Ask An Expert: Steering Wheel Fluid

All this year, we've been asking you to send us the classic questions you've been struggling with.

With a strict, national lockdown earlier this year, we understood that visiting your local classic specialist, going to events and meeting up with fellow club members was almost impossible and made getting your classic conundrums resolved very difficult. This year we've asked local specialists and clubs to answer your questions on everything from insurance to storage, and from oil changes to stale fuel. We'd really love to continue this service throughout 2021, so if you have a burning classic question, let us know! Simply fill in our Ask An Expert form, and your question may be chosen to be answered in our next newsletter.

So, without further ado, here's our final Ask An Expert question for 2020! David Knapp asked:

How important is it to stick with the same brand power steering fluid when topping up reservoir? My 1993 540 BMW has a slight leak (vapour) and it’s been around for ages, I bought a sealant product but it tells me to avoid using it with my current Pentosin.

We spoke to Nick Thomas, Technical Director at the BMW Car Club GB for the answer.

"You can change fluids, but we'd advise against mixing brands as the properties of one may adversely impact the performance of the other. With a series of pipes, hoses and connections that make up your power steering system, we recommend that you flush every last drop of fluid before changing to your preferred manufacturer.

For peace of mind and with the system emptied, avoid using a sealant which may simply mask the issue, try and locate the source of the leak, these repairs are not usually difficult on the E34 540."

We would also add that if you would prefer not to fix this issue yourself at home, you can find a local BMW specialist garage near you using our Find A Garage tool.

The information contained in this blog post is based on sources that we believe are reliable and should be understood as general information only. It is not intended to be taken as advice with respect to any specific or individual situation and cannot be relied upon as such.