air conditioning

[joshtypesn]

I need help...I just replaced all of my AC components and the air was fine for a while, not cold, but OK. Recently the air stopped working so I put my gauges on and found a reading of 40 on the low side and over 400 on the high side. What could this be? The compressor is still running

 

[my98nnj]

Sounds like an over charge. Did you evacuate the system before you put R134 back in?

 

[BrianDye]

I'm having a simaler issue on my 92, charged it up, GREAT ice cold air for a month then it's just like room temp now, pressure it a TAD high where you put the refridgerant in, never checked anything else though so hopefully this thread could help me too lol

 

[joshtypesn]

Not over charged as when i first vacuumed and charged I only put it to 35 on low side and 220 on the high...so unless someone snuck another can or two in when i wasn't looking then the charges were originally fine

 

[joshtypesn]

any other ideas??

 

[gijoecam]

Clogged orfice? That's my best guess...

 

[ranger7ltr]

Conditions on day of initial charge?

What was the air temperature on the day you charged the system and how low did the system vacuum down before charging? And what was the air temperature when you measured the charge in the system?

How did you measure the weight of the refrigerant charge or did you use individual cans to charge up?

What components did you replace?

And how is the fan clutch/radiator/condensor? How clean are they and how old is the fan clutch?

Your readings on the initial charge sould ok if the air temperature was around 100 F...If the air temperature was lower then less refrigerant needed to be installed...Plus I hope that if you used cans to charge the system you purged the fill line before restarting with a new can or you might have air in the system...

And clooged orifice tube, like Gijoecam stated, or condensor is not out of the realm of possibility...

One other reason for the higher readings though can be that the fan clutch is not pulling enough air to cool the condensor and use of the system elevates the pressures...

When you initially charged the system you stated it cooled but not was not cold...What were your vent temps and in what a/c position?

 

[RickMar]

Check this automotive A/C forum out.
It is loaded with A/C guru's.
Just join then post a question

http://www.autoacforum.com/index.cfm?NoCookies=Yes

Rick

 

[joshtypesn]

Thanks for the replies... To answer your questions ranger when I charged the system it was probably about 90 outside but in the garage maybe about 85. I did charge by cans and filled according to the amount of ounces recommended my the Haynes and some places on hear. I vacuumed for about 15 to 20 minutes and actually left the system vacuumed for a few days because I was missing an adapter for my can tap, I left at about 30 inches of vacuum. I replaced all the components (condenser, compressor, accumulator, and evaporator, also the main AC line, oraphis, and all o rings) I DID NOT change the pressure cut off or compressor cycling switch, nor did I change the small line from the evaporator to the condenser. All lines were flushed and oiled. The radiator is fine I flushed it a few months ago and also cleaned and brushed the fins. The condenser as I stated is brand new. The fan clutch and fans seems to be fine, although I am not sure how I would determine that. When I charged the system the temps were average around 60 to 70, there would be spurts of ice cold air but mostly marginal air all the time, this was on MAC AC full fan, any slower and it was still hot in the car. I appreciate the help greatly and will also check out that AC forum rickmar. Thanks

 

[TheJackal]

It does seem like something is plugging up the system...

What kind of oil did you use in the system? How much did you put in?

You should use PAG 46 oil for our systems.

 

[rhauf]

if there is a filter (usually right after the compressor) it could be clogged. check to see if the accumulator is cold on one end and warm on the other, if so it could be bad (so ive heard) and as stated, could be the orifice valve.

 

[ranger7ltr]

I don't think you are overcharged...

Thanks for the replies... To answer your questions ranger when I charged the system it was probably about 90 outside but in the garage maybe about 85. I did charge by cans and filled according to the amount of ounces recommended my the Haynes and some places on hear. I vacuumed for about 15 to 20 minutes and actually left the system vacuumed for a few days because I was missing an adapter for my can tap, I left at about 30 inches of vacuum. I replaced all the components (condenser, compressor, accumulator, and evaporator, also the main AC line, oraphis, and all o rings) I DID NOT change the pressure cut off or compressor cycling switch, nor did I change the small line from the evaporator to the condenser. All lines were flushed and oiled. The radiator is fine I flushed it a few months ago and also cleaned and brushed the fins. The condenser as I stated is brand new. The fan clutch and fans seems to be fine, although I am not sure how I would determine that. When I charged the system the temps were average around 60 to 70, there would be spurts of ice cold air but mostly marginal air all the time, this was on MAC AC full fan, any slower and it was still hot in the car. I appreciate the help greatly and will also check out that AC forum rickmar. Thanks

Based on your information, if the ambient temp was 90 F, the pressures read should have been 207-243 psi on the high side...Ambient air temp x 2.3/2.7=high side pressures...

And if the system vacuumed down to 30 inches in 20 minutes that is great...Here in Texas I usually vacuum for an hour AFTER checking the system for sealing when it has run for 30 mins or so...That is to remove all traces of air/moisture in the system...Dropping to 30 inches is great but the moisture needs to be goiled out of the system to make sure it is absolutely dry when you charge it...When you were vacuuming the system down was the pump making gurgling noises or was smoke/steam coming out of the pumps discharge port?

I only have a couple of suggestions here...

1a.Test the fan clutch by seeing if it turns more than one full revolution after the engine is up to temp and you turn off the engine...You should also hear a definite roar after running to nominal engine temp and you rev the engine to 2-3k... Do either with the hood up and watch from the drivers seat...

1b.Also with the hood up and the gauges attached, run some water through the condensor...If the high side dropped more than 100 psi, your cooling fan ain't getting the job done...You can also check the vent temps and see how much they drop with the water stream...If they drop 10-20 degrees the cooling fan and system is not doing its best...

