Bruce Chang wrote:
> > wrote in message
> ups.com...
>
>>This is a 1990 Geo Metro. This car was previously converted to R134a.
>>Recently I replaced the compressor and dryer. I did everything by the
>>book. I flushed the system with isopropyl alcohol, replaced o-rings,
>>evacuated, oiled it and held a vacuum for several hours. There were no
>>leaks. I even purged it again with dry N2 and evacuated again.
>>
>>Book calls for 1.1 lb of refrigirent (this was for R-12, so I was ready
>>to use only 1 lb of R134a). After putting in 1 lb of R134a, the
>>pressure did not reach the specified values (200/25 psi on the high/low
>>sides). I added some extra refrigirent, and then some more. The
>>pressure was still low. I ended up putting in twice the required amount
>>of refrigirent. But the pressure was still only 125/25 psi. I do not
>>hear or see any obvious signs leaks. Even if there were a leak,
>>wouldn't the pressure initially go up and then slowly come down? Where
>>is all the extra refrigerent going? The air is blowing a little cool,
>>but nowhere near where it should be. The high side tubes are hot, which
>>is a good sign. The compressor is turning over fine, and there are not
>>funny sounds. I am at a loss what to try next.
>>
>>Any suggestions are appreciated.
>>
>
>
> Sounds like your compressor isn't any good. Is the needle shaking or does
> it hold steady? Overcharging the system would only make matters worse. Did
> you happen to manually turn the compressor hub before letting the clutch
> engage? As far as I understood, the amount of R134a compared to R12 should
> be less. Something like 80% was it? Putting in 1 lb R134a compared to 1.1
> lbs R12 is only 90%.
>
>
Could be a leak, too.
THAT much 134a must be going somewhere.

wws