HEATER AND AIR CONDITIONING 1A-16
COMPRESSOR OIL Special re frig e ratio n lubricant should be used in the system . This oil is as fre e from m oisture and con tam inants as it is possible to attain by human p ro c esses. This condition should be p re se rv e d by im m ediately cap ping the bottle when not in use. See "A ir Conditioning System C apacities" for the total system oil capacity. Due to the porosity of the re frig e ran t hoses and con nections, the system re frig e ra n t level will show a definite drop after a period of tim e. Since the co m p resso r oil is c a rrie d throughout the en tire system mixed with the
re frig e ra n t, a low re frig e ran t level will cause a danger ous lack of lubrication. T herefore the refrig eran t charge in the system has a definite tie -in with the amount of oil found in the com pressor and an insufficient charge may eventually lead to an oil build-up in the evaporator.
COMPRESSOR SERIAL NUMBER The com pressor se ria l number is located on the se ria l num ber plate on top of the com pressor. The se ria l num b e r consists of a s e rie s of num bers and le tte rs. This s e ria l number should be referenced on all form s and correspondence related to the servicing of this p art.
INSPECTION AND PERIODIC SERVICE PRE-DELIVERY INSPECTION
7. Check the system controls for pro p er operation.
1. Check that engine exhaust is suitably ventilated. 2. Check the b elt fo r p ro p er tension. 3. With controls positioned for operation of the system , operate the unit for ten m inutes at approxim ately 2000 rpm . O bserve the clutch pulley bolt to see that the co m p resso r is operating at the sam e speed as the clutch pulley. Any speed variation indicates clutch slippage. 4. Before turning off the engine, check the sight glass to see that the unit has a sufficient R efrigerant charge. The g lass should be c le a r, although during m ilder w eather it may show tra c e s of bubbles. Foam in the flow indicates a low charge. No liquid visible and no tem p eratu re differential between co m pressor inlet and outlet lines, indicates no charge. 5. Check re frig e ran t hose connections: "O" ring Connections - Check torque of fittings as charted la te r in this section under "R efrigerant Line Connections;" retorque if required. Leak te st the com plete system . Hose Clamp Connections - If clamp screw torque is le s s than 10 in. lb., retighten to 20-25 in. lbs. Do not tighten to new hose specifications o r hose leakage may occur. Leak te s t the complete system . 6. If th ere is evidence of an oil leak, check the com p re s s o r to see that the oil charge is satisfactory. NOTE: A slight amount of oil leakage at the co m p resso r front seal is considered norm al.
6000 MILE INSPECTION 1. Check unit for any indication of a re frig e ra n t leak. 2. If there is an indication of an oil leak, check the com pressor for p roper oil charge. NOTE: A slight amount of oil leakage at the co m pressor front seal is considered norm al.
3. Check sight glass for p roper charge of R efriger ant-12. 4. Tighten the com pressor brace and support bolts and check the belt tension. 5. Check re frig e ran t hose connections as in Step 5 of " P re -D e liv e ry Inspection.”
PERIODIC SERVICE • Inspect condenser reg u larly to be sure that the fins are not plugged with leaves o r other foreign m aterial. • Check evaporator drain tubes regularly for d irt or restrictio n s. • At least once a y ear, check the system for p roper re frig e ran t charge and the flexible hoses for b r ittle n ess, w ear or leaks. • Every 6000 m iles check sight glass for low re frig eran t level. • Check belt tension regularly.
EVACUATING AND CHARGING PROCEDURES AIR CONDITIONING SYSTEM CAPACITY R efrigerant Charge
Oil Charge
Four-Season System
3 lbs. 4 oz.
10 oz. 525 V iscosity
Roof-Mounted
5 lbs. 8 oz.
13 oz. 525 V iscosity
GM Chevrolet
3 lbs. 4 oz.
10 oz. 525 V iscosity
INSTALLING CHARGING STATION 1. High and low p re ssu re gauge line fittings a re p ro vided in the a ir conditioning system for attaching the Charging Station. Four-Season and Roof Mounted System s—The low p re ssu re fitting is located on the POA valve. The high p re ssu re fitting is located on the m uffler (fig. 25).
10-30 CHEVROLET TRUCK SERVICE MANUAL
