulic oil temperature be checked periodically during operation. Continuous operation of the machine with high hydraulic oil temperatures will cause rapid wear and failure of pumps and motors.

If the hydraulic oil temperature rises to 210°F (99°C) and remains there or continues to rise, stop the machine and check the return filter indicator. If the indicator is red, the return filter elements are clogged and the hydraulic oil is bypassing the filter AND THE OIL COOLER (see page 2-22). Shut the engine down immediately and change the return filter elements (see page 5-55). If the return filter indicator is not red, shut the engine down and thoroughly clean the exterior surfaces of the hydraulic oil cooler and radiator. Use an air hose to remove any loose material and then, if necessary, use a steam cleaner to remove any remaining material. Also check the condition of the engine coolant and, if the coolant shows signs of system corrosion, flush and clean the cooling system.

Water Spray System

Although it may not appear to be important, the water spray system is one of the key factors to effective machine operation. If the system does not work properly, excessive dust can settle in the radiator and oil cooler and cause the engine or the hydraulic system to overheat, possibly damaging the engine or hydraulic system. It is therefore important that the operator watch for any indication of plugging of the nozzles. If the nozzles appear to be plugging up, the operation should be stopped, the nozzles cleaned (see page 5-24), the strainer screen removed and cleaned (see page 5-32), and the filter element changed (see page 5-22). If the water in the tank is excessively dirty, drain the tank and refill it with clean water.

To avoid needless down time:

1. Always use the cleanest water possible.

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STOP THE MACHINE, SET THE EMERGENCY AND PARKING BRAKE CONTROL AT "APPLY", AND LOCK THE CUTTER CONTROL AT "OFF" BEFORE CHECKING THE WATER PRESSURE GAUGES OR NOZZLES. MOVEMENT OF THE MACHINE OR CUTTER COULD CAUSE SERIOUS INJURIES.

2. Check the water system pressure gauges periodically during the day. If the pressure drop across the filter is more than 20 psi, replace the filter element (see page 5-22).

3. Visually check operation of the spray nozzles periodically during the day.

4. Flush the strainer screen daily by opening the valve on it and allowing the water to flow out for a minute or two.

If the machine is to be parked outside in freezing weather, the water spray system must be drained immediately after stopping operation. See page 5-16 for procedures.

Track Drive System

If during operation the track drive system seems to be responding sluggishly and/or there is a rattling or pinging noise in the track drive pump, stop the machine and check the supply (track drive pump suction) filter indicator. If the indicator is red, the supply filter element is clogged and not allowing enough hydraulic oil to flow to the pump. Shut the engine down immediately and change the supply filter element (see page 5-55). If the supply filter indicator is not red, refer to the Sundstrand Service Manual.

Cutter Belts

New cutter belt sets will stretch when they are first put into operation. If the belt tension is not readjusted as the belts stretch, the belts will start to slip or slip-and-grab, causing the belts to break. If the belts do not break, the slipping will cause overheating, burned spots, and excessive cover wear.

After new belts are installed, check the belt tension (see page 5-45). at the following times:

1. After the first 1/2 hour of operation.

2. After the first 4 hours of operation.

3. After the first day of operation.

4. After the second day of operation.

5. After the first week of operation

6. After the first 200 hours or one month of operation.

Cutting Asphalt

The operator must be particularly alert when cutting asphalt because the physical properties of a given type of asphalt vary considerably with ambient temperatures. When the asphalt is cool it is harder and more brittle, making it easier for the cutter bits to cut. As the asphalt gets warmer it gets soft and gummy, creating a drag on the cutter bits. The possible cutting speed in a given type of asphalt will vary between winter and summer, morning and afternoon, and between shaded and unshaded areas. The operator must be alert for changes in the asphalt and make the required changes in machine settings.

