Toro 3550-D Lawn Mower User Manual


 
Reelmaster 3550−D Hydraulic SystemPage 4 − 61
Steering/Lift Circuit Testing − Steering Control
Valve and Steering Cylinder Test:
Unit steering performance will be affected by incorrect
rear tire pressure, binding in the hydraulic steering cylin-
der, extra weight on the vehicle, and/or binding of the
steering fork assembly. Make sure that these conditions
are checked and functioning properly before proceeding
with any steering system hydraulic testing.
1. Make sure hydraulic fluid is at normal operating tem-
perature by operating the machine for approximately 10
minutes.
2. Drive machine slowly in a figure eight on a flat level
surface.
A. There should be no shaking or vibration in the
steering wheel or rear wheel.
B. Steering wheel movements should be followed
immediately by a corresponding rear wheel move-
ment without the steering wheel continuing to turn.
3. Stop unit with the engine running. Turn steering
wheel with small quick movements in both directions.
Let go of the steering wheel after each movement. The
steering control valve should respond to each steering
wheel movement.
4. If either of these performance tests indicate a steer-
ing problem, determine if the steering cylinder is faulty
using the following procedure.
A. Park machine on a level surface with the cutting
units lowered, reel enable/disable switch in the dis-
able position, and the parking brake engaged.
B. With the engine running, turn the steering wheel
to the left (counterclockwise) until the steering cylin-
der rod is fully extended and turn the engine off.
C. Read Precautions for Hydraulic Testing in this
chapter.
D. Remove hydraulic hose from the fitting on the rod
end of the steering cylinder. Plug the end of the hose
removed.
E. With the engine off, continue turning the steering
wheel to the left (counterclockwise) with the steering
cylinder fully extended. Observe the open fitting on
the steering cylinder as the wheel is turned. If hy-
draulic fluid comes out of the fitting while turning the
steering wheel to the left, the steering cylinder has in-
ternal leakage and must be repaired or replaced.
F. Remove plug from the hydraulic hose and recon-
nect the hose.
5. If steering problem exists and steering cylinder
passed test, perform the Gear Pump (P2) Flow Test and
Circuit Relief Valve Pressure Test (see specific test pro-
cedures in this chapter) to make sure the steering con-
trol valve and cylinder are receiving adequate fluid flow
and pressure. Based on the results of these tests, repair
or replace steering control valve as necessary (see
Steering Control Valve and Steering Control Valve Ser-
vice in this chapter).
Hydraulic
System