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Best Auto Repair, Knoxville

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

 85 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

Stopped in to get help with an 01 Dodge we are rehabbing, the guys are very nice and very helpful! Took care of my abs brake sensors that were melted in!
H
, 08/18/2022

Just wanted to give a shout out to Bob at B & M. Very professional and did great work on my suspension repair.
D
, 08/17/2022

I had an amazing experience here at B & M! Both my mom and I had been having problems with our Toyota Priuses, this is the closest shop that works with hybrids but unfortunately we live about an hour and 15 minutes away. Boy am I glad that we drove this whole way! We arrived there as they opened and told them about the cars problems and stayed to chat for a while. Marty, the main mechanic mentioned how they had been operating with just two employees and the manager because everyone else had quit. Because of that they were unsure how soon they could get to my car. I wasn't super happy about that but I understood that it was out of their control. Because I was trying to leave shortly for the start of school, I really didn't have much time to waste, but again, they couldn't do much about it. My mom and I had about a days worth of errands to run around Knoxville so we told Marty that we would be around for that day in case they miraculously finished with the car. About an hour or two before they closed we got a call about the car. Unfortunately, my car was totaled, but because they were so fast with their diagnosis I still have plenty of time to figure out what to do as far as school goes. I would highly recommend coming here for your auto repairs. They were very considerate to my need for quickness even through their rough times, they were all very personable and I really enjoyed standing there listening to them talk, and so if ever I come back after college, they have gained themselves a customer for life. Thank you so very much Marty, Bob, and Gary.
B
, 08/05/2022

I had them do some repairs on a somewhat Frankenstein VW trike I just acquired. They did a FANTASTIC job figuring out what I had and then getting it road ready. A special thanks to Diego. Dude, you are my go-to guy for anything I need on this trike. Awesome people and awesome service.
T
, 07/27/2022

These guys are great. Repair was quick and price was well below the estimate.
j
, 06/14/2022

Great
D
, 05/22/2022

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