Napa COLD POWER 78-1307 Manual De Instrucciones página 7

TROUBLESHOOTING
TROUBLESHOOTING COMPRESSORS
Checking compressor ratios is an
excellent way to check system
performance and possible failures.
Run the vehicle at 1500 RPM and
record both gauge readings then
add 15PSI to your reading.
Example:
35PSI plus 15=50 (low)
235PSI plus 15=250 (high)
250:50=5 to 1 ratio
R-12 acceptable ratios are between
5 to 1 and 6 to 1.
R-134a acceptable ratios are between
6 to 1 and 7 to 1.
If a systems exceeds these ratios, the
compressor may fail to high internal
pressure on the pistons and swash
plates.
Possible causes of high ratios are
refrigerant overcharges and air in the
system. Recover/recharge, vacuum,
and identify source of excess air.
(Use refrigerant identifier to check
equipment, tanks, and system.)
BK 78-1307
78-1307_manual_102406.indd 7
CLUTCH PROBLEM AREAS
BURNED CLUTCH
1. Hub/armature and rotor/pulley
drive faces have oil or grease on
them.
a. Look for shaft seal leak and replace
clutch.
b. Compressor leaking through the
bolt. Repair leak source.
2. Check for missing or improperly
installed snap ring. Repair or replace
the clutch.
3. Field coil snap ring is wrong size.
Measure thickness and refer to parts
manual for correct size. Repair or
replace clutch if damaged. Always
check anti-rotation pin damage.
Retaining ring should be facing away
from the compressor, fully seated
in groove, lug of ring should not be
over the anti-rotation pin, and field
ring tight against the compressor.
4. Check to ensure clutch components
are matched correctly. The straight
coil to straight rotor/pulley and
stepped coil to stepped rotor/pulley.
Repair or replace if they don't match.
REPLACE IN PAIRS.
5. Look for high pressures. Remember,
too much oil will cause slugging and
low oil causes binding. Make sure you
don't have an airflow restriction.
7
10/27/06 8:49:24 AM