Checking AC perfrmance

you can't use anything conductive, or any contaminated equipment, due to the high voltage compressor. but i have no idea what i'm talking about.

 

I've heard the oil is special, putting in regular oil will mess it up involving significant dollars to fix. This is something I would leave to the dealership, both due to the risk and for their (hopefully) stringent capture of any of the gas.

 

First and foremost, find a diagnostic flowchart. An A/C tech would check the pressure on the high/low lines to see if it's in spec, but most places will first test with a thermometer sensor in the main vent blowing max cool on a hot day. If the temperature is right, it's working fine. If not, the next check is to see if you are low on refrigerant (all systems leak a trace amount over time), and if you're low, they should also check for evidence of a system leak before attempting to "top off" your charge.

Most auto A/C systems need a check/service/top off every 5 years to remain working at optimal capacity.

 

and in any event, use the proper type of refrigerant indicated by the user's manual.
All refrigerants recharge cans contain the right oil for the refrigerant type.
And also you should have checked the Hi and Low side pressure of the sealed system with the appropriate gauge.

 

That's the bit I've read differently about. Apparently the Prius takes a not unusual refrigerant type, but needs a special oil. Safest for DIY would be to ensure the refrigerant you're adding has no oil. Or even safer, and if there's a leak, better to leave it to the dealership.

There's a current thread here, someone had a third party mechanic charge his system, using refrigerant with oil, and he's looking at a big bill now.

 

you're in pennsylvania, so that'll work for you/

Amazon.com: 3 Cans R-134a DuPont Suva A/C Automotive Refrigerant/Freon R134a (12oz Cans): Automotive

 

Wait, someone sold me stuff from the back of his "1980 something" van in a Walmart parking lot........but he didn't tell me it was refrigerant. 3 days later I woke still parked in the same spot.....

 

You do know that in "eco" the AC is modified for efficiencies? -- so it does not work as well. I only ask because we had this issue -- one family member always complained about the AC .. we did tell them not to use the "eco" in extremely hot weather ...... but they forgot

I never use "eco"

 

This is good to know. Now I know why it seems to run cooler out the "eco" mode.

 

Use the site glass to check refrigerant levels that why it's there. Turn air on high let it run 3 min look in site glass should be clear and free of bubbles. If you have bubbles get out your gauges. Air temp at vent depends on ambient air temperature outside if the system is working I would think driving g down the road air temp should be in the mid 40 to 50 degrees Fahrenheit.

 

Consider yourself fortunate to have gone this long without having to recharge the A/C system. I have a digital meat thermometer I stick in my cars A/C vents a couple times a year to check on A/C performance. When the system is operating properly I get a temperature reading in the upper 30's.

 

With all the Honda Shop Manuals I've had in the past, they would say the optimum is to see a few bubbles. If you're not seeing any it might be overcharged. In my experience, I'd see occasional fine bubbles, then a swirl of bubbles, just as the compressor shuts down.

Here's an excerpt for Repair Manual, the AC section. I haven't really read through, don't claim to understand, but it might be helpful.

 

The Prius A/C uses a "subcooling" condenser design: it removes enough heat to condense the vapor to liquid and then further cools it somewhat below the transition temperature. That's why a normal Prius refrigerant charge is to add until there are no bubbles, and then about 100 grams more, which means in normal conditions, you don't expect to see bubbles while the compressor is running.

It is normal to see a swirl of bubbles as the compressor shuts down.

All of the specified conditions (temp. setting, doors open, etc.) matter for making these observations, and as the manual says, if the interior temperature is higher than 35°C / 95°F then some bubbles would not be surprising.

-Chap

 

Have to admit I've never watched the sight glass on our Prius. It's physiologically impossible for me to run the car and let it sit, lol.

 

I bought this last week, it's currently out of stock but should come back soon enough. R 134a R134 A C Pro Hybrid Vehicles Refrigerant | eBay

 

"Bubbles Seen: Insufficient Refrigerant"
"No Bubbles Seen: Insufficient Refrigerant"

Hey Mendel, I think you have insufficient refrigerant. Ha ha. (It explains later that you should have no bubbles until you turn off the AC)

 

As I mentioned, this was Honda sight glass behavior. I've never looked at the Prius sightglass while the car's running. Kinda like Stephen King and his basement...

 

• Compatible and safe for all hybrid vehicle A/C systems

• Improves dielectric performance of older electrically-powered systems

• Recharges lost R134a refrigerant and safely seals minor leaks

• Restores lost oil and boosts cooling system

• For use on all belt-driven, electric, electric and mechanical/electrical combination A/C compressors

• obviously it has some sealant in it, which is not much appreciated by ac shops/
  how would it 'improve' the dielectric performance?
  the type of oil is not specified/
• 
  so I don't know, but I would just go with plain r134a....