Multiquip HTH44T manual Pressure Gauge Hydraulic Pump

HTH44T— MAINTENANCE

Checking Hydraulic Pressure

It should be mentioned that most hydraulic problems are a result of low fluid levels. Before checking any other possibilities, make sure the hydraulic fluid level is half way up the sight glass which is located at the right end of the frame.

Hydraulic pressure can be checked using a pressure gauge (Figure 19) with a range of at least 5,000 psi. Two male diagnostic quick couplers (one for each pump) are located in the elbow fittings (Figure 19) at the front of the pump. It is best to use two gauges simultaneously, but it is possible to use only one gauge and repeat the procedure for each side.

To fully test the hydraulic system, the spiders will need to be locked so that they cannot rotate. This can easily be done by wrapping a chain around an arm on each spider, thus chaining them together in the back of the trowel.

Once the pressure gauges are installed and the spiders chained together, the system can be checked.

With the foot pedal in the idle position and the engine at full speed, the pressure should be 200 to 300 psi. If the pressure is less than 200 psi, the charge system may need to be inspected and/ or serviced. In particular, the suction filter and charge pump relief valve should be checked.The suction filter may be plugged, or the relief valve may be stuck. Either condition may cause low charge pressure.

With the engine at 50% to 70% of full speed, and spiders chained together, slowly depress the foot pedal and read the gauges. The pressure should get to at least 3,100 psi. If the pressure will not attain 3,100 psi, the pump should be inspected and/or serviced by an authorized service representative.

Figure 19. Pressure Gauge (Hydraulic Pump)

HTH44T • RIDE-ON POWER TROWEL — OPERATION & PARTS MANUAL — REV. #8 (03/27/12) — PAGE 23