No. Do not use automatic transmission fluid (ATF) in the power steering system of a Mercedes-Benz. Use the Mercedes-approved power steering fluid specified for your model.
Mercedes power steering systems rely on a dedicated hydraulic fluid formulated to work with the pump, rack, and seals in a given vehicle. ATF is designed for transmissions and has different viscosity and additive packages that can cause seal swelling, leaks, or degraded steering performance. Always verify the exact MB specification for your model in the owner's manual or with a Mercedes dealer, as requirements can vary by year and model.
Fluid specifications by model era
Modern Mercedes-Benz models (2010s–present)
Most contemporary vehicles require a Mercedes-Benz power steering fluid that meets MB 236.x specifications. Use only PSF that explicitly states MB 236.x compatibility; ATF is not recommended unless Mercedes explicitly approves it for a specific model and year.
Older Mercedes-Benz models
Earlier hydraulic systems may have different MB PSF requirements, sometimes tracing to older MB 236.x catalogs or other MB designations. If you own a pre-2010 model, check the factory maintenance sheets or consult a Mercedes specialist to confirm the correct specification. Do not assume ATF is acceptable.
What should you use and what should you avoid?
To ensure compatibility, follow these checks before topping up or servicing the PS system.
- Check the owner’s manual or service bulletin for the exact Mercedes-Benz specification (commonly MB 236.x) of the power steering fluid for your vehicle.
- Inspect reservoir labeling or the cap for MB PSF instructions and compatible brand names.
- Use only a power steering fluid that explicitly meets the MB 236.x specification; avoid any fluid labeled as ATF unless MB specifies it for your model.
- Avoid mixing different fluids; if you need to top up, ensure the new fluid matches the existing MB spec.
Using the correct MB PSF preserves pump performance, steering feel, and the longevity of seals and hoses.
What to do if ATF has already been added
If ATF has been put into the power steering reservoir, take action promptly to minimize potential damage. Driving with ATF in the PS system can lead to seal swelling and leaks and may impair steering.
Recommended steps:
- Limit driving and schedule service as soon as possible to minimize risk.
- Have the power steering reservoir drained, the system flushed, and refilled with the correct MB PSF by a qualified technician.
- Bleed the system if required to remove air pockets.
- Inspect for leaks at pumps, hoses, and the steering rack after service.
- Document the specification used for future reference and maintenance.
After the flush and refill with the correct PSF, the steering should return to normal function. If issues persist, seek professional assessment.
Summary
The bottom line is straightforward: Mercedes power steering systems require the manufacturer-specified power steering fluid (MB 236.x family) and should not use ATF. If ATF has been added, have the system flushed and refilled with the correct PSF by a Mercedes-trained technician, and follow up with proper bleeding and leak checks. Always consult the owner's manual or a dealer for the exact specification for your vehicle’s year and model.
Will ATF work as power steering fluid?
Conversely, some vehicles can use ATF as their power steering fluid, but make sure it's approved by the manufacturer prior to doing so or it could cause wear to components like the rack and pinion internally.
What power steering fluid for Mercedes?
Pentosin 1405116 CHF 11S Long-Life Synthetic Hydraulic Fluid for Audi, Bentley, BMW, Chrysler, Dodge, Jeep, Mercedes-Benz, Mini, Porsche, Saab, Volkswagen, Volvo, and More; 1 Liter.
What happens if you put power steering fluid in instead of ATF?
Power steering fluid and ATF are the same thing. The OEM fluid may contain additives that make it more tailored to the use case, but it's all just hydraulic fluid. I would replace it anyway just to be sure all the fluid properties are exactly as designed, but using the universal stuff is not likely to damage anything.
What type of ATF does Mercedes use?
And earlier 5gronic transmissions pendison ATF-134 is also backwards compatible with earlier Mercedes 4 and 5-speed transmissions requiring specification 236.12.