Hy-tec Hydraulics 9
2
j.
1
Pressure Testing the Valve Unit Before Assembling to the Housing
a. Clean the control valve with help of air & make it dry. 7 8
b. Remove external jack tapping plug. Fit special tool MST-H1/2-HD-12 & MST-H1/2HD-11
3 4 5
6
1.
Main Spool Valve Bore
2.
Relief Valve Bore
3.
Plug Connecting Check Valve to Control Valve
4.
Plug Connecting Cylinder to Control Valve
5.
Lowering Port Connecting Control Valve Spring chamber to Tank
6.
Bypass Tank Port
7.
Plug Connecting Pump, Relief Valve & Control Valve
8.
Port Conecting Regulator Bore to reservor
9.
Regulator Valve Bore
h. Position Control Valve Lift — Lower Test Locate the position control stop at about mid range. Fully raise the lift arms then lower until the control lever is against the stop.
c.
Connect the hand pump (injecter tester) to the external jack tapping.
Measure the height from the centre line of the lower link ball ends to the ground. Fully lower the lift arms then raise until the control lever is against the stop and on the same side of the stop as in the first test. Measure the height of the ball ends from the ground. If these two measurements differ by more than 25.4mm. The control valve spool may sticky. i.
Noise
d. Screw in the isolator valve.
There should be no noise from any part of the hydraulic system apart from a slight hiss caused by oil flow.
e. Hole the spool at the full lift position (inside).
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