Specifications

Triumph Sickle Bar (Archive Book) 10/02

Parts Section -156

VALVE(s):

The major cause of valve malfunction is dirty oil or foreign material causing the valve spools to be

scored or seals to fail. If repairs are required remove the valve from the system and thoroughly clean

all parts before reassembly. Replacement parts and service kits are available. The valve body and

spools are match fitted and are not interchangeable or adjustable. Check the valve lever linkage for

free movement to allow the detents to locate without binding.

PRESSURE RELIEF VALVE:

The pressure relief valve for the entire hydraulic system is built into the control valve. The relief

pressure is factory set at 1700 PSI. (Does not apply to mower operating from John Deere internal

pumps). To adjust the relief pressure, loosen the jam nut and adjust the screw clockwise to increase

pressure, counterclockwise to decrease pressure. The relief pressure can be checked in several

ways:

1. Install a tee and a 0-3000# PSI gauge in the inlet high pressure side of the governor.

2. Raise the mower to the full upright and transport position holding the bar lift control in the raised

position. Read the gauge.

3. Block the knife with a heavy piece of wood between two guards. Then turn on the motor with

the motor control lever. Read the gauge.

Either of these methods forces all the oil to go over the relief valve and at 1200 RPM or higher engine

speed the gauge should read 1700 PSI (or 2250 PSI for John Deere system).

ATTENTION! Never operate the mower with incorrect relief valve settings. A low setting will cause

poor performance and high oil temperatures. A high setting can result in damage to

pitman, knives, hoses, etc.