What happens if I put R134a in a R1234yf car?

Author: Dr. Kasey Turcotte  |  Last update: Friday, March 28, 2025

The expansion valve setting for R-1234yf refrigerant is different compared to R-134a. Changing from R-1234yf to R-134a refrigerant may result in a system with incorrect refrigerant flow and heat exchanger mal-distribution which may cause a loss of cooling performance or durability concerns.

What if I put R134a in a R1234yf system?

Still, the answer is an emphatic, “No.” Not only would a retrofit of this type negate the environmental benefits of R-1234yf, but it would also be a violation of Federal Law under Section 203 of the Clean Air Act: “tampering” with a vehicle's emissions control device.

Are R134a and R1234yf fittings the same?

R-134a and R-1234yf systems have unique fittings so they can only be used with the appropriate corresponding refrigerants and equipment. R-1234yf is very expensive. This has led to end-users trying to replace the refrigerant in vehicles originally containing R-1234yf with R-134a, in an attempt to save money.

Is R1234yf a drop-in replacement for R134a?

The cooling capacity of R1234yf used as a drop-in replacement in a R134a refrigerant facility is about 9% lower than that presented by R134a in the test range. This difference in the values of cooling capacity obtained with both refrigerants decreases when the condensing temperature increases and when an IHX is used.

Can you flush a R1234yf system?

The ACX universal flushing unit is designed for refrigerants R134a and R1234yf. A proper flush of the air conditioning system is one of the most important tasks to be carried out during repairs and after the replacement of a compressor.

CAN YOU USE R134a in R1234YF AC SYSTEM

Is 1234yf oil compatible with 134a?

HFO-1234yf (R-1234yf ) has a global warming impact value of 1 versus 1300 for R-134a. It breaks down chemically in the atmosphere in only 11 days versus 13 years for R-134a! While R-1234yf oils are backwards compatible with R-134a systems, R-134a PAG oils are not compatible with R-1234yf systems.

How to tell the difference between R134a and R1234yf?

Most vehicles have a label or sticker under the hood that indicate whether the refrigerant used is R-134a or R-1234yf.

Why is 1234yf freon so expensive?

Switching to R1234yf refrigerant is a step towards a greener future, but it comes with higher costs due to advanced equipment, stringent regulations, and specialized training.

What are the disadvantages of R1234yf refrigerant?

Cons of R1234YF and the New Equipment
  • Higher Cost: One of the major drawbacks of R1234YF is its higher price. ...
  • Complex Maintenance: Alongside the increased cost, R1234YF also requires more complex maintenance compared to its predecessor. ...
  • Mild Flammability: Another concern with R1234YF is its mild flammability.

What happens if you put the wrong freon in your car?

You cannot mix refrigerant types, and putting the wrong refrigerant in your car will cause damage to the air conditioning system! If you're not sure which kind of refrigerant your vehicle takes, DIY A/C charging may not be for you.

Does R134a cool better than R1234yf?

However when the condensing temperature gets lower, R1234yf outperformed R134a. Over the range of operational conditions tested, the maximum difference in terms of cooling capacity is less than 5% and the COP is less than 10%.

Will a 134a leak detector work on 1234yf?

Technically yes, as the pressures are similar. In fact an empty R1234yf system could even be recharged with R134a and still work - this is why they changed the connectors again, and in part why the R1234yf recovery machines are designed to sense if the refrigerant is contaminated with R134a and abort.

How to recover contaminated refrigerant?

The best way to recover contaminated or unfamiliar refrigerants is to dedicate a recover-only unit to impure refrigerants. Some equipment manufacturers also offer recover-only units designed to remove these refrigerants. Some refrigerants might be contaminated with flammable substances such as propane and butane.

Can you use pag 46 in a 1234yf system?

In with the new

The new refrigerant type uses ND-oil 12, also a PAG 46 oil but with additives specifically for the R1234yf type refrigerant.

Is it illegal to put 134a in a 1234yf system?

Vehicles with R-1234yf have different service fittings than R-134a vehicles to prevent cross-contamination with different refrigerants. Also, it's illegal to put R-134a or any other refrigerant into a car originally equipped with R-1234yf.

Can I put R134a in a R1234yf system?

Refrigerant types are not to be mixed. The usage of dyes and sealants is discouraged.

When did cars stop using R134a?

In the United States, vehicles produced after 2021 no longer contain R-134A in the air conditioning system. In other parts of the world, including the United States, there are restrictions around using 1,1,1,2-tetrafluoroethane. Specifically, in California, retailers can deny selling customers canned R-134a.

Is R-1234yf a direct replacement for R134a?

There are three refrigerants that can be used to replace R-134a: R-1234yf, R-152a, and R-744.

Do all new cars use 1234yf refrigerant?

R-1234yf is used in almost every new car sold in the U.S., but the EU is discussing a ban and the industry is investigating alternatives like CO2 and propane.

Does it matter what freon I put in my car?

Please remember that using the wrong type of refrigerant for your system can create a hazard or cause serious damage so it is very important to get it right. Don't worry though, as AC Avalanche recharge hoses can only work on systems of their respective type, eliminating the risk of using the wrong type.

Will AutoZone recharge my AC?

An AC leak will lead to warmer air from your vents over time. In most cases this can be fixed with a proven stop leak additive to seal up any leaks. When it's time for an AC recharge, turn to AutoZone.

Do you need a license to buy R-1234yf?

If you are purchasing less than 2 pounds of either R-134a or R-1234yf, you are not required to have a license to purchase either refrigerant. However, if you are working with 10- and 25-pound single-use recyclable cylinders you will need Section 608 Technician Certification.

How many cans of R134a do I need?

Most cars hold between 28 and 32 ounces of refrigerant (or about 2—3 12oz cans), however larger vehicles and those with rear A/C will likely hold more. Check your vehicle manual for the system capacity for your specific vehicle.

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