MTS Hydraulic Power Unit Model 506-92 - Manual (Page 25)

Service 3-13
Water control
adjustment 1. Start this procedure when the temperature gage shows that the
hydraulic fluid is below 90
°
F (32
°
C).
2. Start the HPU.
3. Make sure the square shaft on top of the water regulating valve is
turned fully counterclockwise to shut off water flow.
4. Monitor the temperature gage as the hydraulic fluid heats up.
5. When the fluid temperature reaches approximately 120
°
F (49
°
C),
turn the adjustment screw clockwise until water starts to flow.
Then turn this screw counterclockwise until water flow stops.
6. If the fluid temperature does not reach 125
°
F (52
°
C) turn the screw
a half-turn counterclockwise and note the effect after 15 minutes. If
the temperature exceeds 125
°
F (52
°
C), turn the screw clockwise.
7. After adjustments are completed, turn the square shaft on top of the
water regulating valve fully clockwise for full cooling water flow.
3 . 2 . 3 Low-Level Switch Adjustment
VW-G051
locknut
top of
reservoir
The low fluid-level switch turns off the HPU if there is an appreciable
loss of hydraulic fluid. The factory-adjustment coincides with the
bottom of the fluid level gage and does not normally require
readjustment. Perform the following steps if readjustment is necessary.
1. With the HPU turned off, fill the reservoir to the correct fluid level.
2. Turn on the HPU and apply high pressure.
3. See the figure on the left. Loosen the hand locknut on the stem of
the switch, and slowly raise the switch until the Low Fluid Level
indicator lights.
4. Lower the switch about 1.5 in. (38 mm).
5. Tighten the locknut.
6. Reset any applicable interlock circuits.