Q: Air conditioning pressure doesn't change when clutch is engaged.

asked by on October 20, 2016

Recently had an AC Line (High Side) blow, assumed it was just an old line. Replaced the line, the drier and did an full evac and started to put fluid back in with a gauge set. Once the clutched engaged the pressures didn't change at all, so I figured the compressor had to be bad. Replaced the compressor (reman) and did another evac and started to put fluid in again and once again, once the clutch engaged the pressures don't change at all. So is it just another compressor that is faulty? Can't really think of what else it would be, I would think even if it was the expansion valve that faulted that pressures would still change. Any help would be much appreciated! :)

P.S. I've done my own AC a few times already and done AC on other vehicles before without problem.

If your expansion valve was stuck in the open position then you may not see much, if any, change in pressures. Before replacing the expansion valve I would recommend you remove the compressor inlet line and turn the compressor by hand to see if you feel it sucking in the line you disconnected. If you do not feel any suction then you have a compressor that is bad. If you feel a good suction then replace the expansion valve, evacuate, and recharge. Then retest system to see if it works normal. To avoid any unnecessary repairs, consider YourMechanic, as one of our mobile technicians can come to your home or office to diagnose the issue with your A/C and help you fix it accordingly.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing


Experienced Mechanic?

Earn up to $70/hr

What others are asking

How do I quickly heat the cabin of the vehicle?
If it is cold inside your car’s cabin, you can use the climate controls to quickly heat up the car. To heat the cabin quickly, follow these quick steps: 1. Use the fan control dial to set the fan speed...
Overheating problems
Hi. Overheating is typically caused by three main concerns, either not enough coolant in the engine, not enough flow of coolant, (stuck closed thermostat, pinched hose) or the radiator isn't exchanging heat fast enough. If the coolant level looks ok...
Undriven car's battery started, but ran rough
Hello there, When vehicles sit for long periods of time like this a few things can happen. The battery can drain (https://www.yourmechanic.com/article/symptoms-of-a-bad-or-failing-battery), the fuel can lose its octane rating, and oil can pool in the cylinders. If the vehicle is...
Problems after thermostat, digital cluster & cooling pump replacements
It appears you may have a few different issues going on. It seems unlikely that more than one cluster would fail. The most likely cause is a shorted wiring or open circuit causing the clusters to fail. If the car...
After sensor replacement, 2nd diagnostic revealed P0139
No, it is not the catalyst. The P0139 code (https://www.yourmechanic.com/article/p0139-obd-ii-trouble-code-o2-sensor-circuit-slow-response-bank-1-sensor-2) is for the O2 sensor before the catalyst. The code is illuminated when the engine control module is testing the O2 sensor and it cuts the fuel to see if...
Engine is running horrible with stalling and noises under load.
Hi and thanks for contacting Your Mechanic. As for the engine misfiring and having an issue with the rough idle (https://www.yourmechanic.com/services/car-idle-is-rough-inspection), there could be a vacuum leak on the engine. Check all of the vacuum hoses and the intake to...
My 2009 Dodge Ram Hemi 2500 makes a loud rumbling noise in the front end. I stop giving it gas couple times and it goes away
Hello, thank you for writing in. The noise may be coming from a number of issues with the vehicle. Considering the loss of power, you want to focus on the exhaust, air intake, and spark systems. An exhaust leak or...
Knock sensor for 2002 chevy avalanche
Hi There, As you know, code P0332 relates to the knock sensor, which may be a result of code P0306, which relates to the crankshaft position sensor. When the crankshaft position sensor (https://www.yourmechanic.com/services/crankshaft-position-sensor-replacement) is detected to have more than a...
I have a vitz 2003 FL 1.3 automatic it jerks at slow speeds and low revs around 10 - 50 kmh . Also sometimes the gear gets stuck
With a high mileage car like yours, the first thing I think about is whether the scheduled services have been performed. Spark plugs and filters last pretty long, but they should have been changed at least once in your car....

Related articles

The Best Used Cars to Buy If You're an Archeologist
If If you are an archaeologist, you need a vehicle that will take you off the beaten path. After all, that’s where you spend a good deal of your time. And that means that you will need, ideally, an SUV...
Symptoms of a Bad or Failing AC Clutch Cycling Switch
If your AC is not blowing air as cool as usual or is not working at all, you may need to replace your AC clutch cycling switch.
How Long Does a Heater Blower Motor Last?
During During the colder parts of the month, you will start to rely more and more on your car’s heater. With all of the different components that are in place to ensure your heater works correctly, you may have a...