Toro Reelmaster 3550-D Service Manual page 93

Steering/Lift Circuit Testing − Lift Relief Valve (RV1)
Pressure Test (Reelmaster 3555−D and 3575−D)
1. Park machine on a level surface with the cutting units
lowered and reel engage switch OFF. Make sure engine
is OFF and apply the parking brake.
2. Read Precautions For Hydraulic Testing in this sec-
tion.
CAUTION
Before opening hydraulic system, operate all hy-
draulic controls to relieve system pressure and
avoid injury from pressurized hydraulic oil. See
Relieving Hydraulic System Pressure in the Gen-
eral Information section of this chapter.
3. Gain access to hydraulic lift control manifold from be-
low front of machine.
4. Thoroughly clean test port (G) on the right side of the
lift control manifold (Fig. 38). Access to test port can be
obtained from below the right side of the machine be-
hind the front axle. Connect a 5000 PSI (350 bar) pres-
sure gauge to test port.
5. After installing pressure gauge to manifold test port,
start engine and run at idle speed. Check for any hydrau-
lic leakage from test connections and correct before pro-
ceeding with test.
6. Make sure hydraulic oil is at normal operating tem-
perature by operating the machine under load for
approximately ten (10) minutes.
7. Make sure that engine is running at high idle speed.
IMPORTANT: Do not allow pressure to exceed 2500
PSI (172 bar). Hold Lower − Mow/Raise lever in the
raise position only long enough to get a system
pressure reading. Holding the lever in the raise po-
sition for an extended period may damage system
components.
8. Make sure that reel engage switch is OFF and then
pull Lower − Mow/Raise lever rearward to pressurize lift
circuit. While holding lever in the raise (rearward) posi-
tion, watch pressure gauge carefully. As the cutting units
fully raise and the lift relief valve lifts, system pressure
should be approximately 2000 PSI (138 bar).
Reelmaster 3550−D/3555−D/3575−D
FRONT
RIGHT
1. Front axle
2. Lift control manifold
9. Return the Lower − Mow/Raise lever to the neutral
position and stop the engine. Record test results.
10.If measured pressure is incorrect, remove solenoid
relief valve (RV1) on lift control manifold and clean or re-
place valve (see Lift Control Manifold Service in the Ser-
vice and Repairs section of this chapter). Also, if
pressure is low, check for restriction in pump intake line.
lift cylinder internal leakage would also cause low lift cir-
cuit pressure (see Lift Cylinder Internal Leakage Test in
this chapter). If the steering circuit is performing poorly
as well, gear pump (P2) could also be suspected of
wear, damage or inefficiency.
11. After testing is completed, make sure that engine is
stopped and disconnect the pressure gauge from lift
control manifold test port (G).
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2
3
1
Figure 38
3. Test port (G)
Hydraulic System