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Hi friends,
I tried to post these pics in another thread but when I was done the post disappeared so I decided to start a thread for A/C recharging in persuit for Max Cool temps.
Got another set of gauges last year and they have been sitting here until another thread inspried me to get off my butt and try them out since
my A/C blows cool but doesn't feel like it's as cold as it used to be.
I plan on picking up a can of refrigerant this week and bumping up the charge to see how cold I can get it compared to outside temp, below are my working pressures and the hookup showing a heathy system with line pressures in the proper pressure regions on my 2004 R330 @ 155k miles.
I'm looking to achieve Max cooling for the summer.
What kind of vent temperatures is everyone getting from their A/C???
Also, what is your temperature split from outside ambient temperature to inside measured vent temperature?
In 2019 I replaced the Dessicant Bag in the Condenser. Evacuated the system to do it. I figured why not, the car is 10 years old, the bag must be a bit saturated and dirty by now.
Pain in the *** because I couldn't unscrew the cap on the condenser without removing the fans and unbolting the radiator to lean it back far enough to completely remove the condenser.
The original dessicant bag looked to be in very good condition, just a little dark from the system's oil. Replaced the o-rings and reinstalled the condenser, fans, etc.
Put a vacuum on and refilled to the exact capacity.
A/C was colder, less than 40 degrees coming out of the vents consistently, like 38. Remarkably cold, actually. So it must've been a bit low before I evacuated the system, which is normal for 10-11 years.
btw, I grab a few cans of R-134a at Walmart every time I go, which isn't often. $5. Who knows what's going to happen to price and availability of these refrigerants. R-12 is big $$, R-22 is outrageous, and now they're already phasing out R-22's replacement, R-410a. R-1234, or whatever it is, taking R-134a's place, now.
btw, Margate, did you happen to check out the "Air Gap" for you AC clutch?
I'd guess your Compressor gets year-round use in Florida.
It's something to check out on our older cars. My RX is still within tolerance (.010-.024 in.)
My 01 Navigator's AC clutch is just out of Ford's acceptable range at .033in., but still engages okay.
In 2019 I replaced the Dessicant Bag in the Condenser. Evacuated the system to do it. I figured why not, the car is 10 years old, the bag must be a bit saturated and dirty by now.
Pain in the *** because I couldn't unscrew the cap on the condenser without removing the fans and unbolting the radiator to lean it back far enough to completely remove the condenser.
The original dessicant bag looked to be in very good condition, just a little dark from the system's oil. Replaced the o-rings and reinstalled the condenser, fans, etc.
Put a vacuum on and refilled to the exact capacity.
A/C was colder, less than 40 degrees coming out of the vents consistently, like 38. Remarkably cold, actually. So it must've been a bit low before I evacuated the system, which is normal for 10-11 years.
btw, I grab a few cans of R-134a at Walmart every time I go, which isn't often. $5. Who knows what's going to happen to price and availability of these refrigerants. R-12 is big $$, R-22 is outrageous, and now they're already phasing out R-22's replacement, R-410a. R-1234, or whatever it is, taking R-134a's place, now.
It was almost 100F again today so I waited for it to cool off and it's now 84F outside.
Thank you for posting your vent temps I was hoping our Jap cars would hit the low 40's!
Did you feel it really needed the d-bag or would you have skipped it if you could do it over?
Reason I ask is we were always required to do it for every car that was evac'd even if just replacing an orfice tube or leaking schrader but I always wondered if it was really necessary if the system wasn't left open for long.
Yeah I'm not there yet, she needs work check this out.
Yeah, that's too warm. You should be in the low 40's.
Was that temp after you put in about half a can? What did the High Side pressure go up to?
Is your condenser clean? No leaves and bugs stuck in the fins?
The original desiccant bag was in good overall shape -- cleaner than I had expected. But my RX only had 43K miles on it in 2019. It did not need replacement.
If the air coming out of your vents doesn't smell musty and can clear fog from the inside windows (defrost mode) quickly, your Drier is in good shape.
To answer your question about temperature differential, I assume you're wondering if the AC can still blow really cold air when it's really hot, like 90-100 degrees outside.
Yes. My RX has no problem blowing really cold air even in the 15-20 really hot days (90+) we get here in the Summer in the northeast.
Yeah, that's too warm. You should be in the low 40's.
Was that temp after you put in about half a can? What did the High Side pressure go up to?
Is your condenser clean? No leaves and bugs stuck in the fins?
The original desiccant bag was in good overall shape -- cleaner than I had expected. But my RX only had 43K miles on it in 2019. It did not need replacement.
If the air coming out of your vents doesn't smell musty and can clear fog from the inside windows (defrost mode) quickly, your Drier is in good shape.
To answer your question about temperature differential, I assume you're wondering if the AC can still blow really cold air when it's really hot, like 90-100 degrees outside.
Yes. My RX has no problem blowing really cold air even in the 15-20 really hot days (90+) we get here in the Summer in the northeast.
My condenser looks good and clean but everything looks original and I'm really not wanting to pull it out and do the extra work so might skip that step but my car has 155k miles.
I haven't charged it up yet but with sub 40's vent temps possible on our cars according to your readings has me encouranged to do an evac and recharge with fresh juice.
To be honest the compressor is getting some age on it since I can hear the classic hum of a tired compressor but hoping I can get a couple more years out of it.
I will also have to look up the clutch gap procedure since I haven't done anything yet to the system unless you'd like to post how you did it for us.
One more thing I'm not thrilled about is the time it takes for the line pressures to balance when the engine is shut off, I was expecting faster but maybe it's just our cars, I will have to do more tests.
One more thing I'm not thrilled about is the time it takes for the line pressures to balance when the engine is shut off, I was expecting faster but maybe it's just our cars, I will have to do more tests.
