54
TK 56430-18-IP-EN
O-Rings
All Tube-O and ORS refrigerant fittings require matching O-Rings to seal the system. Improperly installed, pinched or
missing O-Rings is a common cause of refrigeration leaks.
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ntt:: All vehicle powered truck units require EPDM O-Rings. NO OTHER O-RINGS ARE ACCEPTABLE.
•
O-Rings should be inspected for damage or flaws prior to installation and never be reused.
•
Always lubricate the O-Rings with POE refrigerant oil and install correctly into cavity before tightening fittings. Refer
to (
“Tightening Refrigeration Hose Fittings,” p. 54
).
•
The correct replacement O-Rings are available from your Thermo King dealer.
Table 7.
Replacement Thermo King O-Rings by fitting size.
Fitting Size
Thermo King O-
Ring Part Number
#4
335679
#6
335209
#8
335680
#10
335682
#12
335683
#16
334997
Tightening Refrigeration Hose Fittings
A common cause of refrigeration leaks is caused by over tightening the fittings. Always use two wrenches while
tightening refrigeration hose fittings or damage to the components can occur.
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1. Over tightening refrigeration fittings will cause damage to the fittings and O-Rings resulting in a
refrigeration leak.
2. Always apply refrigeration oil to the threads and friction surfaces of the fittings prior to torquing.
Fitting Size
Torque Specifications
#4 Flare
11-12 lb-ft (15-16 N•m)
#4 ORS
10-12 lb-ft (13.5 -16 N•m)
#6 ORS
11-13 lb-ft (15-17 N•m)
#8 ORS
15-20 lb-ft (20-27 N•m)
#10 ORS
21-27 lb-ft (28-37 N•m)
#12 ORS
28-33 lb-ft (38-45 N•m)
Figure 49.
Always use two wrenches while tightening refrigeration hose fittings or damage to the components can
occur.
