AC Temp Chart

I am looking for a service manual chart for my 2007 double cab. The chart that shows ambient temp, humidity, temp at vent, and line pressures.

I have seen these charts for other vehicles floating around the web but haven't been about to track one down for our Tundras.

 

Any P/T chart for the refrigerant should basically show you the same info. It is less vehicle specific, and has more to do with the type of refrigerant. Did you open your system for some reason?

 

Yeah AC hans't been working right since I bought the truck 3 months ago. Compressor was making tons of noise and inconsistent cooling power. Bought a new Denso compressor and swapped out. Seems the Previous Owner put in a non-OEM compressor and there wans't a drop of oil it. Pulled a vacuum and loaded up with approx. 22oz of 134a but I think I might have lost a few ounces along the way changing cans and purging lines.

 

Compressor noise is bad. Did you use a gauge set? Check condenser for chunks of metal inside? Replace dryer filter? Follow the proper sequence of turning valves when adding refrigerant? If any air got into the system at all you’d have to start over with vaccuum pump. Not a bad idea to leak test with a gauge that reads in microns.


Proper AC evac/charging is way more finicky than most people give credit.

 

I just took the old compressor and put in a new one. I had bought a new dryer but didn't have the correct screw to open up the housing, so skipped it. Yes, we used a vacuum pump for 45min, purged the air from the lines and added just under 24 ounces. Shop wanted $1k to do this work so I figured I'd give it a shot for $350 in parts and 4 hours in my own labor.

New compressor seems like it fixed the issue. No more noise, normal clutch operation, and is blowing fairly cold. Measured 40deg today (65deg ambient temp).

Just looking for that chart to figure make sure I'm getting the right temperatures on hotter days coming up. If it seems too far off the plan is to get the right tools to change the dryer, open that up and swap it, then go to a shop to have it professionally leak tested and filled.

 

65F is warm, should be closer to 45F discharge. My guess is you have air in system or a leak.

Replacing dryer filter also really isn't optional. You need a fresh one any time you open the system.

Leak testing and proper fill can be done DIY with the following tools;

CPS VG200 digital vacrometer
Decent set of r134 gauges
Vaccuum pump

You should always pull good vaccuum then valve off the pump and let it set a couple hours minimum with a micron gauge (vacrometer) to see if you have leaks. It's $150 well spent for a tool. Can save you a ton of money in refrigerant lost due to leaks.

Obviously, head to a shop if you need to evacuate refrigerant. Letting it piss into the atmosphere is not cool.

Otherwise, check out youtube tutorials. How and when you open valves during process, purging lines before charging, etc. is all very important to keeping air out of the system.

 

blowing 40 out the vent when the ambient (outside) temp is 65.

I'm guessing the chart in question does not exist.

 

Bumping for visibility

 

I ended up finding a generic R134a pressure chart and checking the pressures HI/LOW with that. I added an additional 6 ounces. I guess I lost this 6oz somewhere along the line bleeding lines and connecting/disconnecting the pressure gage.

We are due for some 90deg days here in Tampa this week I will update.

 

If you aren't getting 30-35F drop across the coil, there is a problem. Measuring output temp vs ambient is not relevant. You need to measure the air at the AC intake vs the vent and subtract.

To reiterate my earlier comment, regardless of charge amount, if you got any air or moisture (from humid air) into the system it will never work right. This is why you have to replace the drier filter any time you open it and be very careful not to allow air in between pulling vacuum and charging. Moisture will also wear out your compressor prematurely.

You might be fine for a while, but I would at least check the temperature drop across the coil. I was an HVAC tech in a previous life. Worked on all kinds of refrigeration systems from an R12 Toyota Tercel up to Grocery warehouses running on industrial ammonium. Not just some yahoo spouting off in here for his youtube channel.