> Sven,
>
> I had mega problems filling and bleeding the system. First, disassemble
> the master cylinder and check the the two nylon washers are not binding
> in the bore. Mine were, so I sanded the edges, until they moved,
> freely. I tried various methods for pushing or pulling the fluid
> through the system, to no avail. I'm using ATF. What finally worked
> was to fill the reservoir and then use 30# air pressure to push it
> through. I stopped the pressure when the reservoir was almost empty, to
> refill. It took about three fills to top off the system. Once the
> system was dropping ATF out of each caliper, I closed them off and then
> had my son open one, as I applied more pressure to the reservoir. When
> the bubbles stopped, I did the other side. It was a pain, but it worked
> and A055 now has a set of working breaks...
Sorry to say this, but you won't have working brakes for more than a year or
two - or possibly less.
The standard seals in the Jamar twin master cylinder are designed for the
use of automotive brake fluid Dot 3, 4 or 5.1. If you use ATF (or the
mil-spec aviation brake fluid) the seals will deteriorate.
The bad news is that the standard seals in the callipers are designed for
ATF (or mil-spec aviation fluid) and if you use DOT 3, 4 or 5.1 THEY will
deteriorate.
This is why the factory specifies DOT 5 - silicone brake fluid which will
not affect either types of seal.
I have decided to go Automotive - thanks to the help of Ivor Phillips of
this List. I had already messed up (testing) my master cylinder seals with
ATF so he provided me with new seals for the master cylinder, the callipers
and the Matco parking brake valve all to work with Automotive brake fluid -
I will be using DOT 5.1
I admit that at the moment I am using two of the floor based master
cylinders, with the changed seals for tri-gear use, as finger style brakes.
I am used to them, but no way can they be described as easy ! And in fact my
co-builder filled the systems up with Automotive fluid so I expect part of
the sluggishness is due to swelled seals. I will be putting in the Jamar
dual master cylinder at the time of the annual in March. I am researching
and getting everything together, ready !
I will increase the power of the internal spring a little by putting in a
flattened spring washer (maybe 1.5 mm thick) into each bore before the
spring ( which is followed by the piston ... Etc. I will be sure that the
spring washer is nice and clean !
Richard
Richard F.W. Holder 01279 842804 (POTS)
Bell House, Bell Lane, 01279 842942 (fax)
Widford, Ware, Herts, 07860 367423 (mobile)
SG12 8SH email : rholder@avnet.co.uk
Europa Classic Tri-gear : G-OWWW, High Cross
PA-28-181 : Piper Archer : G-JANA, EGSG (Stapleford)
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