How To Check If Car Expansion Valve Is Still Working

Happy mechanic man with clipboard at car workshop

The car expansion valve is one of the parts of the A/C with different roles. One of those is to regulate the pressure drop of the refrigerant evaporation process and cold generation. Also, it regulates the rate at which the fluid flows in the evaporator. Moreover, it regulates the temperature to avoid overheating. 

The expansion valve takes in the refrigerant in the fluid state which after gets filtered. The valve will decrease the refrigerant pressure of the evaporator. Due to this pressure drop, the fluid gets sprayed into the evaporator.

There are several symptoms of your air conditioning system not working, and there may be several causes for it. However, in case of damage, the signs will not be late to pop in and ultimately stop the functioning of your A/C.

Check the Sensing Bulb

The sensing bulb, filled in with gas sensitive to temperature, is located at the bottom of the evaporator having the role to ensure whether enough refrigerant flows to cool the whole evaporator.

If you suspect a malfunction of the sensing bulb, the first thing you should do is to check whether it is firmly connected to the suction line or not. If the bulb is loosely stretched, then it is clear that this is a cause for underperforming. The air conditioning may start to perform poorly, or start to blow warm air in case of a more severe issue.

Verify if the Liquid Orifice Is Clogged

In cases of a clogged liquid orifice, the refrigerant may start flowing continuously through the A/C. Eventually, these will lead to a frozen evaporator. 

Also, as it gets clogged, the A/C will start to underperform up to 30%. Because it is not an easy job to determine whether the orifice is clogged or not, the best would be to contact a specialist that can make a professional assessment.

Turn On the AC and See if Warm Air Blows Out

One of the recurrent signs of an A/C expansion valve system not performing is associated with warm air blow. This may mean that the refrigerant does not arrive at the evaporator’s core. Specialists recommend having a check of the A/C before the summer months get you.

The AC Blows Out Cold and Warm Air Alternatively

If the air conditioning faces fluctuations between warm and cold air without the user’s intervention, this may be a sign of a faulty expansion valve. The role of the expansion valve is to remove pressure out of the refrigerant liquid. Further on, the evaporator allows the transformation from a liquid state to vapors. If the valve is obstructed, the refrigerant flow may fluctuate in different ways.

Having the summer days around the corner, it should be a sign for you to evaluate the A/C system and do maintenance or a repair if the car requires it. Contact one of our specialists from R & Y A/C Compressors® today and get your air conditioning evaluated.