Hardee by EVH
Maintenance
DB4048 & DB4060 HYDRAULIC ROTARY CUTTE
14 4/3/09
Replacement
9 Remove cotter pin and castle nut from blade
holder shaft.
9 With an assistant, carefully remove the blade
holder.
9 Then position the new blade holder in place.
9 Replace the castle nut and cotter pin.
See parts breakdown drawing on page 7 for
reference.
Checking the Cutter Head Relief Valve
The DB-4048 & DB-4060 are equipped with a cutter-
head relief valve that comes pre-set from the factory.
This valve is attached to the top of the pump (Item 37
on 22700 and 22721) before checking the pressure on
the valve, make certain that a clean filter is installed
and that the reservoir contains the correct amount of
hydraulic oil.
The procedure to check the pressure on the cutter-
head relief is as follows:
9 Start the tractor and with the tractor in park, place
the cutter-head on the ground. Engage the tractor
PTO to power the cutter-head and increase
engine speed until 540 PTO RPM is reached.
Allow the mower to run at this speed for 3 to 5
minutes.
9 Disengage the PTO and stop tractor engine.
9 Remove the pump pressure line. Install a 3000 or
5000 psi pressure gauge into the 12-M-JIC outlet.
The gauge should block off the pump outlet
downstream of the relief valve. Place the loose
pressure line in a clean container to catch any
spillage.
Caution
Be sure all fittings are tight before proceeding!
9 Start the tractor engine and increase engine
speed to 1200 ENGINE RPM. Engage tractor
PTO and immediately observe the pressure
reading and disengage tractor PTO. (If pressure
reads 2500 psi or less, you may proceed.)
9 Increase tractor engine speed to 540 PTO RPM.
Engage tractor PTO and immediately observe the
pressure reading and disengage tractor PTO.
The correct pressure setting is 2500 psi. If the
reading is less than 2000 or more the 2500, contact
your local Hardee dealer for assistance.
Caution
Never let the unit operate in the capped position for
over 5 seconds. A reading can be obtained accurately
in this amount of time.
9 Now you can remove the cap and gauge, and re-
install the pressure line.
CAUTION
Never vary from the 2500-psi cutterhead pressure.
Failure to comply with this specification will cause
severe hydraulic heat, loss of power and damage to
components.
DANGER
Exceeding 2500 psi will cause premature hose failure
(rupture), and possible bodily injury or property
damage.
WARNING
Hydraulic cylinder lines are under high pressure. Make
sure that the deck rests firmly in the ground, all
hydraulic pressure is relieved, and tractor engine is off
before removing hydraulic lines.
To Next Page
Loading...
Need help?
General
