A few years ago I went through the ac system and redid everything. Strong cold air for years. This year, I barely get anything. Is there slightly but barely. Compressor is cycling on and off but not a lot of cold air.

Could it need a recharge or is something else going on?

How many years should I get between servicing an ac system?

Cycling compressor is tell you that your freon is low. When recharged properly the compressor should run solid not cycling in and out. So this is a clue that you have slow leak some where. It's really easy to do a o-ring change and typically fix it the first time.

and a gas engine with an available vacuum line can be a great vacuum pump.

Renting a pump from auto zone is free.

I'd rather use a good vacuum pump and leave it suck a vacuum on the system typically for at least 15 minutes. Then shut everything down and leave it sit for another period of 30 minutes or so and check and see if the vacuum held or not. If not then repair the leak. If the system already had some pressure I typically add shot of UV dye and enough freon to run the compressor.

 

Like my last job on a Subaru...

 

If you add one can (12 oz / .75 lb) of 134A @ $8-$12 and it lasts a year don't do any thing else. If it lasts less than 4 mo. then do like Mike did. It's more of a major leak and needs repairing.

If you add one can (12 oz / .75 lb) of 134A @ $8-$12 and it lasts a year don't do any thing else. If it lasts less than 4 mo. then do like Mike did. It's more of a major leak and needs repairing.

 

Or you could be like a local here that kept dumping can after can into the system. Every spring its 3 cans of freon in 5 years at about $11 a can totals out at $165 in freon. But it only took a simple $10 o-ring kit to fix and no longer leaking. So is it worth tracking down? Sure it is when a o-ring kits are cheap and you don't have to continue the cycle of throwing money out the window.

If a person doesn't have a leak detector, A/C gauges, vacuum pump, hand tools, and most important THE KNOW HOW then dumping in 3 can a year might be cheaper than taking it to a repair shop and paying over $250.  ALLDATA  time guide 1.4 HR evacuate & recharge, .6 HR replace all O- rings plus the cost of parts and 134A, and I charge $100 / HR and mark my parts up.

THE KNOW HOW then dumping in 3 can a year might be cheaper than taking it to a repair shop and paying over $250.

 

That why I'm willing to provide the know how. Just up to you to get the work done. Funny thing is this morning I get to do a o-ring kit on a Ford diesel and get him ready to head back to North Dakota.

 

 

If a person doesn't have a leak detector

 

Can of UV dye is rather cheap and black light flashlight is cheap too.

 

 

A/C gauges, vacuum pump,

 

Here is where the money get spent I will admit the manifold gauges and vacuum pump can get you for about $250 to $300 depending on brand.

 

hand tools

 

Everything else is standard hand tools except the the collar to release the couplings. Those are also fairly cheap at a part house.

 

ALLDATA

 

If you got that book you have all the knowledge you need to get the job done...

Thanks for the info fellas. The wife was helpful in reminding me what was going on. When I did the ac service work back those years, the mechanic said I had a small leak in the compressor. The money required to replace the compressor was significantly more than just adding an occasional can of 134a.

Went to the local auto store and picked up a can and another can with oil and stop leak. Used the stop leak can first and put in maybe half a can. This was little fart can. So all in all, it did not take much to get my as back. I've got more on hand if needed. But given I Went 4 years since the last time, we'll see.

I gone down that road already. Replaced everything else once but came down to replacing the compressor and now I have leak free system.

I bought one of those bottles from Carquest that comes with a gauge and I filled the system, its been super cold ever since.  ;)

I bought one of those bottles from Carquest that comes with a gauge and I filled the system, its been super cold ever since.  ;)

 

Be careful... Some of those contain oil charge as well. When mine was leaking years ago I grabbed those shot the can in and was happy after about 5 can you now have a system full of oil and no freon. Can cause serious damage like hydro-locking the compressor or extremely high pressures that can be explosive. Mine was enough that it was capable of squealing the belt and venting oil and freon out the back side of the compressor. So like I said be careful.

Yea, definitely. Some of the cans only have refrigerant in them, although. I barely used half a can of a small one that had a mix of everything. I did small increments of adding until the compressor started working continuously again. Then went in and felt the air on the cab and it was ice cold.

Remember the lower the lo side pressure the colder. But Dodge has lo pressure cut out at about 25-30 PSI so I typically charge to 35-40 PSI so it nowhere near the freezing temps and keeps the system sweating not icing. More freon will make it warmer. Don't get carried away though.

 

Wow those pressures are WAAAAAAY off what I've been seeing. Last charge I did at 91 ambient with 66%RH saw like 190/35 and 44* outlet temp. 

Like said on the bottom of the table...
 

 

If pressures are LOWER than shown, but center panel outlet discharge air temperature are okay, then A/C system is okay.

 

Personally I would of nudged the high side pressure up just a bit more just passed 200 PSI for those temps. No higher than about 250 PSI. More or less getting a balance of liquid to vapor in the system.