I think sometimes that's an indication of bad TXV. But who knows, maybe it's normal.
I like the idea of doing an evac, vacuum, and then filling it up to spec. However, me personally, I'd throw in a few ounces to see what happens with temp and pressures, and confirm the system can function properly before committing to an evac/refill and then later figuring out an existing issue such as a bad TXV or bad compressor, etc.
From your first post, I think we can rule out major leaks. That's good. Your compressor runs. That's good.
Your car is old, so it's likely to have normally lost a good amount of refrigerant over the years, (unless you know when the last time it was serviced).
That's good, too. Because it means all you need is to refill to the proper amount and your AC system should function well.
I bought my 2001 Navigator new. By 2014, it stopped blowing cold air. The system had "lost" half of its 56 ounce charge, but no major leaks. That's about two ounces a year. Today the AC still works and blows cold air. Old cars lose refrigerant without major leaks and can be recharged and give more year of service.
Checking the clutch air gap is very simple, for any car.
Our compressors are easy to get to, too, from the top under the hood (unless it's different on the 330).
Here are pics of how to locate and measure the AC clutch air gap on the RX.
Bottom pic shows the .016in feeler gauge stuck in the gap, which is in the middle of the accepted range. Normal for a car with about 50K miles, I think.
Here's a pic from tonight showing AC blowing air in the 30's on a warm and muggy Summer night.
83 degrees outside, 82% humidity
Re-Circulation On (no fresh air)
Thermometer in left vent reads 35, right vent reads 37.
The temperatures fluctuated between 35-42, depending on if the car was moving or sitting idle.
I think sometimes that's an indication of bad TXV.
I think my TXV expansion valve is flaky or sticky, I'm not 100% sure yet but this just got a whole lot more interesting.
Am I killing my A/C by not running it enough???
What ya'll think,
It's hot down here in S/ Fl but I never use the A/C because I like those Swisher Sweet cigars so I drive around smoking my cigars with the windows down so it doesn't smell the car so bad when my wife has to drive it.
However, my wife only drives the car once a month to the store 1.5 miles and back and that's the only time the A/C is run, maybe 10 mins to the store and back once or twice a month max.
The other day I got caught in the rain so that's when I rolled up the windows and turned the A/C on max and noticed it wasn't blowing as cold as it should.
I know it may be a little low on charge and went to the store to get some R134a. Bennetts Auto was out of stock and said the plant was shut down and only had some cans with dye for $16 per can. So I drove down to Advance Auto and went ahead and picked up 5 cans at $5.99 ea to keep on the shelf.
Temp is 95F and the whole drive the A/C vent temp never dropped below 60F at idle or 56F at 45 mph with A/C on max, windows rolled up, and recirculate was on- this was the best it would do.
So I'm thinking no problem I'll give it a recharge when I get home.
Magically when I was 1/2 mile from home it's like someone flipped a switch, the temp dropped to 47F in just seconds.
For the rest of the drive and idling at home the temp was bouncing 48F-54F and finally settled at 52F and held at idle and raised idle.
Ideas and theories are invited!
Anyone ever seen a flaky expansion valve on our cars???
Maybe something else??
I gave it about a 1/2 can charge and bumped it with juice slowly until no further improvement in temps can be seen and it is holding at 40F at idle and raised idle and I will continue to monitor it the rest of the week for bouncing temps. It was a little low but the compressor is not cycling and the line pressures(low and high side) are in spec and not bouncing either. But I had no way to monitor the line pressures while driving while vent temps were bouncing.
You got it to 40 degrees! That's darn good for Florida.
From what little I know about AC's, I do believe that the fabric of the desiccant bags (or the felt filters in those rec/dryer cans with the desiccant media) in the Receiver Driers become hard and crusty over time -- kinda like a liver when one drinks too much booze -- causing a Restriction in the system. I think this hardness gets worse the less you use the AC. However, running the AC could, theoretically, break up or loosen up the contents of the desiccant sack if it's not too far gone. I imagine it like a dried out old sponge -- soak it in water and its "spongey" again doing spongey things for you.
Also, I always told to run the Defrost in the Winter up here because it's good to run the AC and get the oil flowing and keep everything lubricated in the AC system. I dunno.
This is the original receiver drier desiccant element, 10 years old, 43K miles. The dirtiest part is the bottom of the element where it sits upright in the condenser. Still relatively clean, soft, and supple.
It was in the low 90's again today.
At the stop lights the vent temps drift up to 44F but going down the road at 45 mph it stays steady at 40F like the line is painted on the thermometer, no sticky glitchy action.
I will keep monitoring it for next few weeks and appreciate the feedbackand tips.
I might go ahead and pick up an evacuator.
Anyone have any recommendations???
Harbor freight has one with excellent reviews and the Robinair I can get on line for a few dollars more has good reviews too but I have always been a huge Robinair fanboy since it's what I started with and they been around decades but I don't know if their products are good as they used to be.
Um, almost everything has high ratings on Harbor Freight. Amazon's ratings are fake, too, in my opinion.
But anyway, I have the 3CFM Two Stage HF vac. I'll admit it worked great both times I used it. I chose the 2-stage over the single stage because I figured it might be a bit beefier and not ****** the bed on me in the middle of a vacuum. Got it used "like new" off ebay.
The little red $18 vacuum pumps are junk. But even that piece of garbage waste of money and time has over 4 stars on HF.
Looks like AutoZone and O'Reilly both rent Vacuum Pumps. Better than buying china junk. Just make sure you buy new vacuum oil for it so it can perform its duty well.
08-09-21, 08:30 PM
A/C Recharging for Max Cool Temps, with gauges
