Peter,
My brake master cylinder has had the same problem as what you are describing. I
replaced the separate seals with ones from the local car shop. This appeared
to solve the problem, but the piston was still sticking now and again. A couple
of days ago I took it all apart again to check the seals: they were still
exactly
the orignal size (I kept a new one separately for comparison). My conclusion
is that the spring is too weak and/or the Dot5 is not a good lubricant.
I solved the problem for the time being by adding a smaller diameter spring
inside
the existing ones; they are also a bit shorter. The handles now snap back
very nicely in dry mode, just as I expected them to on day 1. I still have to
fill/bleed the system to check it out properly. I would prefer to use one strong
replacement spring.
Karl
From: Richard Holder rholder@avnet.co.uk
Subject: Re: Europa-List: Finger brakes
Date: Wed, 18 Aug 2004 17:06:56 +0100
-- Europa-List message posted by: Richard Holder rholder@avnet.co.uk
-- Europa-List message posted by: "Peter Field" peter.field@hgfield.co.uk
Has anybody experienced the springs in the cylinder of the finger brakes not
being powerful enough to return the plunger assembly to its usual resting
position after operation?
If so, what is the cure?
Peter Field
Kit 566
I bought one from Europa Florida. I took it apart - there was lots of swarf
inside. It had also been mismachined, the end inch of the bores where the
seals normally go when at "rest" were badly machined with the smooth part of
the bore not reaching the open end.
After some discussion (somewhat one way) with Jamar in the US, I got John
Hurst to admit that there had been a faulty batch from Jamar and he sent me
a replacement, which does not have the faulty machining.
So undo the end plates (mind the piston and seals as they should come out)
and look at the quality of the machining.
When trying it, be sure that there is plenty of lubrication of the fluid
that you are using (I have a litre of DOT 5 for sale !).
Also remember that in use there will be considerable back-pressure from the
callipers which will also help to push the master cylinder pistons back.
Jamar have assured me that the seals in the twin master cylinder are
suitable for use with ATF/Aviation Brake Fluid and as this is also the
correct type for the callipers on the tri-gear it should be possible to use
ATF/Av Brake Fluid rather than DOT 5 (which is why mine is for sale !)
Having said all that I haven't yet installed mine - waiting for down time
during the winter. Too nice to take it off-line at the moment ! I am getting
used to my twin finger brakes built from the standard (originally floor
mounted) master cylinders, with long extension levers.
Richard
Richard F.W. Holder01279 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)
|