While I had the panel out, I decided to rebuilt the brake master cylinders. The left one was feeling like it was bleeding off a bit when brakes were applied hard. The brake master cylinders in the Vans RV-4s are mounted upside down, at least the earlier ones are because of interference problems with the center tunnel.
I decided to do both sides while access was so easy.
The left brake master cylinder has black oily gunk on the rod and spring, confirming my suspicions that it was leaking.
A Snap-On Snap ring tool easily removed the snap ring from the top of the master cylinder. I give my wife a list of Xmas presents I would like each year and she picks some of them for presents. A set of Snap On snap ring tools was one of them.
After the snap ring is removed from the top of the master cylinder, you just pull on the rod and pull the whole intermal assembly out.
Only two o-rings show but there are two more hidden inside. Another small snap ring is at the far right of the assembly. When it is removed the rest of the assembly can be taken apart.
The small o-ring now shows in the picture below.
The fourth medium o-ring is hidden inside the assembly below. I had to use a dentists pick to remove it. You can see some black crud on the teflon washer in the picture below. There was a lot of black crud on most of the pieces and also in the brake fluid in the master cylinder. I wasnt sure what it was until a friend, Mike Taylor came by and said it was probably parts of the o-rings that were rubbed off or decomposing. This makes sense to me. Really happy that I decided to rebuild these cylinders.
A quick trip to the local parts chick (Aerozona Parts) and I returned with 8 o-rings. Each master cylinder took
1 MS28775-110
2 MS28775-112
1 MS28-775-113
After lubricating the o-rings with brake fluid, they were assembled in the reverse order and reinstalled on the aircraft.
The Vertical Power box of goodies was delivered friday afternoon to the airport. The switch panel was heavier that I was expecting. Must be a lot of gear inside it. Hopefully that means its tough and durable.
I had left the cutout for the switch panel on the instrument panel undersize until I had an actual switch panel to mate up to the panel. I spent about an hour with a file enlarging the panel to fit the switch panel.
The picture below shows the backside of the switch panel.
The next picture shows the backside from the pilot side which made me realize I had made a slight design miscalculation. The pilot side of the switch panel contains a telephone type jack for connection to a laptop for upgrades and saving/loading profiles. This side is only 1 inch from my radio stack which is going to make it really hard to get to. However, this turned out to not be a problem as the mounting bracket on the back of the switch panel can be turned by hand. Its really easy to put on and off. I will plan on just reaching up from below the panel and unscrewing the mounting bracket and pulling the switch panel out an inch and access the jack from the front of the panel, then reinstall it once the update is complete. Another idea is to just leave the connector that hooks to the laptop plugged in. ( http://katiesrv4.blogspot.com/2007/10/wiring-programming-cable-for-vp-100.html )
It has a 9 pin D sub connector serial port on the end that plugs into the laptop. Since the Dynons each have a serial connector to connect to the laptop, I now have 3 serial connectors on the RV-4. This is more than I have on my desktop computer at home!
Vertical power sent serial No. 3, so I definitely have one of the first units to beta test.
The accessories bag that came with the switch panel includes a cable to go between the switch panel and the control panel, a key fob that lets you turn the power to your aircraft on and off remotely as well as program other functions and a short antenna that I assume is for the control unit to receive the key fob transmissions.
Here is how the switch panel looks from the rear when it was installed in the panel.
I had to break off work to take my sweetheart out to Abuelos for some good Mexican cuisine.
Tomorrow I should be able to apply vertical power to my Dynons and start programming everything.
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