Lost A/C this year

[Fast Eddie]

2004 Ranger, 3.0, 5mod, 95k mi
Went to use it for the first time this year and nothing but hot air. Not a hint of cooler air at all. I flipped through a few youtube vids and found one similar to my problem. Clutch engages/disengages every few seconds. He showed how a recharge fixed it. I still had some recharge left from 2017 and tried another charge. I'm not sure how much was left in the can but figured it might be enough to see if a charge was the problem (cool but not cold air). No dice. It also didn't seem to improve the gauge reading while recharging. It would always drop to 25lbs when the clutch engaged.

I suspect a leak but no way to prove it. If it's the evaporator. I may never find it without ripping out the dash. Not going there.

1. Does A/C stop leak work and, if so, which is the best?
2. Will the stop leak mess anything up if it only needs a charge?
3. What is an oil charge and should i use it?

The reason I ask is I'd rather just go ahead and use stop leak and then recharge the system with hope that works rather than burn a whole can of recharge to find out should have used stop leak. I just want to mess anything up in the process.

Thanks in advance.

 

[Uncle Gump]

My system on the 06 has a small leak I just can't find. I've tried.

After a couple three years the performance drops enough I know it's low. I check for leaks and find nothing. I add enough to bring back performance. At some point the leak will be found... but until then I'm just not throwing hundreds of dollars at something I don't know will fix it.

I'm not big on sealer type fixes for anything... including A/C systems.

 

[RonD]

Stop leak can work if its a small leak, problem is the high pressure side of the system, it can go above 300psi on a warm day
No it won't hurt anything

Evaporators rarely leak as they are on the low pressure side of the system
Condenser and high pressure hose seals are usual suspects for leaks, because of the 300+ PSI

A pressure chart seen here: https://www.acprocold.com/wp-content/uploads/2011/11/Temp-pressure-chart-33776F1.jpg

As "freon" is lost from a leak the low pressure side drops too low which shuts off the compressor so its not damaged, the "freon" has oil in it
Compressor needs a constant flow of oil thru it or it will burn out, this requires a pressure above 25psi on the low side

Most refill cans have a dye in it now a days which will show up at leak points, make sure you use refills with that dye

 

[Shran]

Every AC guy I've talked to says stop leak will make things worse over time and contaminate the system. You have two options:
1: if it's a very slow leak, just recharge it and live with it
2: larger leak: find it and fix it. Could be something simple. My work truck was losing a huge amount of refrigerant and it ended up being the Schrader valve on the low side port... a 15 cent part.

Does it need oil? Not necessarily. Virgin R-134a does not contain stop leak OR oil. Many "recharge" kits contain refrigerant, stop leak and oil in one can - read the label to see what you're getting. Personally I would just buy a can of R-134a with nothing else in it and use that and nothing else for a very slow leak.

A tip if you're needing to put in more than one can: while you are introducing your new refrigerant into the system, you can set the can in a bucket of warm water. This will help it move from the can to the AC system MUCH quicker although you have to be careful and watch your pressures because it is easy to overcharge it.

 

[RonD]

A person that repairs AC systems for a living would have to be an idiot to recommend a Stop Leak product, it would be the same as sending a client to another AC guy
They should say its bad and ruins the system, if they are smart
So grain of salt on what they say about those products

Been thru the same with Stop leak products for cooling systems, or head gasket leaks, products do work for SOME leaks but not all

And "trans fix" for automatics, swells gaskets and seals to get pressure back up(internal leaks) and does work for some issues

And no harm done since you would flush the system when doing a proper repair
They are all just temp fixes, and no professional mechanic would or should recommend any of them, its not in their best interest to do so


Back a few years, I got a stone chip in the windshield, had read about using a resin to fix it, asked my local glass guy about it and he said "NO WAY, windshield is structural, its the devils work you are asking for!"
Now, fixing chips and cracks in windshields is one the biggest parts of his business
I asked about what he had said before, and he said "well the product is better than before"

If you are a professional then you need to protect your profession, so grain of salt

 

[mikkelstuff]

Don't forget, front compressor seals can leak. Those may be difficult to spot.

 

[Shran]

If you are a professional then you need to protect your profession, so grain of salt

I hear and understand that. Just not personally a fan of "stop leak" and mechanic-in-a-can type stuff in general. I will use the example of radiator stop leak that basically just clogs up the entire radiator.

One of my co-workers used the head gasket repair stuff and it worked for about a year and left him and his wife stranded. I just don't trust any of it.

 

[Fast Eddie]

Thanks to everyone for chiming in. It helps. The low side fluctuates between 25 (low) and 45-55 (alert) depending on the state of the compressor (engaged/disengaged). I failed to include that info before. Should I change course based on the new information? I found the refrigerant with a dye in it but it's UV dye. I'm going to need to invest in a blacklight?

 

[RonD]

You can get UV flashlights

Leaks in a condenser seen here: https://spectroline.com/wp-content/uploads/2018/06/AC-Leaks-Revealed.jpg

 

[Fast Eddie]

Wow -that's right! Condenser sits in front of radiator so might have taken a hit? I'll do the dye and crawl around to see if anything pops out. Any rule of thumb how long this takes to get through the system? Idle for 10 minutes with AC full blast?

Plan on using this

 

[Uncle Gump]

It should say on the can... I'm sure it has some instructions.

 

[Fast Eddie]

I was watching a video to get ideas on where to look for leaks after @RonD posted the pic. The guy in the video said if you're going to add refrigerant when there's no leak, you want to pull a vacuum on the system so there's no moisture but doesn't go into what that is or how it's done. Anyone know what he's talking about?

 

[Uncle Gump]

Yes... we do

 

[Uncle Gump]

Lmao!

 

[Uncle Gump]

Your system already has some refrigerant in it. Not necessary to pull a vacuum.

Only required when system is empty after being opened up. And... it's not just to remove moisture... but also air.