Re: Of DOT3, alcohol antifreeze, vinegar and other alchemy

Posted by Tim Cole On 2010/5/20 17:27:15

Hi Folks

Dot 5 silicone brake fluid is standard equipment for AMG HMMV, AMG Military trucks, etal.; as well as H-D motorcycles. When I was overseas we never had any hydraulic problems with those brake systems even under severe sub-saharan service. Vehicles using DOT 3 had lots of hydraulic problems. I also saw mixing of DOT 5 because the military stocked DOT 5 as a matter of NSN. It was pretty much inert.

I have a vial of ancient brake fluid I drained from a barn car and it is not the same as modern DOT 3.

Glycols are Hydroxl-alcohols and the MSDS for DOT 3 shows twelve glycol elements.

I have run into the brake switch failure problem myself and it really leaves me scratching my head for a cause. Although, I do think those hydraulic brake switches are a lousy system and they fail using DOT 3 on a regular basis as well.

Also, brake lines do not seem to rust from the inside out and I have cut very rusty brake lines in two to verify this point. I have a few lying around that I use for demonstration purposes.