OZ wrote: > By the way, Mark, by using the wrong parts on the brakes on my Piet, I > found that some O-ring materials aren't happy with brake fluid. I realize > that aviation (red) brake fluid isn't the same as DOT automotive fluid, > but here's a reference that might help in general...
Yep, I did that homework last night. Funny thing is that I got some of my info from efunda as well. Although I could switch to some other "brake fluid" since I'm replacing every single "rubber" part of the brake system, typical DOT brake fluid does require some specific seal material. Since Buna-N (nitrile) is such a ubiquitous seal material for hydraulic systems, and is rated as having "excellent" compatibility with MIL-PRF-5606 (the red stuff most of us use), I can't go wrong with that. I'm not counting my chickens yet though, until I get the brake caliper seals and identify the material to be sure. The o-rings I have are Buna-N, and I could easily buy Viton, which is also rated excellent with 5606. By the way, these master cylinder o-rings are #012. See http://www.efunda.com/designstandards/oring/oring_chemical.cfm?SM=none&SC=MIL-H-5606 for the material compatibility of 5606. Something else I learned was that 5606 is being replaced with MIL-PRF-83282 for military use, because of flammability issues. I thought I'd just use that, but after finding that it was going to cost me $30 for a quart, and already owning two quarts of 5606, it doesn't make a lot of sense to swap. Another factor was reading the article on Grove's website, http://www.groveaircraft.com/fluid.html . Mark Langford ML at N56ML.com website at http://www.N56ML.com --------------------------------------------------------
