What kind of power steering fluid should you use in a 1987 BMW 535 IS?

You should never use conventional power steering fluid in a 1987 BMW 535i. These cars use a hydraulic system with a separate reservoir for the power steering fluid, which is different from the conventional system where the fluid is shared with the transmission.

Here's what you need to know:

* Specific fluid: BMW recommends using BMW power steering fluid (Part number 83 22 0 140 787) in these models.

* Avoid conventional fluid: Using conventional power steering fluid will damage the system. It can cause seals to deteriorate, leading to leaks, and the fluid can mix with the transmission fluid, causing serious problems.

* Check the manual: Always refer to your owner's manual for the specific fluid recommendations and instructions.

Important Note: This information is based on general knowledge. Always consult your owner's manual and a qualified BMW mechanic for specific instructions and guidance for your vehicle.