AC not working

tjkj2002 · **Posted:** Tue Jun 27, 2017 5:12 pm

geordi wrote:

The filling is not quite as precise as someone above likes to say it is - he works for a chain place that loses money when people DIY. Measuring the pressure from both the high and low sides is the precise way to know it is full and working properly if you aren't fully evacuating the system, but the high side also varies with outside temperature, so you CAN properly gauge the fill with only the low side number that this gauge will give you.

Actually I make huge $$$ from DIY'ers,when it all goes wrong which is most of the time.

You can't judge a properly filled system by the pressures,to many variables(altitude,ambient temp,and humidity just to start) can effect those #'s,and sometime pretty drastically not to mention a compressor going or a partially plugged orifice tube can throw those #'s way off but still work enough to produce cool air.At that point where the AC works "well enough" can cause other issues like evap core freezing.Overfilling greatly increases the chance to blow the compressor apart(seen this more times then I can count).

As little as 2-3oz can make a AC system not work properly,depending on system size, and there is no way to to know how much is in the system already without evacuating the system and weighing what came out.

Again the system is not filled by pressures but by weight.

Jpd686 · **Joined:** Tue May 30, 2017 12:14 pm **Posts:** 50

ok so another update, i got that kit and hooked it up to the system. It was showing 30PSI. So after looking around a bit and leaving it running with ac "on" the compressor IS cycling, not staying on though, it basically is staying on for 2-3 seconds then shutting down for about 5-10 seconds... The LP side pipe is cold to the touch. When the compressor turns on the pressure drops down to about 20 PSI, then back up to about 30 PSI. I tried adding a very small amount to see if anything changed, it did not change how it operated, still warm arm coming out of the vents and now is reading 35PSI and dropping to 25PSI (approx)

It also sounds like air is coming out from somewhere when the compressor kicks on, i cant find any obvious spots but i can deffinatly hear something and its consecutive with the compressor turning on. :S Sounds like its coming from either the canister, or somewhere along the low pressure line but that doesnt make sense cause then would it not leak out all the pressure from the system anyways??

any other ideas?

geordi · **Posted:** Tue Jun 27, 2017 10:22 pm

Sounds like you have developed a leak on the high side that only presents itself when the system is running - high pressure is north of 150 psi in a properly running system, and it wouldn't take much of a leak to bleed out the system. If you can hear it though, that is a significant leak.

You can do two things at this point - Put in a can of gas with dye, knowing that you will be leaking down. If the pressure is only at 35psi when the system is off, either your gauge does not have a good connection to the schrader valve (it happens, some are deeper than others) or the system is just really low. Static pressure when the compressor is off should be around 90-100 psi depending on temperature. Since the AC system is sealed, the humidity outside doesn't matter to the pressure readings - it either has pressure or ti doesn't, and hot temps raise the high-side pressure because the compression can't shed the heat (in the condenser) as easily.

When a system with dye leaks, the dye will come out and glow when under a UV light, it will make the leak pretty easy to locate. It may be helpful to look for the dye at night or in a dark garage if that is an option - seeing it during the day will be difficult.

The other thing you can do is replace the high pressure hoses. I had a leak on one CRD that was from where the high pressure hard line bolted to the compressor on the driver's side (one bolt and an o-ring seal) because the aluminum manifold (little block of aluminum) that the hose ended at... Was just PRESSED onto the hose during manufacturing and it started to move and worked itself to a leak. Not a great design for the connection... But hey, it was cheap for Chrysler. That hose crosses the top of the radiator and bolts to the AC condenser at the front passenger side of the condenser. Not hard to replace, but the system will need to be vacuumed down and refilled completely when you do that. If you are going that far, you might as well replace the OTHER hard line that has the orifice tube and filter in it, to ensure the filter isn't somehow clogged with debris. You *should* replace the drier cannister as well, but I have had good luck retaining that if the system isn't opened for more than a short time and then vacuumed for at least 30 minutes after installing the new hoses.

That is part of the job where you will need the right gauges and the vacuum, so it will be cheaper to have an actual shop pull it down and refill for you after the parts are swapped.

Jpd686 · **Joined:** Tue May 30, 2017 12:14 pm **Posts:** 50

geordi wrote:

Sounds like you have developed a leak on the high side that only presents itself when the system is running - high pressure is north of 150 psi in a properly running system, and it wouldn't take much of a leak to bleed out the system. If you can hear it though, that is a significant leak.

You can do two things at this point - Put in a can of gas with dye, knowing that you will be leaking down. If the pressure is only at 35psi when the system is off, either your gauge does not have a good connection to the schrader valve (it happens, some are deeper than others) or the system is just really low. Static pressure when the compressor is off should be around 90-100 psi depending on temperature. Since the AC system is sealed, the humidity outside doesn't matter to the pressure readings - it either has pressure or ti doesn't, and hot temps raise the high-side pressure because the compression can't shed the heat (in the condenser) as easily.

