it depends on ambient temp. and condition of system. the only way to properly check your system is to put guages on it high and low to see exactly which side the prob is coming from instead of throwing money away.

 

Low side should not go below around 25 or the low press switch will cut the compressor out. Outside temp makes a large difference on what the high side will be , just like cluthc1 said.

 

i dont want to steal any ones thread but today i recharged my ac and it worked great i put in one can of the uv leak fineder and truck sat like 10 min then i started it with a/c on high and got a face full of 134a and tha edited by admin is nasty when it blows in ur face. so i will be replacing my evaparter core aswell any tricks thanx ,scott

 

You can go to Walmart and buy a fill line pretty cheap. or you can spend a little more and get a fill line with a little gauge on it. A set of gauges is best but I've done complete refills with just a fill hose and some cans. I've put it in until the air seems like it's getting close to cold enough. I would then close off the can disconnect the hose and get it out on the road to see how cold it gets. If it doesn't seem cold enough I've added a little more. Don't get greedy because you can overfill it and it won't cool as well.
I have gauges now. They were on sale for 39.99 at harbor freight last week.

BTW- 200K+ on my truck with all of the original AC parts.

 

The cycle time depends a lot on the ambient temperature. On a warm day, on high blower, a fully charged system probably won't cycle at all. With your system running, touch the suction line, (the part of the system with the accumulator) it should be cold if your charge is good. If the system is cycling much faster than usual, that's a good sign the charge is low. Working on these trucks for years, I have very rarely seen a failed compressor- they seem to last forever (unlike the cars and minivans.) Also, leaks seem pretty rare on 2nd gen trucks, except for evaporators of course, of which I've replaced dozens.

 

Sorry that I don't have the time right now to read the whole thread to see if anyone mentioned this.

My evaporator core had a leak (which is very common for our trucks) and I wasn't paying the dealer $1100 to replace it. I work for a refrigeration service company (commercial refrigeration, not auto) as a purchasing agent now, a tech before that. I mentioned my problem to one of the vendors that I buy from about the leak. He told me that he had a leak sealer that works without screwing up the system. We have heard this before but they never worked. He was so sure that he sent me the sealer for free to try. I was very hesitant to try it...but having a black truck, a 90+ degree week of heat I decided to give it a try.

IT WORKED and a year later everything is still working fine.

Now the problem is I am taking a vacation day today and the box that the sealer came in is on my desk at work and I can't think of the brand to post a link for you guys.

Since I used it three other guys at work, all A/C tecks have used it and also had good results. We have always heard or found out from experience that A/C systems sealers are just a band-aid and will cause other problems down the road but this stuff really does work.

But it takes a few tools that most people don't own but can be rented from Auto Zone or places like that. A vacuum pump and a set of R134 guages are a must to use this sealer. Actually you should take your truck to a place that can evacuate your freon if there is still any in your system. Mine all leaked away so I didn't need to drag our evac system out to the parking lot.

It works, I didn't think it would. I did this a year ago, checked my A/C yesterday, still full charge and the air temp at the vents was 46 degrees with the outside temp at 85. It may have gotten cooler but I only drive 5 miles home from work.

 

Make sure and post up the name of the product when you get back, please-------I'm like you, hesitant to use a leak sealer, but coming from a tech, I might have to give it a try.

 

Well it hit the 90s yesterday and today so I bit the bullet and took the truck to my mechanic. Very low on charge - about half a pound. Once filled up, very nice. I swear I felt like the whole truck ran much better afterward.

 

If it's getting "cool, not cold" then it is most likely low on freon.
Normally the AC will cycle as long as needed, to maintain a certain temperature. If it is 105° and humid out, then it will cycle longer than if it is 80° and dry.
If it is low on freon, the pressure will drop too quickly, and the low pressure cutoff will shut off the compressor.

You might also check and see if your blend door is closing all the way... If it is allowing hot airflow, then it will never get cold.

I would get a good gauge, and check the low side pressure, and add freon as needed. If that doesn't help (it probably will), then it is time to check out the blend door... I can't help much on that one.

 

The problem with the sealers is that most react to air.. or some to moisture... They are the death of a recovery/recylce machines... You can run into trouble if you open the system up for repairs.. They actually make a tool for detecting sealers, so they don't get pulled into recovery machines...
The dye is one of the best ways to find leaks.. but sometimes they take a while to show up...
Another good practice is the flush the systems when you have it apart..
The issue with flushing is using a good product.. and getting all of the flush out of the system.. some manufactures are recommending that you just replace all of the components... (sounds like they are just trying to sell parts.)
My truck was low from the factory... wife was complaining about it... I kept telling her it was just hot out side... So pulled it all out.. it had about .5lbs in it... (That was in 03).. I pulled it out a week ago.. and it was a little low again.. (1lb) and filled it back to the recommended amount.. If you have access to a vaccum pump.. run it for at least 30mins.. (I usually try an hr.)

Oh, yea.. good luck on the changing that ofice tube....

Bryan

Edit... your pressures are going to depend on temp... and humidity... and air flow.. make sure those condensors are clean.. and the fan clutch is working..

 

I found it online.

Click HERE.

 

I was just curious if this stuff was still holding up to the claim?

 

It would be nice to know. Hot here, 90's everyday. No air. Be nice to have a quick fix. Skeptical though.

 

It will take about 8 hours of work or less to change the evaporator coil. You'll see why it fails too by all the dirt and leaves laying up against it roting it out.

 

02 Dodge 2500
My a/c has defaulted to defrost mode. I have a vaccum line on the passenger side under the hood by the firewall which is broke. I can not locate the other end. I assume it is in the cab on the other side of the firewall. Do you have any suggestions? Must I prepare to remove the dash?

js