The second is to going to be a bit harder...

First how much oil did you install in this system and when did you introduce oil into the sealed system? Also was the oil sealed up to the point you poured it into the various components? How long was the system open to the atmosphere after the oil was poured into the system? And was the feed line purged between cans of refrigerant?

The type of oil is important as well since R-134a cannot move mineral oil through the system so PAG is the most popular and some use a synthetic oil like Polyalpha-A but using an oil that has no moisture in it is even more important.. Oil will absorb air and moisture so its age and exposure to the atmosphere will determine how much and how long the system needs to vacuumed out...

I am really thinking your system has air in it and this would explain the high/low side pressures and the lack of cooling... As a reference, I see 36-43 F at the drivers center vent @ 103 F ambient and this was earlier this week...This is typical for my Explorer and my Charger as well...

And the a/c forum is a great resource for problems like this as well...

Good luck and let us know what you find...

 

[joshtypesn]

In regards to the oil, I used about 8 ounces of PAG 46 when i first installed the components, I added to each component about a third of a can (except the evaporator) When I charged the sealed system I ran a 3 oz can of PAG and refrigerant mix before the regular 134a.

In regards to the vacuum, I will admit i just used a venturi type pump off the air compressor so I let it go as long as it could but then just stopped it all when it was at its max, I did not hear it or see it purge any moisture.

I will do those tests with the fan and condenser tomorrow and get you guys the results. I will also let you guys know if i find anything out from AC forum. Thanks again for all the help.

 

[ranger7ltr]

I was hoping to not read that...

The venturi vacuum pumps are not useless...They are just not really good at removing moisture from the system...I have tried one and the air supply introduces moisture into the very system you need to remove air and moisture from...

And you got way too much oil in the system... 11 oz of oil is going to retain a lot of heat and moisture and the PAG oil will love to saturate itself with the moisture in the system...

How long has this system been together running this way? You might be able to purge the moisture with a good vacuum pump and a long deep vacuum but I would think any more than a few days and your new accumulator is probably has saturated dessicant at this point and vacuuming the system will not remove it...Neither will baking the accumulator in an oven although I know people that will do that to save buying another one...

Sorry to say this but I would evacuate the system, remove all the oil by flushing it, replace the accumulator, add the correct amount of oil back to the system[it can all go into the accumulator or half there and half in the condensor], use a borrowed micron vacuum pump and draw a deep vacuum on the system, then recharge by weight if possible or use cans to charge making sure to purge the supply from the can each time you tap a new one...

 

[joshtypesn]

I appreciate the help, even if it happens to be bad news for me. I was talking to a buddy of mine who also has an explorer (97) and we compared fans. We both seem to think that before I go any further with the AC that i need to get my fan up to speed as it seems very weak. I will most likely end up re charging the system anyway as I want to re flush and replace the oraphis to be safe. I will also replace the accumulator as you have mentioned. I do have thoughts of a possible weak compressor. I purchased an ebay compressor and figured that if I am going to end up replacing the accumulator, I might as well replace the compressor (what do you guys think?) I will keep you posted, I will do the hose test with the condenser tomorrow to confirm the fan is not pulling. Thanks for all the help, it is greatly appreciated. Also, what amount of oil do you recommend in the system? Anyone in Fort Myers area who has a vacuum pump I would be willing to pay for use of this and help when I get everything I need to get this going. Thanks again...

 

[ranger7ltr]

I think your compressor is fine...

Hell if you are seeing 400 psi on the high side that compressor is pumping just fine!!! I don't think you have any worries there...Now if you open the system and find any bits of teflon seal on the orifice tube that would have come from the compressor and then I would be concerned...

Is the compressor a new, remanufactured, or used unit? If you don't see any debris from the unit I would probably go back with it...

And Autozone has [or had the last time I needed] vacuum pumps on their rent-a-tool program...One thing I would do with any rented or loaned pump is to change the vacuum pump oil to ensure the oil in the pump is as clean and free of moisture as possible... I change my own pump oil every use to make damn sure I don't add air into the system I am trying to vacuum down...And a quart of pump oil is cheap...Less than 3 bucks and it lasts quite a while...

Once you get the air out of the system, get the right amount of oil in the system, and replace the fan clutch to make sure the right amount of air is going through the condensor you should see vent temps cold enough to make you turn it down...

If you need any more help let us know... and I wish I was closer than Texas...I like a good challenge like this...But it is usually the little things that cause us the most grief....Good luck man....

 

[joshtypesn]

Here is an update

I was running water on the condenser because I was pretty sure the fan was bad after comparing it to a friends and the fact that I realized that I never hear it anymore, even in over 100 here in Florida, so I am thinking my gauge is bad also in the dash...ANYWAY,

While doing so, my pressures were fine again, in fact they were a little low because I was purging it to see if I could knock debris loose. I was adding some 134 and the system would not take anymore (though the low side). I checked the vents and was getting decent air, not cold like I want, but maybe about 70. I had my wife try the hose on the condenser to see if I could get a lower temp, before we could really see any differences the compressor kicked off and so I looked at the gauges. Instead of the system balancing like it normally does, the high side was about 100 and the low side at about 190 or so, the gauges read this even after the engine was off.

From what I am experiencing it seems like there is definitely a blockage moving around in the system. First things for me are going to be to replace the fan clutch (unless you guys can sell me on an electric fan, I am just not sold yet) And following that it looks like I will be doing a flush, vacuum and re charge with a new accumulator just to be sure.

What are the opinions? Am I correct?