A/C Chil-rific

[amalventano at sc.rr.com (Allyn)]

Brian,

> 1) Remove all R-12 and flush the system (both condensor and evaporator, 
> don't flush the compressor it can damage the valves)

what exactly do you put through the system to flush it?

> 2) Replace the Expansion Valve

we have that expensive regulated big honkin expansion valve, dont we?

> 3) Replace orings at all the joints

is there a chart somewhere of what sizes we need?

> 5) Put in R134a ester based oil that will work with the old R12 and oil 
> 4.5 to 6 oz(PAG oil should only be used on systems were the compressor has 
> been replaced and the system been flushed). I usually go 6 oz, it will be 
> sucked out of the can since the system has a vacuum drawn on it.

ok, this one has always confused me. if there was oil in the compressor 
beforehand, isnt that oil still in there? how do you 'restart' the system 
(as in - totally empty), so you know that you have _only_ 6 oz of oil in 
that conpressor? in my case my system was r12, then converted to r134a, now 
i want to redo it, so dont i have like a crap-ton of oil in the system by 
now?

> 6) Now put in the first can of R134a (I like Dupont Suva with UV dye)

where do you get this super-badass dupont stuff? all i can find is the 
cheezy stuff that comes in the wal-mart 134a conversion kits (each can has 2 
oz of oil mixed in, so you end up with 6 oz after 3 cans i suppose).

> 8) This is where you start to watch the head pressures, low side should 
> not exceed 40psi and high side needs to be below 225. These pressures will 
> be indicative of how well the system was cleaned, the more gummy the 
> system from old the higher the value. My system runs 15psi on the low side 
> and 160psi on the high side.

hmm, from this page:
http://www.careersnet.org/automotive/PHS/ppt's/Heat&AC/operating/acdiag.ppt 
(slide 8)
it seems that in 90F weather you should have more like 30 / 205 for low / 
high, or is that page incorrect?

> Does this help.

well, it does so far, just gotta work out those details so i know what the 
heck im doing...
thx for assist thus far.
Al