WhHaShat psi should my ac be on my dakota
- Thread starter aarong5
- Start date
-
Mopar to ya
Well-Known Member
You have two pressures to be concerned with, high side and low side. On top of that, ambient air temperature affects pressures as well. How are you checking the pressure? If you only have a low side reading I assume you have a cheaper parts store assembly ... the kind that scare the crap out of me. I would get or borrow a gauge set, or take it to a shop. That said, if 35 is the correct reading on the low side, that would be a bit low. The trouble is, you don't know how low without recovering and weighing what you have in there. Adding blindly is a hit or miss proposition. Overfilling can cause warmer temps as well. Having done this for a lot of years, I highly recommend a proper a/c check. Add dye, look for leaks, evacuate system an make sure it holds vacuum, and if so add the proper amount of R134A. It is not as expensive as it sounds and you will know if you have any leaks (especially since the evap cores are notorious for slow leaks on these vehicles) and it will be filled and properly functioning when done. Plus if it has a leak later, it will have UV dye in it and it will be easier to trace the leak.
Mopar to ya
Well-Known Member
I almost forgot - we have a lot of cottonwood trees around here. In the spring we get so many plugged or restricted condensors it isn't even funny. Look between the radiator and the condensor and see if it looks restricted with debris. If so, use a hose or air and blow the crap from the inside out. Restrictions cause higher high side pressures resulting in slower cooling and higher vent temperatures.
Right on Mopar to ya! Damn cottonwood trees!
67Dart273
Well-Known Member
Pressures don't tell you squat if you don't know a few other things.
If the cabin is really warm, the low side will be higher than it should be, even though it's undercharged.
If it's a "not real hot day," you are doing this in the shade, on "max air" and the cabin gets down fairly cold in temperature, the low side can fool you by reading LOWER that it might, even though it might be OVERcharged. Another thing that can artificially lower suction readings is if the inside fan is running slow, dragging, or plugged, or have some other restriction like heater control door problems.
If the condenser is not getting enough air, due to dirt/ plugged, defective fan, sitting in a restrictive shop, etc etc, THAT will screw up your readings.
If the cabin is really warm, the low side will be higher than it should be, even though it's undercharged.
If it's a "not real hot day," you are doing this in the shade, on "max air" and the cabin gets down fairly cold in temperature, the low side can fool you by reading LOWER that it might, even though it might be OVERcharged. Another thing that can artificially lower suction readings is if the inside fan is running slow, dragging, or plugged, or have some other restriction like heater control door problems.
If the condenser is not getting enough air, due to dirt/ plugged, defective fan, sitting in a restrictive shop, etc etc, THAT will screw up your readings.
Mopar to ya
Well-Known Member
Sorry, but pressure tells you everything. Without that, you have no basis to begin anywhere. Some people like to shotgun a guess and throw parts at a car to try to repair it. Where I come from we diagnose it properly and repair what is needed. Pressures will show you if your condensor is plugged due to higher high side pressure. Good pressures tell you the system is operating and to look elsewhere, like stuck mode doors, etc. Also, you need to take ambient air pressure into account for pressure readings as well. And the differential between low and high pressure is critical. Every good, qualified and intelligent tech will start with pressure readings. I am not saying that is the only place to look, but if you look at the post, the original question is about what pressures should be. And it is always the key starting point. It has been since I began working on R12 A/C 30 years ago, and still is in R134a systems. At least that's what they told me when I re-qualified for my ASE heating and air conditioning test.
67Dart273
Well-Known Member
I guess you didn't actually READ what I posted. Pressures do NOT tell you everything, unless you know "some other stuff" just as I posted.
'S why we have these other things called thermometers, n' stuff
OR Maybe you mis- understood my meaning? I thought I explained it. What I meant was that JUST pressure readings ONLY pressure readings, Using NOTHING BUT pressure readings does not give you all the answers.
Please read my post again
Mopar to ya
Well-Known Member
I did read it. I didn't mis-understand it. I can't understand why you would consider doing anything other than determining if the system is capable of working first.
TylerW
Well-Known Member
Because he's trying to answer questions like SlantsixDan, because he doesn't care for Dan knowing so much.
But...he's not Dan
-
