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Best Auto Repair, Knoxville

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Replace Your Car's AC Thermal Expansion Valve or Orifice Tube

 95 Verified Review(s)

Your car or truck's AC system is under extreme pressure and the thermal expansion valve or orifice tube monitors the amount of pressure and the temperature of your A/C system. It calculates the precise amount of refrigerant that can safely go into the evaporator. A failing expansion valve or orifice tube often causes a vehicle's air conditioner to blow hot air.

Replace or Repair

  • Expansion Valves: Too much refrigerant causes your evaporator to get too cold whereas too little refrigerant would result in inadequate cooling. The expansion valve is a complex valve that regulates refrigerant flow. This process of metering the refrigerant adjusts the flow according to the temperature of the refrigerant in the evaporator coil. Talk to one of the pro mechanics at B & M Automotive & Diesel Service, as this part can be replaced on its own and does not require the entire replacement of the AC assembly.
  • Orifice Tubes: Unlike the expansion valve, the orifice tube is a simple fixed device with no moving parts. It therefore cannot vary the flow of refrigerant into the evaporator, but rather causes a permanent restriction in the system. However, like the expansion valve the orifice tube regulates refrigerant flow through the system and filters debris which may come through in its screen. Often fixing a "bad orifice tube" requires replacing the entire evaporator assembly.

More AC Repair Services:

Truck and Car AC Repair Services

Freon Recharging Services For Your Car Or Truck

AC Evaporator Services


what our customers say

I flip cars here and there and I take all mine to these guys at B & M. They are very thorough yet cost efficient. I'm very pleased with our relationship!
S
, 08/22/2023

I really appreciate these guys! After moving from out of state and having a solid mechanic you have trusted for over 14 years, it's like having to find a new doctor too! I am so thankful I found these guys! They have been so helpful and honest every single time! When I first moved here, I worked for UPS using my vehicle out of Oliver Springs. Let's just say that was not good. I've had issues ever since. Going up and down mountains was hard on my vehicle, and unfortunately, my light came on. I knew it was the transmission. I took it in, and they went thru it and told me they would check out everything they could and get back to me. Sadly, it was my transmission. They were super kind, and we decided it would be better to just get another vehicle, and they agreed. I really appreciate their honesty and hard work! Like I told them when I left...I will be back with the new vehicle because I know I found my mechanics for life here in Tennessee!
A
, 07/24/2023

Professional quality service. No hidden costs or surprises when it came time to settle up. Will definitely take my vehicles to them again for my repair needs.
G
, 07/11/2023

Pricing was extremely reasonable and everyone was so nice and knowledgeable! I had the A/C compressor in my 2014 Fiat 500L and it's working great!
T
, 06/20/2023

Very friendly and great work. I will return when I need more automotive work.
L
, 04/30/2023

Thank you B&M Automotive! They are Honest, Experienced, and affordable! The first place that I took it to said that I needed another motor and boy were they wrong. I'm glad that I found B&M and they were quick to let me know that I did not need another motor. They knew exactly what it was and had it fixed in no time. I highly recommend them!
A
, 04/05/2023

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