76
TK 56433-5-MM-EN
determine how much of the end of the hole is
covered by the piston. If the piston covers more
than three-quarters of the hole replace the end cap.
N
No
otte
e:: When front seating a condenser bypass
check valve DO NOT over-tighten the stem.
Excessive torque will deform the piston and
the deformed piston can increase the hole
blockage.
Seat (Center Section) Orifice Check
There are three 0.033 in. (0.84 mm) holes located in the
three-way valve seat (center section). Only one is used
depending on how the valve is configured.
•
If the hole is too large the valve will be slow to shift
from heat to cool when the condenser pressure is
higher than discharge pressure because gas will
flow to the discharge line instead of behind the
piston.
•
If the hole is too small the valve will be slow to shift
from heat to cool when discharge pressure is
higher than condenser pressure because the flow is
restricted.
D
Do
o n
no
ott e
en
nlla
arrg
ge
e tth
hiiss h
ho
olle
e lla
arrg
ge
err tth
ha
an
n 0
0..0
03
33
3 iin
n.. ((0
0..8
84
4
m
mm
m))..
Whenever you disassemble a three-way valve you
should check that all three of the holes are drilled
cleanly.
Figure 93.
Check Seat Orifice
1.
Number 66 Drill Bit
Assembly/Installation
After cleaning and inspecting all parts, reassemble the
valve as follows:
1.
Install the screen in the bottom cap.
2.
Install the new stem in the bottom cap.
3.
Install new gaskets on both sides of the seat. Oil
the gaskets in compressor oil before installing.
4.
Use the three-way valve seal installation tool P/N
204-1008 to install a new seal on the piston. This
prevents the seal from being stretched and
damaged.
a.
Place the tapered tool over the piston.
b.
Lubricate the seal with refrigeration oil.
c.
Slide the seal onto the tapered tool with the
spring side facing away from the piston.
d.
Use the pipe to hand press the seal onto the
piston.
Figure 94.
Seal Installation with Tool P/N 204-
1008
1.
Press by Hand
4.
Tapered Tool
2.
Pipe
5.
Piston
3.
Seal
5.
Place the piston slot on the stem and secure with
spring clip. The open part of the clip should be on
the opposite side of the piston slot.
6.
Install the spring and end 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 the bolts and tighten in rotating sequence.
Torque to 160 in-lb (18 N•m).
9.
Install the pilot solenoid line and pressurize the
system with refrigerant to check for leaks.
10. If there are no leaks, evacuate the system and
recharge with the proper refrigerant.
11. Run the unit to check for proper three-way valve
operation.
