AC needs help and advice for 2007 5.9 CTD.

[HerbW]

Hi. My AC doesn't work. I took it into Jiffy Lube and they pressure tested it for $50. They said it tested great. So I had them vacuum it and recharge for a total of $149.00. This worked ONE day.
I have tried dye and have looked everywhere even watching for it to drip from the evaporator drain. Nothing! I'm ready to put pressure in the low port and look for bubbles with soap.
Is there a way to see evaporator without removing the dash?
Any ideas on fixing? The Freon 134A lasted one day and now too low to even turn on the pump. Should I buy an evaporator before I tear apart the dash?

Any suggestions are greatly appreciated. Thanks, Herb

 

[jhenderson]

Find the leak 1st. Too big a job to change the evap unless it's bad.

 

[MMeier]

Are you positive it is actually losing freon, or is it another issue ?

 

[JR]

Is the compressor cycling when you turn on the a/c button? If not you likely have a big leak. Find someone with a set of gauges and test both the high and low side. Also take note of ambient air temps when you test. This will give a good idea where to go next and what to look for.
You can buy a set of gauges yourself for relatively cheap if you work on your own vehicles alot. You can at least do basic troubleshooting and charge your own system (although you will still need to find someone to draw a vacuum before charging if you open the system up for anything.

 

[HerbW]

Is the compressor cycling when you turn on the a/c button? If not you likely have a big leak. Find someone with a set of gauges and test both the high and low side. Also take note of ambient air temps when you test. This will give a good idea where to go next and what to look for.
You can buy a set of gauges yourself for relatively cheap if you work on your own vehicles alot. You can at least do basic troubleshooting and charge your own system (although you will still need to find someone to draw a vacuum before charging if you open the system up for anything.

Hi. Thanks for all the replies. I took it back to Jiffy lube today and they said it seemed to have lost the freon again and has a leak somewhere. They said it's strange as the pressure stayed constant without the compressor running. If I add a can of 134A it will bring up the pressure enough to let the compressor relay work again and cold air happens again. Everything seems normal again and the truck will chill right up. Tomorrow it's crap again.

Could the compressor only leak when it is engaged?

 

[JR]

Herb I'm no a/c expert I only know what I've learned from working on my own systems, but I don't see how that could be possible. A leak is a leak and it should vent off regardless if the compressor is running or not. Did you see them pull a vacuum on it? Any leaks you had should have shown up if they held the vacuum for any length of time.

 

[HerbW]

Hi. They pulled a vacuum twice on it for five minutes each time. I told them the Carfax showed AC service each year for two years prior to me owning it. When it's not running, I see pressure just below necessary pressure to operate and seems to hold constant. I took the passenger battery box and air filter box out to follow the lines out. Seems fine. Where the one line touches the corner of the filter box, I put split tubing on it for protection and tywrapped it. The filter box had put a slight groove in it but no leaks.

 

[MMeier]

Hi. They pulled a vacuum twice on it for five minutes each time. I told them the Carfax showed AC service each year for two years prior to me owning it. When it's not running, I see pressure just below necessary pressure to operate and seems to hold constant. I took the passenger battery box and air filter box out to follow the lines out. Seems fine. Where the one line touches the corner of the filter box, I put split tubing on it for protection and tywrapped it. The filter box had put a slight groove in it but no leaks.

IMO. 5minutes is not long enough. I always shoot for at least 30 minutes to make sure it's holding .

 

[mwilson]

X2......30 minutes at 30 in.-HG.

If it does not hold then you have a leak.

 

[mwilson]

You may have to take this thing to an A/C specific shop, they will have Nitrogen for a test gas and a sniffer to find the leak.

Mike.

 

[Bob V]

Check the Schrader valves at the low and high side ports. If they are checking the system with the gages hooked up to them it will test fine and then start leaking when disconected.

 

[JR]

Hi. They pulled a vacuum twice on it for five minutes each time. I told them the Carfax showed AC service each year for two years prior to me owning it. When it's not running, I see pressure just below necessary pressure to operate and seems to hold constant. I took the passenger battery box and air filter box out to follow the lines out. Seems fine. Where the one line touches the corner of the filter box, I put split tubing on it for protection and tywrapped it. The filter box had put a slight groove in it but no leaks.

They wasted your money if that's all the longer they drew it down. Like said above 30 minutes should be the minimum but the longer the better. I have a friend in the repair business and when I need a/c service I will do the work myself at his shop. He will do a flush if needed and draw a vacuum and we will leave it sit for an hour or more if possible. This will draw any moisture out of the system that may be present. This step is especially important if the system has been subjected to the atmosphere at any time, and more important if it was open for a long period of time. Moisture in an a/c system will form hydrochloric acid and corrode everything from the inside out.
If I have to replace a compressor in anything I also replace the receiver-drier (or accumulator) along with the expansion valve. Most companies will not honor the compressor warranty if they are not replaced at the same time along with a flush. They are relatively cheap and are usually in need of replacement anyhow if the compressor is shot. When the compressor pukes the reeds internally it will take out the other components and replacing them along with a good flush and vacuum are the only real fix.

http://www.discountacparts.com/

I have bought kits through these people for 4 vehicles over the years and haven't had any issues to date. Their equipment is of good quality and the prices are hard to beat.