(5) When proper tension is achieved secure
mounting bolts, nuts and align pulleys while
(6) Rotate belt by hand to check for unusual
drag or binding and reinstall back access panel,
securing with mounting screws.
4-18. Oil Pump Assembly (Refer to Fig C-11)
a. Periodically it is advisable to remove the oil
pump filter screen and clean with solvent to remove
all foreign matter.
b. To remove oil pump filter screen, proceed as
(1) Remove the eight cover mounting bolts and
separate cover from body, exposing filter screen.
(2) Remove filter screen and clean.
(3) Reinstall screen and secure cover with
eight locating bolts.
4-19. Burner Adjustment and Cleaning (Refer to
a. The burner plate assembly may be removed by
disconnecting the two spark electrode leads, intake
copper tube lines, flame scanner and three wing
b. Gently lower assembly from blower duct
being careful not to drop or bump spark electrodes.
c. Wipe off complete assembly and remove the
two burner nozzles for disassembly and cleaning of
d. Reinstall nozzles and proceed to inspect spark
electrodes for cracks, pits or signs of arcing to
e. If electrode replacement is not required adjust
to specifications as referenced and reinstall burner
f. Prior to connecting flame scanner wipe off
lens with clean rag and secure finger tight only.
4-20. Fuel Nozzles-Removal and Cleaning
(Refer to Fig C-16)
a. The burner assembly consists of two fuel
nozzles, each nozzle consisting of a filter screen
stem, spinner core and body with orifice.
b. To remove and clean fuel nozzles proceed as
(1) Fuel nozzles should be removed and
cleaned every three or four months or after each 250
hours of unit operation. If fuel is contaminated,
greater frequency may be required.
(2) Remove burner assembly, see paragraph 4-
19 and remove nozzles utilizing two wrenches.
(3) Remove nozzle screen and spinner core and
clean in solvent, blowing down with air pressure.
4-21. Coil Inlet Assembly (Refer to Fig C-14)
The coil inlet plumbing assembly should be
inspected for leaks, loose fittings and connections.
Should inspection reveal any problems, repair per
instructions in paragraph 4-10, loose or leaking
4-22. Coil Outlet Assembly (Refer to Fig C-17)
a. The cod outlet plumbing assembly should be
inspected for leaks, loose fittings and connectors
and repaired per paragraph 4-10.
b. A leaking discharge or soap tank fill valve
may be repaired by loosening valve bonnet and
removing stem assembly.
c. Valve seat, teflon disk, may be turned over to
utilize the new surface.
d. Leaks around the stem packing gland cap may
be corrected by tightening the packing gland nut
when the valve is in a partially open position.
4-23. Preheat Coil Assembly (Refer to Fig C-18)
a. Inspect preheat coil assembly for excessive
corrosion on support straps.
b. Clean surface and repaint, if necessary.
4-24. Generating Coil (Inner) (Refer to Fig C-18)
a. Inspect generating coil (inner) for leaks,
broken or cracked welds and any excessive
vibration. Should inspection reveal any problems
use standard welding procedures for repair.
b. Inspect coil for excessive soot buildup or
restrictions which may prevent normal venting of
combustion chamber. When the findings are
confirmed or questionable, it is advisable to request
assistance from the next higher level of maintenance
to further determine method of corrections.
4-25. Draining Soap Tank (Refer to Fig C-31)
Soap tank draining is accomplished by opening
drain valve and flushing hardened soap deposits
which may have accumulated on tank bottom. Soap
tank stir and fill valve and soap control valve should
be closed so deposits do not enter plumbing system.
4-26. Flame Safeguard Control (Refer to Figs
4-1 and 4-2)
a. To aid in troubleshooting the flame safeguard
control, the following functional description is
(1) When the main disconnect switch is closed,
220V to 110V stepdown transformer is powered
providing 110V AC to the control circuitry.
(2) Power from the X1 terminal of the
transformer secondary flows through circuit No. 1,