[ale] [WAY OT] WARNING - diy car ac recharge kits can be dangerous

[Ron Frazier (ALE)]

Hi all,

OK, yes, definitely not Linux related, but I thought you guys might want 
to know this and, well, I'm not active on car forums.

I've learned the hard way that diy ac recharge kits can be dangerous.  
How hard the hard way is has yet to be determined.

So, I traded one car and got another used car last year.  The ac seemed 
to be running intermittently, so I get the handy r134 recharge kit from 
autozone with the built in low pressure gauge so you can tell what 
you're doing.

Instructions say, basically, adjust the pointer on the gauge for the 
outside temperature, connect hose to low side ac port, run compressor, 
squeeze trigger and periodically shake the can.  You should be done when 
gauge is in green zone and air is cold.  So, I watch the gauge and keep 
squeezing the trigger.  It never leaves the green zone.  I keep doing 
this for a while ASSUMING the magic gauge will let me know if there is a 
problem.  After a while, things are stable and the gauge is not varying 
much.  Air is cold, so I disconnect everything and go do the same 
procedure on my wife's car.

Note, the instructions say DO NOT OVERCHARGE!, but the clear implication 
is that you're not overcharging as long as the gauge is in the green.

Fast forward to a couple of days ago, my ac is again intermittent on a 
hot day, so I repeat the procedure.  Same results on the gauge.  But, 
not the same results under the hood.  Now the compressor literally runs 
only for 1 second or so.  A couple of times, when it tries to turn on, I 
hear this grinding noise and see smoke.  Pretty sure that was the clutch 
slipping.  I turn the unit off and take it to my mechanic.

He calls me later and tells me my high side pressure (which is not 
measured by the diy kit) is around 400 PSI and he's surprised that the 
whole system hasn't exploded.  Wow, that was fun to hear.  He's going to 
evacuate and recharge the system and we'll find out if anything has been 
damaged.

So, APPARENTLY YOU CAN OVERCHARGE with a diy kit and you'll never know it.

Try googling diy ac recharge overcharge, and you'll get some interesting 
results.  One forum post says you can only know if you've charged enough 
by weight, not by pressure.

So, now I have to pay $ 100 to evacuate and recharge my car ac.  Then, I 
have to do the same to my wife's car, because I don't know if it's safe 
or not.  Then, if I've damaged something, I have to figure out whether I 
want to pay hundreds more dollars to have a working ac again or just 
sweat it out.  I'm really hoping the system will still work.

If it's that easy to screw the system up and it's that hard to tell if 
you're doing it right, I almost think these products shouldn't be on the 
market.

Hard lesson learned.  It could have been a lot harder.  I guess I could 
have caused an explosion.  Hopefully, the high pressure sensor would 
have just disabled the system before that.

If I have to replace the compressor, drier, and expansion device 
(usually done together), this looks like a good source online.  I've 
never used them, just read the website, but they have a complete kit for 
my car for $ 300.

http://www.discountacparts.com

Like I said, just passing this along.  Maybe my story will save someone 
else some grief.

Sincerely,

Ron


-- 

(PS - If you email me and don't get a quick response, you might want to
call on the phone.  I get about 300 emails per day from alternate energy
mailing lists and such.  I don't always see new email messages very quickly.)

Ron Frazier
770-205-9422 (O)   Leave a message.
linuxdude AT techstarship.com
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