Thermo King 919180, Manual

Page: 110 / 148

Refrigeration Service Operations
110
Installation
NOTE: Three-way valve kit is used to repair
three-way valves (see Tool Catalog).
After cleaning and inspecting all parts, reassemble
the valve. Clean solder off the condenser line and
condenser head with sandpaper and tubing brush.
1. Install the screen into the bottom cap.
2. Install new stem into the center section.
3. Install new gaskets on both sides of the valve
body. Dip gaskets in compressor oil (use same
type of oil that is used in the system) before
installing.
4. Install a new o-ring on the piston, then place
the Teflon seal over the o-ring.
5. Install the piston on the stem and attach with
spring clip.
NOTE: The Teflon seal will stretch when it is
installed. To prevent this from becoming
permanent (and possibly malfunction), the
top cap must be installed immediately.
6. Install the spring and top cap.
7. Line up the passageways in the cap and body.
Failure to line up the holes will result in
improper operation of the valve.
8. Install bolts and tighten in rotating sequence.
9. Solder condenser line to the condenser inlet.
10. Install pilot solenoid line and pressurize
system with refrigerant to check for leaks.
11. If there are no leaks, evacuate the system and
recharge with refrigerant.
12. Run the unit to check for proper three-way
valve operation.
R-404A
The refrigeration industry has introduced a new
refrigerant called R-404A. This refrigeration is
classified as a Hydro-fluorocarbon (HFC) because
it contains hydrogen fluorine and carbon. It does
not contain chlorine.
The capacities of these new refrigerants are
similar for box temperatures above 0 F (-18 C). At
temperatures below 0 F (-18 C), HFC refrigerant
capacities are slightly less than CFC refrigerants.
Unit Identification
Units charged with R-404A are identified by the
following methods:
1. HFC-404A will be stamped on the unit’s serial
plate.
2. “HFC” may be incorporated in the model
designation on the sides of the unit.
3. Decals will be applied to unit as shown below:
Figure 68: R404A Decal
Availability
Refrigerant 404A is available from wholesalers.
The price will depend upon the quantity
purchased. Thirty (30), 50 and 125 containers are
available.
Leak Detection
Leaks can be detected by a Halogen leak detector
such as the G.E. H10G or portable leak detector
(see Tool Catalog). See Truck and Trailer Service
Bulletin T&T 048 for additional details.