When a system with dye leaks, the dye will come out and glow when under a UV light, it will make the leak pretty easy to locate. It may be helpful to look for the dye at night or in a dark garage if that is an option - seeing it during the day will be difficult.

The other thing you can do is replace the high pressure hoses. I had a leak on one CRD that was from where the high pressure hard line bolted to the compressor on the driver's side (one bolt and an o-ring seal) because the aluminum manifold (little block of aluminum) that the hose ended at... Was just PRESSED onto the hose during manufacturing and it started to move and worked itself to a leak. Not a great design for the connection... But hey, it was cheap for Chrysler. That hose crosses the top of the radiator and bolts to the AC condenser at the front passenger side of the condenser. Not hard to replace, but the system will need to be vacuumed down and refilled completely when you do that. If you are going that far, you might as well replace the OTHER hard line that has the orifice tube and filter in it, to ensure the filter isn't somehow clogged with debris. You *should* replace the drier cannister as well, but I have had good luck retaining that if the system isn't opened for more than a short time and then vacuumed for at least 30 minutes after installing the new hoses.

That is part of the job where you will need the right gauges and the vacuum, so it will be cheaper to have an actual shop pull it down and refill for you after the parts are swapped.

ok thank you, my only concern is that the high side filling nozzle, is bigger than the low side so im not actually able to check the pressure, maybe it was just an optical illusion cause i didnt actually try to attach it, just looked at it and noticed it looked bigger. So i dont know how im supposed to fill it with dye if i dont have the correct fitting that came with the kit. or can i just put it on the low side and the dye will transfer over to the high side?

Jpd686 · **Joined:** Tue May 30, 2017 12:14 pm **Posts:** 50

Also I have not checked high side pressure as per reason stated above.

mrhemi · **Joined:** Tue Dec 08, 2015 10:46 am **Posts:** 180

You can only fill from the low side. That is why the fittings are different sizes. Sounds like you have determined that there is a leak, possibly on the high side. So, unless you are well versed in HVAC repair and have the proper tools available, you are on your way to an A/C shop at this point.

geordi · **Posted:** Wed Jun 28, 2017 11:32 am

Jpd686 wrote:

Also I have not checked high side pressure as per reason stated above.

The high side is a different size valve, this is intentional. The correct set of gauges have three hoses - one for the high side, one for the low, and one for the can / vacuum machine. It does seem like you may be best served having an AC shop assist you at this point, and they will definitely be cheaper than trying to buy all the equipment and teach yourself AC work.

You can go in with a reasonably accurate diagnosis right now that will save you a couple hours of shop time, because from what you describe and my experience with these CRDs, the most likely source of a leak is the high pressure line from the compressor to the condenser. It is the long one that crosses the front of the engine and bolts in just behind the grille. Easy to replace, and the failure point that I have seen is a manufacturing defect that fails over time.

They will likely want to replace the drier, but you should not need to flush the system (not a mechanical failure or a completely vented system) and replacing just the hoses / hard lines (they come complete and ready to install) doesn't take long or cost too much.

Jpd686 · **Joined:** Tue May 30, 2017 12:14 pm **Posts:** 50

Ok I will find the leak and fix it then take it to a shop to get it refilled thanks for all the help and I will notify when I find the problem and get it working!

Napheus · **Joined:** Fri Aug 25, 2006 5:39 pm **Posts:** 57

I've been here long enough to know that sometimes we assume the worst (read expensive and time consuming due to troubleshooting worst case scenarios) when it comes to repairs. Sort of like one electrician we have at work. Me, "Hey, this bulb is burned out." Electrician, "We better re-wire this entire circuit to make sure." While he is very thorough, sometimes more is not always better or needed.

This incident happened to me about 2 weeks ago. AC has always been cold since new, then one day after work, nothing. I initially went right to Freon leak as well because that's what we do, assume the worst. There was no way the system went from cold to having a massive leak basically overnight. Although this was a 3.7, I watched this video https://www.youtube.com/watch?v=WDJYsEzoYCY, and after testing, found my switch was also bad. It was $19.70 with tax at my local Car Quest, but Rock auto has them for like $11 or so. Easy change, I think it was 5/8", I used a crowfoot wrench without a ratchet or extension due to the location and tightened using my thumb until snug. One of the easiest and cheapest repairs I have ever made on this vehicle for a nice change of pace. Cold as it ever was, no charging required. Of course your mileage may vary.

