Sears 919.18416 - Manual (Page 10)

NOTE
The belt shoul d be centered over the g rooves on the
flywheel and motor pulley.
6. Push the motor back into regular position and
tighten bolts securely. Proper tension is approxi­
mately 1/4" belt deflection measured midway be­
tween the pulley and flywheel when a 3 pound
weight or equivalent finger pressure is applied at
this point. A loose belt will squeal at compressor
start-up.
7. Replace beitguard and screws.
Pulley and Flywheel - Alignment
The compressor flywheel and motor pulley must be
inline (in the same plane) within 1/16" to assure belt
retention within sheave grooves. The motor mounting
holes on the sadd le are skewed to square the motor with
the compressor mounting hole as the belt is tensioned.
To check alignment, disconnect electrical power and
remove the belt guard. Place a straightedge against the
outside of the flywheel and measure the distance from
it to the nearest groove. Alignment is achieved when the
other end of the straightedge is within 1/16" of the
measured dimension at the pulley grooves. Squareness
is achieved when the pulley grooves are an equal
distance from the straightedge on both sides of the
motor shaft.
TROUBLESHOOTING GUIDE
AWARNING
UNIT CYCLES AUTOMATICALLY WHEN POWER IS ON. WHEN DOING MAINTENANCE, YOU MAY BE
EXPOSED TO VOLTAGE SOURCES, COM PRESSED AIRORMOVING PARTS. PERSONAL INJURIES CAN
OCCUR. BEFORE PERFORMING MAINTENANCE OR REPAIR, TURN OFF AND LOCK OUT ELECTRIC
POWER AND BLEED OFF AIR TANK PRESSURE. NEVER OPERATE THE COMPRESSOR WITH THE BELT
GUARD REMOVED.
PROBLEM CAUSE CORRECTION
Excessive tan k pressu re - safety
valve pops off.
Pressure switch does not shut off motor
when compressor reaches "cut-out" pres­
sure.
Pressure switch must be replaced.
Air teaks at fittings or hose. Tube or hose fitti ngs are not tig ht enough. Tighten fittings where air can be heard escaping.
Check fittings under soapy water solution. DO NOT
OVER-TIGHTEN.
Air leaks at check valve. Defective or dirty check valve. Remove and clean or replace check valve. DO NOT
OVER-TIGHTEN.
Air leaks at pressure switch re­
lease valve.
Defective pressure switch release valve. Remove and replace the release valve.
Air leaks at air tank welds. Defective air tank. Air tank must be replaced.
AWARNING
DO NOT DRILL INTO, WELD OR OTHER­
WISE MODIFY AIR TANK. IT WILL BE
WEAKENED.
Air leak from safety valve. Possible defect in safety valve. Operate safety valve manually be pulling on ring. If
valve still leaks, it should be replaced.
1
Restricted check valve. * Remove and clean or replace.
1
Loose pulley.
Tighten pulley set screw.
Low oil level. Maintain prescribed oil level.
Loose flywheel. Tighten screw.
Loose compressor bolts. Check bolts. Tighten as required.
Loose belt. Tighten belt as per instructions under Belt Replace­
ment above.
Carbon build-up. Remove the head and valve plate. Clean the valve
plate and the top of the piston. (Be sure carbon does
not fall into the cylinder.) Reassemble to 25-30 ft.lbs.
using new gasket and torque screws.
10- Eng