Maatco parking brake

[Archer39J]

My Matco install is below, parking break engaged as shown. It uses a camshaft, springs, and valves.

If I were to do it again I would raise the brake valve so there was no chance of contact with the right co-pilot's foot. As it is I think it will be fine, the open position has the arm down and I can see it easily while seated. Having a parking break in-line with my mains as opposed to a separate master cylinder, I want to be able to visually check it is disengaged.

I finally got around to disassembling my valve to figure out why it was seeping through the arm. The inside edges of the valve are very sharp and its easy to slice a piece of the o-ring off when installing the camshaft. Mine came from the factory this way so I wonder if this is a common issue, if folks don't notice, or what. I was able to get the same o-rings from my local ACE aircraft section, they are a common size that I don't remember off the top of my head but they are easy to find.

Works great now and no seepage at all, I'm using generic ATF for those who care.

Dave

matco2.jpg
matco1.jpg
macto3.png

[Nev]

An advantage of installing on the firewall is that the valve can be viewed when inflight. If there's an issue, it can also be accessed. In practice I wasn't sure if I would be diligent enough to check it even so.

[JimParker256]

I've had several issues caused by the lack of a parking brake, usually involving a sloped tie-down spot and no one around to chock the tires for me before dismounting. In one case, before I could manage to chock the nose gear, my airplane rolled far enough to partially block the taxiway. I lost about a year off my life our of fear that I wouldn't be able to stop it from hitting the twin parked downhill from me).

A parking brake would have been extremely helpful in those situations. I would have been able to simply set the parking brake, exit the plane, and chock / tie-down the plane at my leisure, then go back into the cockpit to release the parking brake... No muss, no fuss, no panic-induced sweat...

As someone else mentioned, I don't consider a parking brake to be a viable substitute for chocking and/or tying down your airplane before you walk away. For anything more than just a couple of minutes, that's a risk I'm not willing to take... But it sure would have eased the pressure I felt in those "parking uphill from an expensive plane" situations...

[Utah-Jay]

I took a poll of backcountry pilots around my area, it was about 3-1 for no parking brake. I did not install one. I have yet to be anywhere I actually needed one when I had one available in the S-21.

[BravoGolf]

A military twin that I flew had hydraulic pressure gauges on the brake system. Part of the prelanding check was to pump the brakes and visually confirm the pressure returned to zero. A small transducer and gauge could be easily installed on the Bearhawk brake system. Tap the brakes on downwind, confirm the pressure returns to zero . But that kind of redundancy adds weight.