EDIT- I want to add that my compressor was coming on for only a second or two and shutting off as well.

papaindigo · **Posted:** Sat Jul 01, 2017 5:10 pm

"There was no way the system went from cold to having a massive leak basically overnight". I'll rain on that parade a bit with a not CRD AC leak story IIRC in my first Dodge D250 Cummins. Driving down the road with AC cooling full blast; massive white fog from under hood; AC instantly stopped cooling. Aluminum bend in the AC line fractured and dumped all the Freon essentially instantly.

Glad yours was just the switch.

Napheus · **Joined:** Fri Aug 25, 2006 5:39 pm **Posts:** 57

papaindigo wrote:

"There was no way the system went from cold to having a massive leak basically overnight". I'll rain on that parade a bit with a not CRD AC leak story IIRC in my first Dodge D250 Cummins. Driving down the road with AC cooling full blast; massive white fog from under hood; AC instantly stopped cooling. Aluminum bend in the AC line fractured and dumped all the Freon essentially instantly.

Glad yours was just the switch.

And that massive white fog followed by finding the bent aluminum AC line was fairly easy to diagnose right? I don't think we are comparing apples to apples in your situation because you knew there was a catastrophic failure. It was mentioned earlier in this thread how a bad switch can mimic a low Freon situation. This was the first time I had ever experienced a system working fine one day and basically dead, literally the next day. There was no gradual loss of cooling as the Freon escaped and the system lost charge.

Most of my vehicles have been used, and some might say used up to some extent. In my extensive vehicle ownership history (24 and counting), air conditioning issues have usually been leaks. Either no pressure left in the system when bumping the low side Schrader valve, or able to charge the system and operate until the Freon leaked off again. Usually a week or less time.

This is my first Jeep. I knew what I was getting into when I bought it. The whole "I am my own warranty" thing still resonates 11 years later. (Went to finally change my thermostat on Tuesday only to find my turbo is now on the way out. Unplanned additional Jeep project for 2017 here I come.) I'd test the switch on any Jeep first from this point forward because this vehicle, at least mine for some reason, has a penchant for going through switches and sensors, suddenly and without warning, unlike any other vehicle I have ever owned. If checking that switch first saves someone that reads this thread time, effort and money in the future, then it has served its purpose.

geordi · **Posted:** Sat Jul 01, 2017 10:41 pm

How did you determine that your turbo is "on the way out" exactly? Oil in the mouth of the turbo means exactly NOTHING as that is completely normal and comes from the CCV. It is a symptom of the emissions control system design.

Napheus · **Joined:** Fri Aug 25, 2006 5:39 pm **Posts:** 57

When I did the timing belt a few years ago there was no discernible play in the impeller. Now there is movement in the impeller. Not as bad as I have seen from some of the videos online, but noticeable. Just went over 130,000 miles.

geordi · **Posted:** Sun Jul 02, 2017 12:43 pm

side to side or front to back? Front to back is normal, there is a little bit of movement along the axis of the center shaft. Side to side should be barely discernable.

Napheus · **Joined:** Fri Aug 25, 2006 5:39 pm **Posts:** 57

Up and down, side to side, take your pick. There was no movement when I did the timing belt. I was shocked at how much movement there is now. Enough movement to know it shouldn't be moving that much and it's days are numbered before bad things happen.

WolverineFW · **Posted:** Sun Jul 02, 2017 3:17 pm

tjkj2002 wrote:

R134A AC systems are filled by specific weight,not pressure.If you don't know how much is in the system you can't possibly now how much to put in.

This is essentially correct. Especially on automotive AC, since it is the easiest and most reliable way to ensure the correct charge on a critically charged system.

tjkj2002 wrote:

R134A is nothing like R12,freon is a dupont trademark name for there R12 by the way.

You have to watch this now. Chemours, who owns the trademark to Freon, is now slapping this term on multiple refrigerants, including R-134a, just to confuse then situation.

tjkj2002 wrote:

R134A will leak out at about 0.25 oz per year on a 100% sealed(IE no leaks) system since R134A molecules are much smaller then R12's and will bleed through the rubber hoses,no way to stop that.By the way all newer vehicles(last 20 or so years) have come with UV dye in the AC systems from the factory already since the high fail rate of R134A systems.

Correct. The hoses do have a known leak rate. Different depending on the the hose but your figure is a good average. It will take years to loose you charge that way normally.

Also compressor seals used to dry out and leak from lack of use over the winter. Since auto manufacturers were also trying to dehumidify when using defrost on the windows in the winter, they tied the AC operation to the defrost function, preventing most seal leaks now.

tjkj2002 wrote:

Plus most of those "DIY" kits at parts stores have stop leak in them and you do not want that stuff in your AC system,that is a $2000-$3000 repair bill since the entire AC system has to be replaced when you add that junk into it.

