hvac

AC Compressor Oil Add

for 2021 Ford F-150 3.5L V6 EcoBoost · 4WD

Difficulty

Moderate

Time

36 min

Tools

Steps

This procedure adds PAG oil to the AC compressor to maintain proper lubrication levels after refrigerant loss or component replacement.

Warnings

⚠️R-1234yf refrigerant is mildly flammable. Never use near open flames or hot surfaces.

⚠️Refrigerant can cause frostbite on contact with skin. Always wear safety glasses and gloves.

⚠Only use PAG 46 oil compatible with R-1234yf systems. Incorrect oil will damage the compressor.

⚠AC system must be properly evacuated and recharged by a certified technician according to EPA regulations.

ℹ️Engine must be off and cool before beginning this procedure.

Tools required

AC refrigerant recovery machineEssential

AC manifold gauge setEssential

PAG oil injector toolEssential

Torque wrenchEssential

Socket set (metric)Essential

AC vacuum pumpEssential

Safety glassesEssential

Nitrile glovesEssential

Clean shop towels

Digital scale (for measuring oil)

Parts

AC system O-rings × 2 — Use OEM specification
R-1234yf refrigerant × 1 — As needed to recharge

Fluids

PAG 46 oil (ND-12 compatible) — 0.15 qt

Preparation

Park vehicle on level ground and engage parking brake
Ensure engine is completely cool
Verify AC system is not currently running
Identify the low-side service port on the suction line near the accumulator
Have refrigerant recovery machine and evacuation equipment ready

Procedure

1
Recover refrigerant from AC system
Connect AC recovery machine to both high and low side service ports. Follow machine manufacturer instructions to completely recover all R-1234yf refrigerant from the system. Note the total amount recovered for recharge reference.
⚠️Only use approved R-1234yf recovery equipment. Do not vent refrigerant to atmosphere.
2
Disconnect suction line from compressor
Locate the suction line connection at the rear of the AC compressor on the passenger side of the engine bay. Use appropriate socket to loosen and remove the AC line fitting bolt. Carefully separate the line from the compressor and cap both openings immediately to prevent contamination.
⚠Residual refrigerant pressure may remain. Ensure system is fully recovered before disconnecting lines.
3
Remove old O-rings and inspect
Remove and discard the old O-rings from the AC line fitting. Inspect the mating surfaces on both the compressor and line fitting for damage, corrosion, or debris. Clean surfaces with a lint-free cloth if necessary.
4
Add PAG oil to compressor
Using the PAG oil injector tool, add the appropriate amount of PAG 46 oil through the suction port opening on the compressor. For oil addition only (no component replacement), add 1-2 oz (30-60ml). If replacing components, refer to component oil capacities: compressor replacement = 4 oz, condenser = 1 oz, evaporator = 2 oz. Rotate compressor clutch by hand several times to distribute oil internally.
⚠Do not overfill with oil as this will reduce AC cooling efficiency and may damage the system.
5
Install new O-rings with oil
Install new O-rings onto the AC line fitting. Apply a thin coating of fresh PAG 46 oil to both new O-rings before installation to ensure proper sealing and prevent damage during assembly.
6
Reconnect suction line to compressor
Remove caps from compressor port and line fitting. Align the suction line with the compressor port and hand-thread the fitting bolt. Tighten the AC line fitting to specification using a torque wrench.
Torque spec
AC Line Fittings20 Nm (15 lb-ft)
7
Evacuate AC system
Connect AC vacuum pump to service ports. Evacuate the system for a minimum of 30 minutes to achieve a deep vacuum (below 500 microns). Monitor vacuum gauge to ensure system holds vacuum for at least 10 minutes after pump shutoff, confirming no leaks are present.
⚠If system does not hold vacuum, there is a leak that must be repaired before recharging.
8
Recharge AC system with R-1234yf
Using proper AC service equipment, recharge the system with the correct amount of R-1234yf refrigerant. The 2021-2024 F-150 3.5L EcoBoost requires approximately 1.65-1.85 lbs (26-30 oz) of R-1234yf. Charge to the amount previously recovered or per underhood AC specification label.