Avoid cutting large amounts of asphalt and then cutting concrete with the same set of bits. Asphalt tends to wear the supporting metal away from around the carbide tip, leaving the carbide center shaft exposed. If the exposed carbide tips then hit concrete, they may break off at the level of the supporting metal. This same problem may be encountered when cutting asphalt overlaid on concrete if the bits occasionally hit the concrete base. Replace the bits anytime the distance from the end of the supporting metal to the holder is 1 1/4" or less.

Caring For The Cutter

The life of the cutter bits will vary greatly with the type of material being cut, the temperature and the speed of operation. Check the length of the bits periodically during the day and be sure they are replaced if they get worn down to a length of 1 1/4" from the tip of the bit to the holder. If the bits are not replaced when required, the holder will start hitting the concrete and will be severely damaged or even cause damage to the cutter.

Uneven bit wear can result from a variety of reasons. One cause is the cutting of long stretches of material that are not as wide as the cutter. Another possible cause is the cutting of asphalt overlaid on concrete in such a way that the cutter bits are hitting concrete on one section of the cutter and hitting only asphalt on another section. If the machine is to be used to cut an accurate cross slope, the cutter bits should be checked for uneven wear and replaced if uneven wear has occured. The machine will not cut an accurate cross slope unless the bits are all the same length.

Checking Calibration Of The Optional Cross Slope Sensor

CROSS SLOPE SENSOR

NOTE: THE CROSS SLOPE SENSOR IS A PRECISION INSTRUMENT THAT IS ACCURATELY CALIBRATED AT THE FACTORY. DO NOT ADJUST OR CHANGE THE POSITION OF THE POINTER, THE ADJUSTMENT GUIDE BLOCK OR THE ADJUSTMENT SHAFT BEARINGS.

The cross slope sensor is accurately calibrated to the cutter before the machine leaves the factory and will not normally require any further adjustment. If the machine is not cutting to the slope set in the slope indicator, the calibration of the cross slope sensor can be checked as follows:

1. Check the cutter bits for even wear. If the bits are not evenly worn, replace all the bits.

2. Position the machine on a level slab or compacted dirt grade, set the emergency and parking brake control at "Apply", lock the cutter control at "Off", and open the cutter doors.

3. Set the slope indicator at "O", the rear elevation automatic mode selector at "Cross Slope" and, if present, the slope control selector valves so they point to the right. Leave the front elevation control mode selector at "Off".

4. Set the cutter control at "On".

5. Use the front and left rear elevation controls to manually lower the mainframe evenly until the cutter bits on the left end of the cutter are just contacting the slab and the mainframe is level fore and aft. If the cutter bits are all just contacting the slab, the cutter is level. Proceed with normal operation of the machine.

6. If the cutter is not level, check the alignment of the pointer on the pendulum assembly and the line on the adjustment guide block. Turn the slope selector as necessary to align the pointer and line.

7. Check to see if the slope indicator is on "O". If not loosen the setscrew in the pulley on the slope indicator shaft, hold the pulley so it will not turn and then turn the slope indicator shaft to set the slope indicator at "O". Tighten the pulley setscrew.

8. Crank the engine long enough for the cross slope system to adjust to the new setting.

9. SHUT THE ENGINE DOWN and recheck the cutter. If the cutter is level, proceed with normal operation of the machine.

10. If the cutter is not level, set an 8 inch mechanic's level (Starret No. 98 with ground and graduated main vial, or equal) on top of the adjustment yoke bracket and parallel to the adjustment shaft.

11. Move the rear elevation control mode selector to "Off" and use the elevation controls to adjust the cutter so that the bits are all just contacting the slab.

12. Turn the nuts on the leveling studs (see page 4-27) as necessary to level the adjustment guide block, tighten the nuts and recheck the level of the guide block.

13. Set the slope indicator at "O" and proceed with normal operation of the machine. If the machine does not cut "Slope Right" or "Slope Left" according to the slope indicator, see "Calibrating the Cross Slope Sensor" in the Maintenance Manual.