Hello, I just bought an M109A3 and I'm new at this. The truck has a soft pedal. It's in great shape and I believe has low mileage and hours. My buddy and I where going to bleed the brakes, but where not sure what to use in the master cyl. There is a tag inside the door with the name of the unit which did the maintenance on the truck with a phone #. So we called and spoke to a very nice mechanic. The fluid in the 109 I have is lemon yellow and I told him this. He told me that it's hydraulic oil 10 wt. I went to the hydraulic shop and they told me AW32 = 10wt. I called the mechanic again and he said that was correct. I asked why hydraulic oil instead of DOT 5. He told me that when units operate outside of the US, DOT 5 is not always available or accessible to a isolated unit and that 10 wt usually is. So now they use this. I played with some DOt 5 and the oil. They seem to mix and act compatable. I took a sample of the stuff in the master cyl and mixed it too. Didnt see any problem with this either. Anybody know about this? Thanks