I recently had a problem in an airplane with the brakes releasing slowly -- this squared off a couple of tires (on touchdown) before it came to me. New pads and new disks had recently been installed, so I assumed the problem was in the master cylinder(s). When I took the feed hose off the first master cylinder I expected a flow of 5606 (the reservoir is above the cylinder) -- nothing! When I removed the pressure line I got a slow drip of something akin to raspberry jam. Pressing the piston deposited a glob of red jelly on the rag. The stuff was so think that it would hold a round shape 1/2" high.
It was the color of 5606 (the specified fluid), but much, much thicker, yet still slick. Mixing it with 5606 cut it a little but not completely. The temperature was 60F so it was not due to cold. Mineral spirits has the same effect on this stuff as it does on 5606 (minimal solvent action). Avgas does clean it, but more slowly than it does 5606, probably just because of the viscosity. I didn't try any other solvents. The fluid smelled the same as 5606 although there was 5606 mixed in with it so it could be neutral. Color was consistent so the bad stuff is likely red also.
Do you have any idea what this is? Is it any variant on 5606 (old, known contaminant, etc)? Is there anything that you know of that can contaminate 5606 and cause this?
Is there a place that would be interested in analyzing a sample of it in case it is some breakdown product of 5606?
Thanks for any insight you can give.
It was the color of 5606 (the specified fluid), but much, much thicker, yet still slick. Mixing it with 5606 cut it a little but not completely. The temperature was 60F so it was not due to cold. Mineral spirits has the same effect on this stuff as it does on 5606 (minimal solvent action). Avgas does clean it, but more slowly than it does 5606, probably just because of the viscosity. I didn't try any other solvents. The fluid smelled the same as 5606 although there was 5606 mixed in with it so it could be neutral. Color was consistent so the bad stuff is likely red also.
Do you have any idea what this is? Is it any variant on 5606 (old, known contaminant, etc)? Is there anything that you know of that can contaminate 5606 and cause this?
Is there a place that would be interested in analyzing a sample of it in case it is some breakdown product of 5606?
Thanks for any insight you can give.
