Snap-On Dual 3412 - Installation and Operation; Connecting Hoses and Preparing Unit

2-1
IInnssttaallllaattiioonn
aanndd OOppeerraattiioonn
2
Use information in this chapter to:
• Prepare
DDuuaall 33441122
for initial use,
• Recover vehicle refrigerant,
• Create a vacuum before recharging, and
• Recharge with recycled refrigerant.
Connecting Service Hoses to
DDuuaall 33441122
Use the following procedure to connect service hoses to
DDuuaall
33441122
. Refer to Figure 2-1.
 Do not use
DDuuaall 33441122
or leak detector equipment if
R-12 substitutes are suspected. R-12 refrigerant
substitutes may be flammable.
 Read, understand and follow
SSaaffeettyy IInnffoorrmmaattiioonn
in
the front of this manual.
 Refer to
PPaaggee 11--44
33
33
Confirm refrigerant type in vehicle, and use
appropriate connections on unit.
33
33
Always lubricate rubber gaskets and seals at hose
connections with fresh refrigerant oil before connecting.
33
33
Tighten hose connections finger tight. Use electronic
leak detector to insure connections are leak free.
1. Connect an anti-blowback valve, two found in unit
accessories, to end of each yellow service hose with
hand valve.
2. Attach end of yellow hoses without hand valve to center
port of manifold gauge assemblies.
3. Attach end of yellow hoses with hand valve and anti-
blowback valve to “Recycle” port on side panel.
4. Attach end of blue hoses, without hand valve (R-12), to
low side (left) port of manifold gauge assembly.
5. Attach end of red hoses, without hand valve (R-12), to
high side (right) port of manifold gauge assembly.
6. 134a refrigerant only – connect high (red) and low (blue)
couplers to their respective hoses. Rotate coupler knobs
fully CCW (closed).