2005 xlt ac problems

[rca510]

so we have had this 05 xlt expedition since mid 2012 runs good after engine swap. but lately the ac has not been working up to par. i added more freon last year but still noticed that it was not really cold at all or just enough t barely cool you off. the rear not cold at all. it tends to blow room temp. i recently added a bit more freon thinking it might have been low and i didnt have the rear ac going. but still warm coming out the back and barely cool in the front. i been reading the boards and noticed alot of the expeditions have problems with the rear ac. i been reading and checking on it and nothing solid to help me out. the only thing i can think of is the expansion valves. the lines to the rear hot to the touch with none feeling cold. cold that be my issue? or has anyone else done anything different to fix this issue...

 

[stamp11127]

Need static pressure, low and high side pressures when running.
Is the fan clutch working?
Correct number of fan blades on the fan for the application?
Is the condenser clean?
Fan shroud in place?

 

[rca510]

Stock fan and clutch as far as i know. Its working tried to stop it i think i might have chipped a bladed lol. Shroud is there. Pressure idk.

Sent from my LGLS991 using Tapatalk

 

[stamp11127]

The pressures will tell you if the system is low of refrigerant and the condition of the compressor.
Best thing to do would be evac the system and check for leaks, repair as necessary then recharge and check pressures.

 

[rca510]

Well i tried to put more freon yesterday and it was were it needed to be. Doesnt leak as far as i know. Ill see if i can borrow a sniffer to check for leaks

Sent from my LGLS991 using Tapatalk

 

[stamp11127]

If it doesn't leak, why add more refrigerant? Too much refrigerant can cause the performance to drop off quickly.

How are you determining "where it needs to be?"

 

[rca510]

Gauge on the bottle i bought. As for why i tried to add more. Well i am use to if the ac's arent blowing cold check the heat load. If not it needs more r134.

Sent from my LGLS991 using Tapatalk

 

[stamp11127]

The low and high side pressures are usually an indicator of needing to add refrigerant although if the compressor internals are crappy the pressures will also be down.

If you can get a set of good gauges it would be nice to know the low/high side readings and what the ambient temp is when take them.

 

[darmahsd]

What PSI is the low side supposed to be when the clutch kicks in?
Thanks,
Stephen

 

[rca510]

I need to get some gauges to check. But i do know the rear ac doesn't blow cold and the lines get hot as hell

Sent from my LGLS991 using Tapatalk

 

[darmahsd]

Not to hijack your thread, but my 2005 is having similar problems.
Barely adaquate with the fan at 2nd speed. I ask about low side pressure because when using the common blue ID charger with the guage, I can only get up to the beginning of the green line @ 25PSI. That's with one can which got cold, so you
knew something was working. The second and third cans wouldn't empty and stayed warm to the touch, and the guage never got deeper into the green zone, staying @ 25PSI. When I hooked up the unused can to my son's Ram 1500, it went well into the green closer to the red @ 50 PSI. I'm not prepared to spend medical prices to fix A/C.
Stephen

 

[stamp11127]

See sticky in Heating/Cooling for pressures.

 

[darmahsd]

I should have been more observant. Thanks for that, stamp.
It's 83° here right now. The low side pressure should be at
50-55 PSI. Barely makes it to 25, which is the beginning of the
green zone on this gauge. I don't have a high side gauge.
The refrigerant won't empty and doesn't get cold to the touch.
It's been laying in my garage since 2008, a sealed container.
Maybe too old and lost pressure. I'll go and get new cans and try again tomorrow.
I hope that's the problem. If I unscrew the full can slowly, it will evacuate into the air and shoot liquid. But it's hard to tell how much, if any pressure it's lost over the years. 134A going into the atmosphere is PC OK. That's why it was changed from R12.

 

[stamp11127]

Don't vent the r134a into the air - there is enough damage done already. The refrigerant doesn't go bad so don't waste your money on new cans. If it was ok to vent to the atmosphere then why have they started using r1234?

You need to have a good set of gauges in order to check your system so that you know what the low and high side pressures are. Notice the chart is giving both - they are both important.

If the low pressure switch "opened" due to low system pressure, it will "close" around 45 psi. Once closed the compressor will cycle as long as the high pressure switch hasn't opened.

 

[darmahsd]

I don't know what R1234 is, but they switched to R134A because R12 was
depleting the ozone layer. You're right in that enough damage is being done,
but leaving a pierced can on the gauge in the garage with kids running in and out
isn't good either. Throwing it out isn't an option, so I think the green police will
forgive me for letting one more go if I had to. I'll wait to get a good high pressure gauge.
If I'm hearing an on/off cycle, the pressure range is 5PSI to 20-25PSI, nothing near 45PSI. When I pull and hold the trigger in any combination, the can isn't emptying. When pulling the hose off the valve, you hear that momentary hiss, so there is gas in the line. The gas wasn't emptying into my son's truck either, and his low pressure readings for our ambient temperature according to that chart you gave me, are spot on. That's why I'm thinking that the old can might have lost some of it's propellent. Like old paint spray cans that you store. There's still good paint in them, but somehow the propellant leaks out over time. I've had some last 20 years, others not even a year. 'Don't know how that could happen with a sealed can that you have to pierce, so other than the A/C system being full, why would a can of refrigerant not empty into it at all?
Thanks,
Stephen