DuaneFamly@aol.com wrote:
> I have decided to change from the Jamar master cylinder to a pair made by
> Matco. I was wondering which model have other builders chosen to use and
> what kind of orientation did they use to install them into the center
> console.
I just did a Jamar to Matco conversion today.
The conversion turned out to be quite easy.
I bought two Matco MC-4D's and a few fittings, used some aluminium
profiles, and some AN3 hardware. Total cost about 200 US$.
To save some work, I decided to cut off the front-end of the Jamar
brakes to use it as a bracket. The levers and position of the assembly
can be left as is. Very convenient also is that consequently the
existing slots for the levers don't have to be moved. The Jamar forks
fitt on the Matco cylinders as well.
Because there is now only one bolt to attach the forward bracket to the
shelf, I drilled two more holes to secure the bracket with two
additional AN3-10A bolts. You can make some anchor nuts for these on the
shelf, but because I have an access cover on the bottom of the airplane
I just used two regular stiff nuts with a washer. It is not something I
plan ro remove often, so why make it fancy when two nuts will do?
For the rear part of the Matco cylinders I made a new bracket. The
Matco's fit very precisely in the available space, so you can't just use
a rectangular bracket but have to shape it a bit. I have not measured
the dimensions of my bracket, but trust that anyone going the same route
will find out easily how to construct it. An AN3 bolt will go right
through the holes in the cylinders. Some washers and spacers will make
it nice and tidy. I used 4 AN3-5A bolts to secure this bracket to the
shelf, again using stiff nuts from the underside.
Another fortunate discovery was that with this setup the two existing
hoses from the parking brake to the cylinders are exactly the correct
length. The only change had to be made for the hose of the reservoir;
the Matco's of course each need to have a connection to it. Since the
existing hose was now too short, I connected it to a T and used some
left over hose to connect it to both master cylinders.
Filling and bleeding the new system with aircraft hydraulic fluid
(instead of the silicone stuff) turned out to be easy as well. I used a
syringe to fill it up from the bottom, flush out the remainder of the
silicone stuff, and that was enough to get the air out of it as well.
What a difference with the Jamar brakes!
Compared to the Jamar thing the Matco's feel much better. No jerky
movement, less play, a stronger spring, much more braking force with
less effort, less weight, etc. I'm very happy with the conversion!
If anyone needs some Jamar stuff, let me now. I still have the cylinder
housing and everything that belongs inside, the bracket is gone. Will be
happy to send it to someone instead of throwing it into the dustbin.
> I have never been one to reinvent the wheel.....or brake in this case.
Hope this is of some help. If you need more detailed pictures, let me know.
Frans
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