Charging A/C?

I have a '94 Accord, which is a 134a system. In 10 years, no
refrigerant has been added. I have no numbers to back it up, but my
sense is that it doesn't cool as well as it used to, which may be
partly due to the fact that the compressor cycles more than it used
to. Actually, I don't remember it cycling at all in hot weather
when it was new. Anyway, my strong suspicion is that it needs to be
charged a bit after 10 years - but, if it matters, only 45k miles.

A friend suggested we mount his digital thermometer in front of the
output air stream, and slowly add refrigerant until the temperature
stops falling. He said he did that on his Honda, but it was an
older model using freon-12.

Does this make any sense, or does the difference between freon-12
and 134a systems make it not work for some reason? Or, you know,
should I just add one can and see what happens?

(I need to do this myself if I can do so without screwing things
up.)

 

if youre going to DIY, at least get the DIY set with the pressure gauges
and find what the proper pressure is supposed to be, and do it at least
*halfway* "right".

i can see the hesitation in taking it somewhere... half the time the
tech will tell you that you need an expensive part that you probably
dont need.

 

As Mike has said, go get the kit from your local auto parts store.
This will at least tell you when you have filled in the amount of
refrigerant that is in the "normal" range. I would also get a A/C
thermostat and run the A/C on high for about 10 minutes and see what
the reading is. The readout should be between 40 and 45 degrees. Add
the refrigerant in little increments at a time and constantly check to
make sure you are not going over the limit. Read all directions on the
bottle and kit to avoid any problems. You should be able to do this
yourself if you are technical.


Good Luck,
Nick

 

This won't help you with the current problem, but it MAY help prevent it in
the future if, indeed, it is low on freon. This is old information, and I'm
not sure it still applies, maybe come auto A/C experts can comment. With
the low mileage after 10 years, it gives me a hint that this may be a cause
of your problem.

You should run your A/C for a few minutes at least 1/month even during the
winter to keep the seals pliable or moist.

I welcome any comments from A/C experts - is this still good advice?

 

always good advice. using the defrost mode on most cars automatically
turns the AC on.

 

it's great advice!! people constantly ask how to defeat the a/c
coming on with the defrost, and i won't tell. it's good to run it, and
it defrosts faster.. i've seen a lot of a/c systems die of
non-usage.
Chip

 

if I were you I would take it somewhere where they use a recovery/recycle
machine. before adding refrigerant to an a/c system, the system needs to be
vacuumed to get rid of any air and moisture. most newer recovery machines
can be programmed to add just the right amount of refrigerant in order not
to cause damage to the compressor. a/c compressors are very expensive.

 

What you describe is evacuating and recharging. If you are just a tad
low on refrigerant after years of use, it is perfectly fine to simply
add a bit of refrigerant.

 

i call my self a sort of expert because i have charged many a friend's honda
accord. i have changed condensers hoses etc i have converted many a vehicle
from r12 to r134a. all you need to do is buy two t hings....a single can of
freon 134a and a charging hose. you can get both these things from straus
discount auto for about 14 bucks for both. you siimply connect the can to
one end and connect the other end to the low side hose connector in y our
car.....turn the lever that punctures the can clockwise then back it out and
let the freon flow from the can to the car. i suggest you let half the can
enter the system then turn the lever clock wise to stop it.. check to see if
its cold enough. if its cold enough stop and take it off , if its not cold
enough keep going til thhe can is empty. if you need to add additional freon
go ahead......
in my opinion those kits arent needed and since you system is already
134a you dont need to buy the kit . dont worry about over charging it just
add half a can at a time until its cold..........sometimes people make
things too complicated.... also you dont need to monitor the pressure with
hoses... i have done this many times.... if you are still worried just keep
looking at the ac's sight glass it should be a kind of milky water color..
when the milky color turns clear that means you have added to much.....you
might also want to used the freon with the oil in it just to keep your
system lubed but since you already have a 134a system i dont think thats
needed.