Brake Reservoir mounting holes

Working on the firewall (RV-7) and the plans 'Gotcha's' suggest initially not riveting the place where the brake reservoir lives as one or more rivets will just have to be drilled out later. Unfortunately that part is on backorder and the plans aren't clear (to me anyways) how far apart the mounting holes are and if either hole will take the place of an existing rivet.

Anyone have one sitting around and can measure the distance between mounting holes? Or is it really not an issue anyways?

The VA-107 reservoir is listed as being on all of the kits, so this is more of a generalized question vs -7 specific.

Thanks!

Two x 3/16" diameter holes on 2.00" centers. Drilling a rivet out after it has been set is not a big deal.

FlyGuy65 said:

Working on the firewall (RV-7) and the plans 'Gotcha's' suggest initially not riveting the place where the brake reservoir lives as one or more rivets will just have to be drilled out later. Unfortunately that part is on backorder and the plans aren't clear (to me anyways) how far apart the mounting holes are and if either hole will take the place of an existing rivet.

Anyone have one sitting around and can measure the distance between mounting holes? Or is it really not an issue anyways?

The VA-107 reservoir is listed as being on all of the kits, so this is more of a generalized question vs -7 specific.

Thanks!

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Highly recommend you install a Matco clear reservoir versus the solid Van's supplied one. MCR-100 or -100A (inverted) if you plan to do any negative G maneuvering. You can view the fluid level when checking the oil. Comes with a mounting bracket, as well.

Nothing wrong with the Vans reservoir, Van himself performed airshow aerobatics with it. Nothing wrong with the Matco one above either. Personally, I like the Grove 067-054 remote reservoir, but it is a bit more difficult to mount. Whatever you decide, drill the holes in the firewall after you have the reservoir in hand. I ended up with extra holes that I have to plug.

+1 to wait until you have the reservoir before drilling the holes. The Vans reservoir appears to be hand made so there may be some minor variation in the hole spacing.

I mounted it after riveting the firewall and it was no issue whatsoever to drill the 3/16 holes.

Good on you for reading ahead, but if you build it per print it doesn't pick up existing rivet holes. Drawing 19 shows the centerline of the reservoir 4 1/2" inbd of the upper starboard engine mount hole. That puts the outboard hole between rivet 3 and 4 on that row and the other hole between rivet 4 and 5.

Having said all that, I'll also share that, speaking from personal experience, its easy to give yourself analysis paralysis trying to get ahead of every detail. There are some things that yeah, by all means, it's easier to do it as early as possible (crotch strap anchors anyone?) But this one is pretty much a non event. It's no big deal to locate it later on, pretty much any time before you install the engine mount. Heck, there are al least 3 locations that make sense for locating that thing depending on which brake components and configuration you end up with.

If 6 months from now you decide you only want pilot brakes it makes a lot of sense to have it on the pilot side. If you decide you absolutely must have aftermarket Grove super brakes, you don't need it at all. Sometimes kicking the can on down the road and keeping your options open has unseen benefits.

I've started my RV-9 QB fuselage and the instructions show the firewall penetrations. My firewall has a bend along the upper rivet line such that if the reservoir is mounted along the rivet line the top of the reservoir hits the firewall. Does this bend get unbent at some point? I've deferred drilling the mounting and fitting penetrations until I understand how it's mounted. I'll use nutplates.

hoyden said:

I've started my RV-9 QB fuselage and the instructions show the firewall penetrations. My firewall has a bend along the upper rivet line such that if the reservoir is mounted along the rivet line the top of the reservoir hits the firewall. Does this bend get unbent at some point? I've deferred drilling the mounting and fitting penetrations until I understand how it's mounted. I'll use nutplates.

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Check the plans - there should be a note that states to place washers between the firewall and the reservoir mounting bracket to avoid contact between the top of the reservoir and the firewall.

Thanks for the heads up. The plans at this step don't address mounting the cylinder, only the firewall penetrations. As others have indicated the reservoir can be mounted later without issue. I won't do any drilling until I get to the step that actually mounts it. My RV-6 reservoir is mounted flush to the firewall without washers but that's probably is immaterial.

PaulvS said:

Check the plans - there should be a note that states to place washers between the firewall and the reservoir mounting bracket to avoid contact between the top of the reservoir and the firewall.

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