I had been meaning to post this to the forum and Area-51=99s email jog
ged my memory. I recently replaced the original mono master cylinder with a
unit that has a built in reservoir. See photo. I never liked the idea of c
ontinuously bringing DOT3 brake fluid into the cabin to top off the master c
ylinder due to brake pad wear. The new unit has more than enough brake flu
id capacity in the reservoir such that it shouldn=99t require refillin
g even with completely worn down brake pads.
Since the new unit mounts forward of the original, I fabricated a rail in or
der to utilize the original mounting holes in the tunnel. This left room fo
r the installation of a hydraulic line-lock parking brake. The plunger of th
e line-lock uses the existing filler hole on the top of the tunnel. The sid
e of the classic cockpit module tunnel is approximate 15 degrees off vertica
l. To allow the plunger to be perpendicular to the top of the tunnel I cant
ed the line-lock by the same amount on the mounting rail. See photos.
The new master has a smaller piston which really improves brake performance.
It=99s really quite remarkable. I am finally able to hold the plan
e without undue effort during the run up when cycling the CS prop at 4300 rp
m. In fact, the parking brake holds up to 5000 rpm. So happy to be rid of
the wedge I use to stuff into the slot as a makeshift parking brake. The op
eration of the line-lock is so simple; pull back on the brake lever and simu
ltaneously depress the plunger, then release brake lever. To undo the park
ing brake simply pull back on the brake lever. That=99s it. And the b
eauty of the design is such that you can=99t inadvertently set the par
king brake.
I did have to replace the spring, which serves to push the plunger back up, w
ith a softer one as the original one wouldn=99t allow the plunger to r
emain depressed when I released the brake lever. Additionally, I replaced t
he original bulky rubber knob on the plunger with a low profile one (just a s
crew actually). Came out nice IMHO.
I purchased the unit from AliExpress for less than $10 US. The Jamar parkin
g brake was a bit more expensive at $60, although knockoff are out there for
much less.
Erich Trombley
N28ET
Classic Mono 914
E-Props CS
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