John, There are a couple of things that can be going on here.
#1, make absolutely sure you are using 5606 hydraulic fluid. In a pinch, sometimes Automatic Transmission Fluid gets used instead of 5606 hydraulic. I have seen it cause the brakes to slowly lock up as described in your previous email. Both brakes at the same time from independent master cylinders! At first I thought it was a master cylinder porting problem, but it turned out that the owner had used ATF instead of 5606. When the fluid was changed out for 5606, the problem went away and never returned. #2, make sure your master cylinders are not overserviced, and that they vent externally properly. Otherwise, as the fluid warms up, it expands in the direction that moves easiest. If that happens to be the slave cylinders, your brakes will drag or lock. Jeff Scott On Mon, 30 Jan 2006 08:58:47 +1100 "Martindale Family" <johnja...@optusnet.com.au> writes: > Hi Larry > > The problem occurs on both sides which are independent of each other > so I reckon its something to do with the design or my setup. The > Great Plains model has a resevoir integral with the master cylinder. > I have the master cylinders mounted vertically in a toe/heel > arrangment with the plunger downwards and bleeder at the top and > maybe this affects the way the internal ports (?) compensate. > It would really help if I knew how they work. I need a picture. > > As you say, it is possible the plunger is binding and not free to > travel back to its start position but equally there is no particular > force like a spring or anything to do this. It must rely on residual > pressure to return it. Maybe I'll pull one down and navel gaze it. > It doesn't happen as a result of me applying and releasing brakes > but rather after a period of sitting still......they sort up pump > themselves up on their own!!......typical of my aircraft...a mind of > its own. > > John > > Martindale Family > 29 Jane Circuit > TOORMINA NSW 2452 > AUSTRALIA > > ph: 61 2 66584767 > email: johnja...@optusnet.com.au > web: http://www.members.optusnet.com.au/johnjanet/Martindale.htm
