Operating instructions

Tractor Hydraulic Requirements
396-001160 SERVICEBULLETIN
HydraulicValvePush/PullBypassValveOpensorCloses
Description: The red handled push/pull valve on the SureFire PWM hydraulic valve can open or close on its
own. This is due to hydraulic back pressure from the return line overcoming the spring in the valve. The valve
can rotate slightly and move from open to close, or close to open. This can cause poor operation of the total
hydraulic system.
Solution: The red handled push/pull valve can be removed and replaced with one of two plugs. A standard
#10 Male Boss Plug can be put in place of the red handled valve to create an open centered valve. A cavity
plug can be put in place of the red handled valve to create a closed center valve.
Whenshouldvalveberanopencenter?
(equivalent to handle up)
1. When running in series with another hydraulic
motor, such as a planter fan motor. The SureFire
valve must allow all oil going through the fan to
pass through it. The SureFire valve will be ‘open
center’ and divert the necessary oil to the SureFire
hydraulic motor.
2. When running in series with two SureFire valve/
motor combinations. This might happen in the
case of two seed drives or two pumps. Each valve
needs to let excess oil pass through so the second
valve has plenty of oil to accomplish it’s necessary
task.
Whenshouldvalveberanclosedcenter?
(equivalent to handle down)
1. When running this valve by itself from a tractor
hydraulic remote. By running closed center, the
SureFire valve will use the minimum amount of
oil and cause the least oil circulation and heating.
This leaves the most oil for other hydraulic
functions.
2. When running off power beyond hydraulic ports,
the valve must be closed.
Remove red handled
push/pull valve to
replace with plug.
Install this #10 MB plug to run
open center. Valve will allow all
oil to pass through it, then divert
necessary oil to the hydraulic
motor
Install this cavity plug to run
closed center. Valve will only
allow oil motor needs to pass
through.
CrustBuster
DrillMaster Quick Start Guide
346-001150 Pg 30 Revised 11/2010
The hydraulic drive motors require a maximum of 7 gallon per minute of hydraulic oil at a
maximum pressure of 1500 psi. Average oil requirement is usually less then 5 gallon per
minute.
With minor modication the drive PWM valve will function with a tractor equipped with a
closed or open center hydraulic system. Contact your tractor dealer to determine which
hydraulic system your tractor may have. Most recently manufactured tractors are equipped
with a closed center hydraulic system. The PWM valve is shipped with the closed center
cavity plug installed.
Tractors with open center system or: Tractors with closed center system or: