Notice – Proheat M125 User Manual
Page 55
4-18
PROHEAT M-SERIES G-II PCM SERVICE MANUAL
Fuel Supply Pump cleaning:
a)
Disconnect all harnesses at the G-II PCM.
b)
Disconnect the fuel supply line.
c)
Loosen and back out the burner head mounting (2) bolts five to six turns
allowing enough room to rotate the burner head 15° counter-clockwise
and remove.
d)
Locate the pressure relief valve cap and remove with a slot screwdriver.
Careful not to lose any of the internal components that may fall out.
e)
Remove the spring from the cavity.
f)
Remove the ball bearing from the cavity.
g)
Inspect and clean all components.
h)
Inspect and clean the cavity. Pay close attention to the center hole in the
cavity for any debris or a damaged edge. The edge of the hole should be
smooth with no nicks, do not use any tool that may damage this edge as
this will cause loss of fuel pressure.
i)
Place ball bearing back in cavity on the center hole.
j)
Place spring back in hole with brass ball guide on top of ball bearing.
k)
Install pressure relief valve cap.
l)
Re-test the Fuel Supply Pump. Start from item 'e' in Test procedure –
Fuel Supply Pump pressure, page 4-17.
If the Fuel Supply Pump pressure tests OK, go to item 'm'.
If the Fuel Supply Pump pressure is still incorrect, go to Fuel Supply
Pump replacement
m) Reassemble the burner head.
n)
Reinstall electrical harnesses and fuel supply line.
o)
Switch the PROHEAT on and operate for at least one complete cycle.
Observe the operation.
Fuel Supply Pump Gear Check/Replacement:
a)
Disconnect all harnesses at the G-II PCM.
b)
Disconnect the fuel supply line.
c)
Loosen and back out the Burner Head mounting (2) bolts five to six turns
allowing enough room to rotate the Burner Head 15° counter-clockwise
and remove.
d)
Remove the Ignition Electrode then the Flame Shield.
e)
Disconnect the Fuel Solenoid Valve from the PCM.
r)
To prevent contamination, clean area around the base of the Fuel
Delivery Block prior to disassembly.
g)
Remove the Fuel Delivery Block by removing the three M6 screws and
three Lock Washers. Be careful not to lose the gears or Idler Shaft.
h)
Inspect the gears, gear seats and shafts for damage. Replace as necessary.
Inspect fuel delivery bock screen for contamination.
i)
re-install the two Gears and Idler Shaft into the Compressor Flange
ensuring the area is clean and free of debris Lubricate both Gears with
diesel fuel prior to installation. Note idler shaft orientation.
j)
Install new Fuel Delivery Block large and small O-rings, Inlet Screen and
Inlet Screen O-ring onto the Fuel Delivery Unit as shown. Ensure to
lubricate all O-rings with diesel fuel prior to installation.
Figure 4-20: Pressure Relief Valve Cap.
PRESSURE RELIEF VALVE CAP
TORQUE = 22 in-lbs ±2 in-lbs
(2.5 Nm ±0.2 Nm)
SPRING
BALL BEARING
BALL GUIDE
NOTICE
All plugs/harnesses must be rein-
stalled into the G-II Proheat Control
Module (G-II PCM) before heater
goes back into service.