A/C Fixed - NOT!!! (Long, sorry)

[Geo-TH,In]

My JD 4255 AC has cooled very good in Texas weather with the manual heater hose cut-off valve I installed over 30 yrs ago closed very tight. I'm curious did dealer service manager get Kelley's pre-approval to perform a $5,768.57 AC repair?

Tx
Sometimes Redneck DIY engineering works best and much cheaper.
Bigger question, what is Kelly going to pay to fix it a second time?

 

[rustred]

what did they find and what parts where replaced ? lots of money to remove and replace panels. but anyhow how are you running it ? there is a thermostat for temp setting , where are u running that ? i think you are freezing up. run the thermostat on 68-70 degree's and see what happens, plus run the fan on high or fast, not on slow. running the setting on max cold is not the best thing to do, as the compressor wont cut out. u can experiment yourself to find out whats going on. put a thermometer in the vent and see what temperature you have there. should be around 30-32 degree's. just a couple of pointers. you need qualified personal with the guages to see whats going on.

 

[Tx Jim]

Tx
Sometimes Redneck DIY engineering works best and much cheaper.
Bigger question, what is Kelly going to pay to fix it a second time?

If it was my tractor that stealership would get my tractor blowing cold air for $00 or get to know my attorney very well!

 

[bc]

I'm guessing that you are dealing with very high humidity down there which exacerbates the problem. But it is always high down there. There is a high pressure system moving over Texas so no relief for a while with the temps either.

I'd like to see pics of the repair bill to see what was replaced. They should have replaced all the lines and other parts for that price. Also you may have been charged the higher of the hours listed in the shop manual or what some first time new guy put in. Auto repair and body shops price hours according to the manuals. Then the experienced guys do it in half the time and the shop makes more money. Or else they take shortcuts to save time.

Still need to let them know immediately and be prepared for a return trip while their repair has a short warranty on it. They may have a suggestion to fix it or more likely come up with an excuse.

 

[jimg.allentown]

A few things to consider about your A/C:
>Water freezes at 32 degrees Fahrenheit. We all knew that,but we seem to forget it when it involves A/C. First thing to know is the temperature at your evaporator core. Anything below ambient (correction - Dewpoint) can result in condensation on the core. If the temperature falls below 33 degrees, the evaporator begins to freeze that condensation.
> Drainage is important. It the condensation does not drain properly, it can build up and lead to freezing onto the core IF the temperature of the core falls below 33 degrees F.
>Overcharged system will not cool well. It may cool some, but does not complete the change of state at the right place or to the required level to accomplish heat transfer. Yep, that is what makes the entire system work. By the way, that also includes too much OIL in the system. The oil circulates through the system along with the refrigerant to lube the compressor.
>Undercharged system will also not cool well. Refrigerant evaporates right at the metering device causing freezing.
>Every A/C system has a metering device . Some use a fixed orifice. Some use an expansion valve. Others (older ones) may use a POA valve or even an EPR valve, but ALL systems have to have a metering device to function.
>Moisture in the system. Most systems do not like moisture in the system. It can freeze the metering orifice (that is the coldest place in the system) and cause the system to stop functioning. That is the reason for pulling a strong vacuum before recharging - to "boil off" any moisture in the system.
>Air in the system. Air is a non-condensible gas in A/C terms. In order for a system to function, two basic principles allow heat transfer. Gas being condensed into a liquid gives off heat. Lots of heat. Liquid evaporating (changing state back to a gas) will absorb heat. That is what makes the evaporator core colder than ambient. It is absorbing heat from its surroundings.
> Gauge readings alone do NOT directly transfer to temperature readings. That requires the use of a thermometer in conjunction with a charging chart to see if the system is operating properly.
>Freon is a DuPont trademarked name that refers to an entier family of materials. Not all Freons are refrigerants, and not all refrigerants are Freons.
>Lastly, I sincerely hope this will be of some help. I do NOT know what is wrong with your system without rolling up my sleeves, p[tting gauges on it and making temperature measurements - nor does anybody else here for the same reason.