2025 Peterbilt 579: A/C Refrigerant & Oil
AI-generated reference. Always verify torque values, fluid capacities, intervals, and procedures against the manufacturer's service manual or OEM repair information before performing work. Repairius is not liable for damage from acting on this content without verification.
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Quick answer
- Refrigerant type: R-1234yf
- Full system charge: 45 oz (1275 g)
- PAG oil type: PAG 46
- PAG oil amount: 10.8 oz (320 mL)
- Low-side service port location: Near the A/C compressor, on the low-side line.
- High-side service port location: On the high-side line, near the condenser.
Why R-1234yf matters
The 2025 Peterbilt 579 uses R-1234yf refrigerant, which has a much lower global warming potential than the R-134a used in older vehicles. This is good for the environment, but it also means that you'll need a special machine to recover and recharge the system. R-1234yf is also more expensive than R-134a, so it's important to have the work done by a qualified technician to avoid costly mistakes.
Recharge procedure
Recharging the A/C system in a 2025 Peterbilt 579 is not a DIY job. It requires a special machine to evacuate the system, and the charge must be precise. Overcharging or undercharging the system can cause damage to the compressor and other components. It is also important to use the correct type and amount of PAG oil. Using the wrong oil can cause the compressor to fail.
Common A/C problems for this vehicle
The most common A/C problems for the Peterbilt 579 are compressor failures, condenser issues, and evaporator leaks. Compressor failures are often caused by overcharging or undercharging the system, or by using the wrong type of PAG oil. Condenser issues can be caused by road debris, and evaporator leaks are often caused by corrosion.
When to call a pro
If you are experiencing any problems with your A/C system, it is best to have it checked out by a qualified technician. They will be able to diagnose the problem and make the necessary repairs. It is also a good idea to have your A/C system serviced on a regular basis to help prevent problems from developing.
Disclaimer: The information in this article is for informational purposes only. It is not intended to be a substitute for professional advice. Always consult a qualified technician for any A/C-related issues.
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More specs for the 2025 Peterbilt 579
Oil Capacity & Filter
Capacity, weight, filter PN, drain plug torque, change interval.
Fluid Type Specs
Engine oil, coolant, ATF, diff, brake, PS, DEF — with OEM spec numbers.
Coolant Capacity & Type
Total system capacity, OEM coolant spec, flush interval, bleed tips.
Transmission Fluid & Service
Trans model, fluid spec, capacity, filter PN, service interval.
Torque Specifications
Lug nuts, drain plug, caliper, axle nut, plug, key fasteners.
Brake Pad & Rotor Specs
Pad PNs, rotor size, min thickness, caliper torque.
Tire Size & Pressure
OEM size, cold psi, bolt pattern, wheel size, TPMS.
Battery Size & Group
Group size, CCA, AGM/flooded, dimensions, reset note.
Bulb Sizes (Headlight, Tail, Fog)
Headlight, fog, tail, turn, reverse, interior.
Factory Maintenance Schedule
Service intervals by mileage, severe-duty notes, known issues.
Towing Capacity & Payload
Max tow, payload, GVWR/GCWR, hitch class by trim.
Fuse Box Diagram & Amperage
Fuse box locations, layout, amps, and what each fuse controls.
Serpentine Belt Routing & Length
Belt routing, length, rib count, OEM + aftermarket PNs.
Wheel Alignment Specifications
Camber, caster, toe ranges (front & rear), adjustability notes.
Paint Color Codes
All factory colors with paint codes, sticker location, touch-up tips.
Wiper Blade Sizes
Driver/passenger/rear blade size, attachment, OEM + cross-refs.
Spark Plug Type & Gap
Plug PN, gap, torque, interval by engine.
Transmission & Axle Gear Ratios
Trans gear ratios, axle ratios, RPO codes, tow vs MPG impact.
Key Fob Programming
DIY programming steps, FCC ID, fob PN, battery, transponder.
Same spec — other model years
Maintenance & repair guides
2025 Peterbilt 579 Maintenance Schedule →
Available maintenance guidance; confirm the manufacturer schedule.
Repair planning references →
Plan the scope of work; detailed procedures need configuration-matched evidence.
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