Uncommanded Parking Brake Activation

[andy]

Does anyone have a rough idea of how much it would cost or how many hours it would take to replace the tab type parking brake with the hydraulic parking brake in drawing 9117E?

[Hale-Yes]

PM Sent

[Old Piper]

Pls. Share the estimated time and materials. This is one feature I would like to add.

Thanks
Tom

[gbarrier]

If Maule can supply the hoses, bracket and valve, etc. as a kit that would probably be best way to buy it all. Has anyone priced this from Maule?

Still have to weld the bracket and tab to the tubes. My compass hates me every time i weld on the frame. Could probably use a couple of adel clamps but then you are not in compliance with the drawing. Looks like something best done at annual when floorboards are already out at best.

[crbnunit]

A kit would definitely be nice. One stop shopping and no fab except the bracket. Dwayne?

[1:1 Scale]

I've got my plane down to the frame and looked into adding the hydraulic parking brake. I spoke with someone at Maule (I forget who it was, but maybe Brian or Duane?), and they said they had either never seen one, or only a VERY limited number.

I couldn't find the specified valve either, which is what prompted the call, so I'm not installing one.

[Andy Young]

That valve is either identical or very similar to the one installed stock on Citabrias and Scouts. I’d call American Champion and ask them.

[ajak]

Guess this is an old post, but wondering if anyone has any newer experience on how involved it is converting the old tabbed parking brakes to the hydraulic ones (Drawing # 9117E)? I am currently highly motivated after an incident the other day where one of the tabs wouldn't release after landing and parking on a steep sloped backcountry strip. Apparently it wasn't a particularly confidence inspiring experience for my wife who was watching me lying upside down working on disconnecting the tab far off the grid with clouds starting to roll in.

[Andy Young]

Asa to the white courtesy phone…

[asa]

Guess this is an old post, but wondering if anyone has any newer experience on how involved it is converting the old tabbed parking brakes to the hydraulic ones (Drawing # 9117E)? I am currently highly motivated after an incident the other day where one of the tabs wouldn't release after landing and parking on a steep sloped backcountry strip. Apparently it wasn't a particularly confidence inspiring experience for my wife who was watching me lying upside down working on disconnecting the tab far off the grid with clouds starting to roll in.

I did it during my m6 rebuild and it works perfectly. Here’s the process overall.

- Source the hydraulic valve

- Remove current parking brake tabs, cable/spring, etc

- Weld up valve bracket per drawing

- Weld bracket onto airframe per drawing

- Build new brake lines to go from the cylinders to valve to landing gear. Requires new routing and may interfere with heater scat depending on your config.

- install/rig new push/pull control to operate the valve.


It would be a huge hassle to do the welding and hose routing and such with the airplane assembled but could be done I imagine. I did mine on a bare airframe. Personally I’d just delete your current parking brake and not bother with the hydraulic unless you’re pulling the plane apart for a recover or something.

[whittakerw]

I'm adding one also, had a hard time finding the valve. Ended up finding one through a several year old post on the Citabria forum. I bought one this spring, imagine he still has one more.

Here's a link to the forum topic- https://champcitabriadecathlonforums.co ... s-fs.1119/

[Otis]

I'm in the process of recovering my '78 M5 and have been looking at parking brake options. The Gerdes A-850-1 hydraulic valve is increasingly hard to come by that is listed in drawing 9117E. According to American Champion, Cleveland p/n 60-5 is supposedly a direct replacement ($1244 Aircraft Spruce), and he believed Grove had a similar valve that was very close if not a direct replacement. ($399 Grove, part number 068-004 probably) I asked Maule what new Maule aircraft come with for a parking brake, and they referred me to drawing 3183B. The current version of that drawing in the Veryon online parts catalog (Rev C) shows the original style parking brake with the Gerdes or Scott master cylinders. It turns out their is a Rev E from 8 May 2012 that shows Grove p/n 676-10 master cylinders that are designed with the integral parking brake tabs with a larger shaft. Maule claims that they have not heard of any problems with the parking brakes on the new master cylinder.
The hydraulic valve is clearly a better engineering solution, but it looks like it requires an E/A if you can't find a Gerdes valve. Has anyone heard of any parking brake problems with the new Grove master cylinders? Sorry for the long post.