AC Compressor Not Pulling Freon

[gpracer1]

thanks letsbangout so just put a can on there and even with the compressor turning on and off every few seconds it will still suck in the freon from the can, I think I will buy a better quality short yellow hose from NAPA that goes from the can right into the low service port rather than using my cheap harbor freight gauges and the long middle six foot yellow hose that is attached to them, (that's too much room for air to sit in and re enter the system) and it should be way better than the silly blue one with the gauge on top that comes with some cans when you buy em that way, called a shop today and they quoted me up to $1,200 bucks to have it diagnosed, troubleshot, fixed, evacuated, vacuumed, pressure tested, and re charged. I am trying to do it for a third of that cost myself.

My only worry / concern now is over filling it, but at 25 PSI I am a long ways away from the 60-70 PSI on both sides when equalized and full with engine off. Or the 20-30 PSI low side and 120-170 PSI high side with the engine running and AC on obviously.

Just so you know, the static pressure of freon ( when the compressor is off) is equal to the temp of said freon. It does not matter if you have 2 cans in the system or 13 cans, it is the same. Therefore you can't gauge how much is in it unless the ac is running.
Even then the low and high side readings need to be compared to an ambient temp graph for 134a.
This is why you really need to know what you are doing if you want ice cold ac.

 

[jayman8200]

I dont want to hijack the thread, but since we are talking about AC, I have a question. I have a leak somewhere in my system and cannot find it. my system was completely empty, so i put 1 can of with green dye in it and would kick on and off. the next day i went and got more thinking it wasnt cycling through the whole system, got an 8oz can with red dye and sealant, put a can of oil in it first, then put 3 reg cans of freon and got it fully charged, blowing good out of the vent, a day later it is warm again, but i cannot find any dye on any of the lines. are there any diagrams of the entire ac system to see if i am missing any?

 

[JenneK]

Probably your evap core. Remove the HVAC fan and look towards the left. Maybe you'll be able to spot the dye.

 

[gpracer1]

Probably your evap core. Remove the HVAC fan and look towards the left. Maybe you'll be able to spot the dye.

Yup, that would suck. Also check the front of the compressor by the clutch.

 

[jayman8200]

ok, i pulled out the blower fan to look at the evap core and didnt see any dye. i am so dumbfounded...the only dye i see is under where i charged it, back of the compressor..i think it was spray from when i was charging, but could it leak from back there?

 

[jayman8200]

where are the lines for the rear that i can check to see if maybe it is leaking out of there. since i cant find the dye there maybe it is coming out of the rear air...does anyone have any diagrams on the rear ac system?

 

[Gregski]

I dont want to hijack the thread, but since we are talking about AC, I have a question.

Hijacker !!! LOL, jk

---------- Post added at 07:58 PM ---------- Previous post was at 07:57 PM ----------

Don't want to beat a dead horse to death, but often times a thread sounds like just what your problem is and then you never see what happened, what the solution was, well this won't be that thread, I won't let it.

So with the system reading 25 PSI on the low side and 25 PSI on the high side with the vehicle idling, I threw in the towel and took in to a shop, an independent shop not the stealership.

Here's what they found, when they measured the pressure they said it was 11 PSI on the low side and 100 PSI on the high side, with the engine idling at 2,000 RPM. So basically low on freon.

Well first lesson is that the Harbor Freight gauges are ****. Not only do they read incorrectly but they only go up to 36 PSI on the low side and 90 PSI on the high side for 134R. The pro gagues go up to 300 on the low side and 500 on the high side, but more importantly read accurately.

The second lesson is that we need to have the rig reved up to 2,000 RPM to take accurate measurements.

So for $230 bucks (the cost of a decent gauge set) they evacuated my system, pulled a vacuum, checked for leaks (using two methods, vacuum, and a $600 dollar leak detector) and filled the system. No leaks were found!

Now the Low Port Pressure is - 25
High Port Pressure is - 150
Ambient Temp was - 75
Center Vent Temp blows - 40

Third lesson, in my opinion a 12 oz can is no 12 ounces. Neither can you fill up your system from completely empty with those stupid cans, it may take 7 cans or so, plus you get air in the line every time you swap a can. So they may be ok for topping off a system when it's a little low but that's about all. Think of spray cans of paint, you can paint some chassy parts with it but you wouldn't paint a car with them. (Flat black excluded, LOL)

I hope this information and bench marks help someone in the future, I sure learned a lot. I don't normally mention the name of the shop but in this case Polar Bear Auto Care gets my big thanks as do all of you for reading and trying to help, stay cool!