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May have F'd up. Need advice on what to do next

jonnyz2 on Thu June 19, 2014 2:38 AM User is offline

Year: 2007
Make: Mazda
Model: 3
Engine Size: 2.3
Refrigerant Type: r134a
Ambient Temp: 83
Pressure Low: 30
Pressure High: 212
Country of Origin: United States

So, when I started this saga I followed the advice of my local parts store and the instructions on a "recharge kit" that included a can of refrigerant mixed with oil, a gauge, and a hose.

In mild temps the car was not cooling as well as it should; so, I went to the auto parts store and got a recharge can with built in gauge from a major mfg (AC (NOT) Pro). After 7+ years (car purchased summer 2006) this seemed reasonable.

Following the kit manufacturers directions led to initially better cooling but the gauge was showing lower low side pressure than they recommended. As I added more refrigerant the gauge did not change readings. At that point I assumed a faulty gauge and returned the combo to the store and got a new one from them. The second one did show different readings and did move higher as I added more to the system.

Cooling improved a bit more but still the system did not show the low side pressure recommended. As I added yet more refrigerant the system then stopped cooling all together.

At this point I assumed a second faulty gauge and that the system had been overcharged. With parts store assistance, removed some of the refrigerant from the system. Cooling resumed, but not as well as after just initially adding new refrigerant.

Several days later temps high 90's low 100s (f). In city driving the compressor seemed to shut off for long periods and the system would go from producing cold air to warm air. On highway driving the off periods were shorter and cold air more consistent. Assuming continued over pressure situation, more coolant was removed from the system.

Given the way the cans with built in hose/gauge work, besides likely overcharging the system I think it is also likely that some air was forced into the system. I also wonder about too much oil as the instructions recommended putting the can between upright and sideways while charging and I noticed that the fluid from the can was highly oily when some vented from an incorrect connection to the low side port.

I have now rented a manifold gauge and measured pressures. At 83 degrees F and low humidity the low side measured 30 and the high side 212 at idle. The high side was higher and low side a bit lower at 1500 rpm.

According to some of the high/low tables I've seen the low side seems to be too low and the high side is too high.

Based on everything I've read since starting this mess, I think I need to take it into a shop and have it fully evacuated and then refilled.

I do though read that it is better if the vacuum is left on the system for some time (e.g. overnight) in order to dry them out. Is that really true? Will most shops actually take that time or can I expect just a quick job and that part skipped?

Please advise me on the correct next steps for this situation. Is there anything that I should directly ask the shop to do or check at this point?

Is there likely an specific damage that all of this could have caused?

Finally, the other thing that would be helpful is to know whether it is ok the operate the AC at this point of would it be safer to service it first.


Edited: Thu June 19, 2014 at 11:39 AM by jonnyz2

Dougflas on Thu June 19, 2014 3:27 AM User is offline

Have the system evacuated and the correct amount of R134a installed. Then you know that the correct charge is in the system. Ask them to evacuate the system over night if possible. Mast shops can not afford the time to do a long evacuation during day time because of work load. Be patient and allow them the time. A 30 minute evacuation is standard but will not bring your system to 500 microns in most cases.

HECAT on Thu June 19, 2014 2:13 PM User is offline

For the benefit of others, yes you f'd up.

1. Followed the advice of the local parts store.
2. Used a recharge kit that contains who knows what.
3. Got another recharge kit when first one did not work.
4. With parts store assistance, vented some refrigerant.
5. Suspect over pressurizing, so vented more refrigerant.

The correct step would have been to ask here first; I sure wish you had. Please tell the shop exactly what you have done and show them the product you have introduced to the system. Yes, the reality is you may have ruined the entire system, and the shop may refuse to touch it. Run it, why not; I don't think you can do any more damage now.


HECAT: You support the Forum when you consider for your a/c parts.


jonnyz2 on Thu June 19, 2014 3:09 PM User is offline

Yep, began to learn what I needed to know when it was already too late.

Can't believe products are sold with instructions that are fundamentally not the right way to do things.

Got suckered!

HECAT on Fri June 20, 2014 9:39 AM User is offline

Believe it. Many products are sold today with the goal much less about how well it works, and much more about how much can they suck from your wallet. Unscrupulous, immoral, improper, but perfectly legal.


HECAT: You support the Forum when you consider for your a/c parts.


dinger on Mon June 23, 2014 4:40 PM User is offline

Don't use 'death kits' you could overpressure the system and a component could burst and take your eyes out, or worse.

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