100 percent right That stuff is crap. Anyone who has had to change a plugged metering device on an automotive AC knows what a pain in the booty it is and the amount of hours it takes.

tjkj2002 wrote:

Without the proper tools and training you will do more harm then good.Just adding some R134A in is the worst idea ever and you need to know more then just the low pressure sides psi to actually figure out what's going on in the system,not to mention there are simple tests to determine if it's a electrical issue,mechanical issue,or a leak(low R134A).

Yes. Biggest problem with Auto AC systems is the environmental conditions can quickly change and the compressor capacity changes with RPM. You really have to understand how everything works together to determine how well it is operating.

This is why, as mentioned, weighing in the charge is the fastest and most reliable method. It also ensures if there is another problem, that the technician has now eliminated incorrect charge from the equation.

Sure, someone who understands basic electrical can fix minor problems, but AC is not for the average DIY.

I work on AC and refrigeration units, big and small everyday. You should see some of the stuff I have had to fix by people that were in over their head.

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WolverineFW · **Posted:** Sun Jul 02, 2017 3:28 pm

Jpd686 wrote:

https://m.canadiantire.ca/products/productDetail/0146129P/false/false/false?selectedSku=0146129

Will this product work?? Says for 134 and for 12 systems....?

I wouldn't put that crap in my AC. Get some actual R-134a if you are going to do it.

Adding that on top of 134a has now created a new unknown blend of refrigerant in your system with an unknown pressure temperature relationship. If it has to go into a shop for AC work, they will need to recharge it properly to do any proper troubleshooting.

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WolverineFW · **Posted:** Sun Jul 02, 2017 3:31 pm

geordi wrote:

Yes, that should work fine to check the pressure, and that kind of gauge / can tap will also allow you to use any can of gas, not just the one / two that it comes with.

You may need to have the can on the tap (with the needle fully retracted) just to act as a seal on that end of the hose. There should be a one-way valve in the adapter, but just in case. The filling is not quite as precise as someone above likes to say it is - he works for a chain place that loses money when people DIY. Measuring the pressure from both the high and low sides is the precise way to know it is full and working properly if you aren't fully evacuating the system, but the high side also varies with outside temperature, so you CAN properly gauge the fill with only the low side number that this gauge will give you.

Also - the system has both a high pressure and a low pressure cut-out for protection, so you aren't going to do much of anything other than waste some cash if you screw it up somehow. But this is an easy fix. Once you know the pressure, I'm sure you will find that with the compressor on, the low side is somewhere around 0-15 psi, which is give-or-take about a 12 ounce can low. You can look at the sticker on the front crossmember to know for certain, but I believe the "full" charge of this vehicle is 1.5 lbs, or 24 ounces. Just look at the specific can contents, you want only Tetrafluoroethane (the refrigerant) in whatever number of ounces the can says it is - no oil, no leak stop. You CAN GET cans that are only refrigerant - I'm also partial to the "Arctic Freeze" line of products by Interdynamics. Here in Florida, whatever blend they are using in this can does seem to provide better performance than regular 134a, which is itself a blend of chemicals.

https://shop.advanceautoparts.com/p/interdynamics-arctic-freeze-ultra-synthetic-r-134a-refrigerant-19-oz.-af-6/10055040-P?navigationPath=L1*14922%7CL2*15020

You really have very little idea about what you are talking about here. So much misinformation.

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WolverineFW · **Posted:** Sun Jul 02, 2017 3:32 pm

tjkj2002 wrote:

geordi wrote:

The filling is not quite as precise as someone above likes to say it is - he works for a chain place that loses money when people DIY. Measuring the pressure from both the high and low sides is the precise way to know it is full and working properly if you aren't fully evacuating the system, but the high side also varies with outside temperature, so you CAN properly gauge the fill with only the low side number that this gauge will give you.

Actually I make huge $$$ from DIY'ers,when it all goes wrong which is most of the time.

You can't judge a properly filled system by the pressures,to many variables(altitude,ambient temp,and humidity just to start) can effect those #'s,and sometime pretty drastically not to mention a compressor going or a partially plugged orifice tube can throw those #'s way off but still work enough to produce cool air.At that point where the AC works "well enough" can cause other issues like evap core freezing.Overfilling greatly increases the chance to blow the compressor apart(seen this more times then I can count).

As little as 2-3oz can make a AC system not work properly,depending on system size, and there is no way to to know how much is in the system already without evacuating the system and weighing what came out.

Again the system is not filled by pressures but by weight.

Yes.

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Jpd686 · **Joined:** Tue May 30, 2017 12:14 pm **Posts:** 50

Just want to add that my ac is working.... I went and got some freon with dye in it and topped it up to get the dye in there, and it has started working. Have not found any obvious leaks since putting in the dye ( checked with UV light) seems to be working and blowing ice cold now!

no more hot rides stuck in traffic haha

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