Tools for A/C work

[Eric Sanborn]

On 6/28/05, Kunz, Bob <bob.kunz at hp.com> wrote:
> Actually, you'll want to find the leak, it's the best way. It might be
> easier to fix a leak, and buy your own R-12 (you'll need to get an EPA
> certification but it's easy and cheap).
> 

I agree that this is the best way.  Since everyone's mileage varies I
tell you how I have done it.  I use a $9 venturi vacuum pump.  I buy
R-134a by the case at Advance and they typically give me 20% off if I
ask nice.  I use a standard cheap guage set.  Whenever possible I tear
the whole system apart and run the flush fluid through.  That gets
most of the R-12 oils out. I put the required amount of oil into each
component as I put the system back together with new R-134a rated
o-rings. Then pull a vacuum for 45 minutes and then close the valves
and see if it holds.  Last I charge with R-134a to 80% of the original
charge by weight.  I should, but I don't get too fancy on the exact
weight.  I typically only get within half a can or so.

If you have a leak in lines this will do you no good.  If it is a bad
compressor you are already planning to swap that is a likely culprit. 
Always use a new rec/dryer if the system has been open more than a day
in the summer.

Now of course YMMV, but I have done this on 2 Suburbans and a Honda
with terrific success.  All were originally R-12 systems and all work
great now with R-134a. The Honda is the most marginal when not moving,
but I attribute this to insufficient fans.  The first Suburban I did
it on delivered 34°F air regardless of outside temperature after about
10 minutes of driving.  Up to about 80°F outside you had to temper it
with some heat to be comfortable on longer drives.

Good luck!



-- 

Eric Sanborn
http://sofadog.net/4ktq/