Originally Posted by Mike Oxbigger
I thought your supposed to check the charge level on the low side ie. the larger of the pipes. thats what my recharge kit said to do at least. any idea on what somebody would charge to check out the a/c system?
Depends on what kinda of refrigerant you have in there. More than likely you have a R-134a since you said you picked it up at the auto store. To check the charge level, ACCURATELY, you're really only limited to evacuating the system and seeing how much you pull out, vaccuming (this does no harm and in fact benefits you're system to remove moisture and air), and recharging. I don't get those aftermarket gauges...all they can tell you is how your pressure is, not how much refrigerant is in the system, even then low side pressures are usually in a TXV system somewhere in the vicinity of 25-44 psi, when working, and I think it is something like 70 psi, when both sides equalize and are not operating. Those kits are great for the backyard mechanic who is going to sell his ride...but for someone who is going to keep his/her ride, it better to do it the right way, especially since those kits (if you look on the bottle) will contain sealer and dye (which is really not good for the system, well the sealer at least isn't). In fact, we have to check to see if a system has sealer, if it does, we can't do squat to the system and it must be taken somewhere where someone has a scavenger unit to evacuate the system of the refrigerant.
I believe charging with a proper machine is done through the high side, I'd have to look on my machine to be sure (it normal has a valve switch that you open to charge an a/c on one of the sides). Obviously those aftermarket kits maybe different, and I would say refer to the instructions for it.
I have seen shops charge $39-$79 for A/C diagnostics, considering that this is supposed to be an hour worth of labor. If he adds refrigerant to the system, they will charge you for that. I don't know what it is in the current market, but where I am training at, they give it to us at cost for $0.50 an oz. and R-12 is $3.00 an oz, and believe me that is cheap. Make sure they also add the same amount of oil that they pull out during evacuating, I believe the Honda uses Nippondenso-8 or 9 oil, or more commonly known as PAG oil.