Service Bulletin

Ref: 08-21 Copyright, 2003. The Toro Company
Customer Service Bulletin
Commercial Business Group
Groundsmaster
®
4500/4700-D Date: October 22, 2003
Model/Serial Range: Model Number: Serial Numbers:
30856 220000101-230000782
30868 220000101-230000725
Subject: Loud Hydraulic Noise when Lifting Decks
Some units may emit a loud high pitch hydraulic noise when the decks are being raised
or when it goes over lift relief. The decks will still lift but the noise can be loud enough
to cause operator concern. The noise will seem to be coming from under the operators
seat area, and is caused by the Triple Pump Assembly Proportional Valve vibrating
rapidly.
If this noise develops, an improved Proportional Valve in now available. This improved
valve has a design that will eliminate the loud hydraulic noise when lifting or going over
the lift relief.
Contact you local authorized Toro Commercial Products Distributor for additional
information and assistance regarding this issue.