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AC system decontamination is how Route 66 Auto Repair in Upland deals with a system that holds the wrong refrigerant, a mixture, or sealer from a kit. We test what is inside before our equipment connects, because contamination spreads to every car serviced after it. If yours is contaminated, we explain the extra steps and costs in writing before anything is removed.
How does a system get contaminated?
Most contamination comes from well-meant top-offs. A can bought online may not hold the refrigerant your vehicle specifies. A kit with sealer adds a chemical that can harden inside the system. Previous repairs may have left air and moisture in the lines.
Contamination changes pressures, cuts cooling, and can damage the compressor. It also damages shop equipment, which is why we test first.
Signs of contamination
- Pressure readings that do not match any normal pattern
- A recharge kit used in the past, with sealer listed on the label
- A service port that does not match your vehicle's original fittings
- Cooling that got worse after a top-off
- Purity test failing before we connect our machine
Our decontamination process
Step 1: Test purity
A refrigerant identifier samples the system before any recovery.
Step 2: Recover separately
Contaminated refrigerant goes into a dedicated tank for proper handling, never into our clean machine.
Step 3: Clean the system
Lines, condenser and evaporator are flushed where approved, and parts that trap sealer or debris are replaced.
Step 4: Rebuild the protection
New drier, metering device and seals go in, with oil set to spec.
Step 5: Vacuum and charge
A vacuum hold and a charge by weight are followed by a performance test.
What's included in AC decontamination
Included on the work order
- 01Refrigerant purity test
- 02Separate recovery of contaminated refrigerant
- 03System flush as approved
- 04New drier, metering device and seals
- 05Oil set to specification
- 06Vacuum hold, charge by weight and performance test
Can a contaminated system wait?
Need now: call
- Compressor noise or high pressures from contamination
- Any sealed-side repair, since contamination must be cleared first
Need later: book
- A system that cools acceptably and will not be opened soon, with you aware of the risk
How pricing and timing work
Contaminated refrigerant costs more to handle than clean refrigerant, and that is its own line. Flushing and parts depend on how far sealer or debris traveled. Details on the flush are on AC system flush. If sealer clogged the valve, see AC expansion valve cleaning. Oil handling is explained on AC compressor oil change. For AC service standards, the EPA vehicle AC page (opens in a new tab) is a good reference.
After decontamination
Skip store-bought top-off kits from here on. If cooling drops, a leak test finds the cause without adding anything unknown to the system.


Frequently asked questions
Why do you test before servicing my AC?
Contaminated refrigerant damages service equipment and can spread to other vehicles. Testing first protects your car and every car after it.
Can you just add more refrigerant on top?
Adding to a contaminated system makes pressures unpredictable and can harm the compressor. The contamination has to come out first.
Will you refuse my car if it is contaminated?
We tell you what we found and what cleaning involves. You decide whether to go ahead, and nothing is recovered or charged without your approval.
