A/C pressures

[mikkelstuff]

Probably here somewhere on the site but my 2002 Ranger A/C needs refrigerant and I would like to know the desired low and high side pressures.

 

[97RangerXLT]

That is a very dependent on the outside temp number. There should be a sticker on the radiator support that tells you how much in ounces R234a needs to be in the system. That amount will give you what you need pressurewise and cooling wise assuming your a/c is working correctly.

You have a leak somewhere so in that instance. It is not working correctly and the right way is to evacuate your system and put in the correct amount of refrigerant wit leak detector dye and go from there.

To do a do it yourself. You need a manifold gage set to get both high and low side pressure, an accurate thermometer, measure the outside temp, get humidity level as well and find a temperature/ pressure chart for R134a on the web and pay attention to your gages

Do not just chuck a can in or use only the low side pressure...

AJ

 

[1990RangerinSK]

Probably here somewhere on the site but my 2002 Ranger A/C needs refrigerant and I would like to know the desired low and high side pressures.

Low side pressure: Lower than the high side.
High side pressure: Higher than the low side.

 

[Vindictus]

this is a good read on a/c system https://www.therangerstation.com/tech_library/Resurrecting_Your_Ford_Ranger_Air_Conditioning.shtml

 

[97RangerXLT]

this is a good read on a/c system https://www.therangerstation.com/tech_library/Resurrecting_Your_Ford_Ranger_Air_Conditioning.shtml

Was going to dig that out, then I saw Squirrels and just now remembered it.... if my brain were a computer, it's name would be 80-HD

AJ

 

[mikkelstuff]

Checked the pressures today. 100 psi on the high side and 100 psi on the low side. So how is this?

The A/C does cool but off for a time and then on for a time including the air flow out the vents. I assume the evaporator is freezing up.

 

[1990RangerinSK]

Was going to dig that out, then I saw Squirrels and just now remembered it.... if my brain were a computer, it's name would be 80-HD

AJ

More likely, it's name would be dog. And yours might be Fido, rather than Guido (AKA mob boss).

 

[97RangerXLT]

Checked the pressures today. 100 psi on the high side and 100 psi on the low side. So how is this?

The A/C does cool but off for a time and then on for a time including the air flow out the vents. I assume the evaporator is freezing up.

generally if you have poor cooling, similar pressure on high and low side, and the compressor is in fact engaging and turning, it means your compressor is worn out. (not compressing) if you are going to replace the compressor, just bite the bullet and replace everything. and I mean everything. condenser, evaporator, lines, orifice tube, accumulator... If refrigerant touched it, replace it. you will spend a serious amount of time flushing the condenser and evaporator, and will not get them 100 percent flushed, and they will likely leak. (see my how too above) I decided not to replace the evap and it failed a year later after replacing all the other crap.

AJ

 

[sgtsandman]

In the Honda CR-V world, the 2002-2005 CR-Vs had issues with the compressors genading internally and replacing the entire system was exactly what they had to do. Otherwise, any remaining contamination in the system would cause the new compressor to fail.

AC systems have to be absolutely clean, at least on Hondas.

 

[97RangerXLT]

In the Honda CR-V world, the 2002-2005 CR-Vs had issues with the compressors genading internally and replacing the entire system was exactly what they had to do. Otherwise, any remaining contamination in the system would cause the new compressor to fail.

AC systems have to be absolutely clean, at least on Hondas.

this is exactly why I say replace it all. at the very least if you do not replace the condenser or evaporator, you must flush them. and most modern cars these components are made in such a way that it is impossible to get all of the debris out. In my Ranger's case, the original compressor did not fail, it was a leak in one of the fittings, so I tried my luck and flushed it. worked ok until the evap leaked the refrigerant out the following year.

Most new compressor warranties will be void if you do not buy a new orifice tube, accumulator/ dryer and either a flush kit or new condensor. in the end, just get all of the components. save the agravation.

AJ

 

[black_demon69]

What they said

 

[mikkelstuff]

I had the shop check and refill the A/C system. All cools well EXCEPT the cab air flow is very sensitive to vacuum conditions.

Also, when I started the truck this morning I got no airflow out of the vents. Then suddenly I got full cold air flow. So why is this?

 

[mikkelstuff]

Ok, found the answer - I think. The default air flow is out the defroster vents - which is what I have. Looking through my manuals I found the vacuum reservoir under the intake air filter which I will now replace.