Re: bmw-digest V9 #1497

[Scwitzig@xxxxxxx]

Subject: <E30> A/C Expansion valve--thermostat??

2. The cover is for shipping and should be removed; the probe should stay
in the curled in position.

The expansion valves orifice on the liquid line is influenced to be more open 
due to an internal pressure differential on a reservoir of refrigerant in the 
valve. This thermostat  utilizes air temperatures and exiting refrigerant 
pressures as inputs to mechanically balance the flow of refrigerant through 
the orifice and into the evaporator. The cover should be removed, but that is 
all. 
    Take extra time and care when fitting the liquid line to the valve if you 
have replaced the original  R12 valve with the R134a .  I found out that the 
end of the liquid line , the region in front of the o-ring land, may be too 
long.  The internal contour of the #6 liquid inlet of the valve is slightly 
shallower.  The result of which is a poor seal between the hose and valve.  I 
carefully filed the end of the #6 hose fitting down so the assembly fit much 
tighter.  The assembly can be trial fitted with the proper o-ring as a check 
as you file a little at a time.  Mine required removal of about 2.5mm from 
the end of the fitting/hose.  There is a much lower leakage of refrigerant 
this way.

S
84 BMW E30 w 134a
scwitzig@domain.elided

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