Service manual

Groundsmaster 3280--D/3320 Hydraulic SystemPage 5 -- 23
Procedure for Lift Cylinder Internal Leakage
Test:
The lift cylinder internal leakage test should be per-
formed if a cutting deck (or implement) raise and lower
problem is identified. This test will determine if the lift cyl-
inders are faulty.
NOTE: Cutting deck raise/lower circuit operation will be
affected by lift cylinder binding, extra weight on the cut-
ting deck (or implement) and/or binding of lift compo-
nents. Make sure that these items are checked before
proceeding with lift cylinder internal leakage test.
1. Park machine on a level surface with the P.T.O.
switch OFF. Set the parking brake and block the front
wheels to prevent machine movement.
2. With the engine running, raise the cutting deck (or
implement) completely. Using blocking or a hoist, sup-
port the cutting deck (or implement) to keep it in the fully
raised position. Turn engine OFF.
3. Place a drain pan under the lift cylinder that is to be
tested for internal leakage. Thoroughly clean the area
around the cylinder return hose at the bottom of the lift
cylinder.
4. Loosen the hose clamp and disconnect the cylinder
return hose from the bottom of the lift cylinder (Fig. 21).
Leave the other end of the return hose connected to the
filter adapter on the transmission.
5. Securely plug the open end of the disconnected lift
cylinder return hose to prevent hydraulic oil leakage or
suction of air by the transmission.
6. Remove all hydraulic oil from drain pan. Make sure
that empty drain pan remains under the open fitting of
the lift cylinder.
7. Start the engine and briefly hold the lift control lever
in the RAISE position to pressurize the lift cylinders.
Turn engine OFF.
8. Check to see if any oil has leaked into the drain pan
from the open fitting of the lift cylinder. If there is any oil
in the drain pan, the lift cylinder has internal leakage and
must be replaced (see Lift Cylinder in the Service and
Repairs section).
9. If the lift cylinder shows no sign of leakage, remove
the plug from the return hose and install the hose on the
lift cylinder fitting. Secure the hose b y tightening the
hose clamp.
10.If needed, repeat steps 3 through 9 for the other lift
cylinder.
11.After testing is completed, remove the s upport from
the cutting deck (or implement). Start engine and oper-
ate lift cylinders through several up and down cycles.
Stop the engine and check for any leakage.
12.Check hydraulic oil level in reservoir (front axle).
1. Lift cylinder 2. Return hose
Figure 21
2
1
Hydraulic
System