K 2500 Truck 4WD V8-379 6.2L DSL VIN C FI (1989)
thread locking compound, such as Loctite(R) 242, should be used on each bolt of the saddle clamp to prevent the threads from loosening.
Some vehicles produced during the second half of the 1993 model year will already have a factory installed HPCOS. Check the back of the compressor
for this switch. If present, the above switch will not have to be added.
5.
Evacuate the System, and Recharge with PAG or V5 Retrofit Oil and R-134a
Newly designed low profile quick connect couplers for the ACR4, J 39500-20A and J 39500-24A, have been released. These should be installed
before proceeding with the evacuation. See Step 3, and Figure 3.
a.
Connect the R-134a cart (ACR4) to the system. Open the coupler valves on the hoses so that the pressures can be read on the gauges. On the
cart, open the HIGH SIDE VALVE ONLY. DO NOT OPEN THE LOW SIDE VALVE! Program the cart for a 15 minute evacuation.
Important:
If the vehicle has been at outside temperatures of less than 50° F (10° C), or at high altitudes (above 3000 ft), use a 30 minute evacuation
to insure complete removal of the R-12.
If the vacuum pump will not start and a "H-P" reading is indicated on the ACR4 display, loosen the fitting at the high side line
connection to the ACR4 to relieve pressure in the line. Tighten the fitting after pressure has been relieved. DO NOT USE THE
RECOVERY MODE TO RELIEVE LINE PRESSURE.
b.
Start the evacuation. For a proper evacuation, the cart must pull down to 28-29 in. Hg. at sea level (reduce by 1 in. for each 1000 ft above
sea level). Check the low side gauge for proper vacuum level, to make sure the new fittings are operating properly.
While the evacuation is being done, the Retrofit label can be filled out and installed (see Step 6).
Important:
If the compressor was replaced at the same time as this retrofit, and the new compressor was shipped with the correct amount of PAG oil
already in it, DO NOT add any additional oil to the system! Go to Step D. If an "oil-less" compressor was installed, add oil in Step C.
A new retrofit oil for use with V5 compressor vehicles has been released. This oil will be used ONLY for retrofitted vehicles in which
the original V5 compressor is retained. IT WILL NOT BE USED IF A COMPRESSOR IS REPLACED AT THE TIME OF THE
RETROFIT. Failure to use this oil may significantly shorten the useful life of the compressor.
Important:
If the V5 Retrofit oil is not available from GMSPO, the compressor MUST BE REPLACED!
To summarize the correct retrofit oil usage:
^
Compressor replaced during retrofit
-
NO OIL ADDED if new compressor shipped with oil
-
8 oz. of PAG oil (9 oz of PAG oil with V5 compressor) added if compressor shipped without oil ("oil-less" design)
