Attempting to clean an e39 M5 ABS valve body

 

I’m using denatured alcohol to try to free up a stuck valve in my ABS hydraulic unit from an e39 M5. The port labeled HL (rear left) was fully clogged before I started this process. As you can see, it is now moving air (although not as much as the VL port (front left). It took about 15 minutes of persistent effort before it started to free up. I didn't want to lug my compressor inside, so I'm just using my power bleeder with an air-hose at 20psi. I would not recommend using anything other than denatured alcohol. Stay away from penetrating oils. I’m not even sure this is a good idea, as your brakes are really important. In fact, I didn't end up using this valve body - I purchased a second hand unit from ebay. This will serve as my emergency backup.