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Accessory case hydraulic drive pad accessible?

digidocs

Well Known Member
Hi there,

Does anyone know if the hydraulic pump drive pad on the back of the accessory case is accessible when installed in the -10? I can't find a great picture, but it appears that it may be blocked by part of the engine mount.

Thanks for the help,
David
 
Vac pad?

If you mean the mounting location for the vacuum pump, upper rear right, then yes it's accessible. Shown here during FWF install:
RV102168.jpg

That's where I have my FS1 backup alternator and it fits fine.
 
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IIRC there's nothing blocking it, but I'd have to go out to the hangar to be sure. For those following along at home, the hydraulic pad is below the right mag and to the right of the fuel pump (when viewing the engine from the cockpit).
 
Not vacuum

IIRC there's nothing blocking it, but I'd have to go out to the hangar to be sure. For those following along at home, the hydraulic pad is below the right mag and to the right of the fuel pump (when viewing the engine from the cockpit).

Ahh, so not the vacuum pad.
 
Yes, it's accessible. Here I removed the cap on the side of the pad for a Air/Oil return line, but the pad face is accessible when mounted.

WP_20130126_002_zps45be53a9.jpg
 
Guys,

Thanks a bunch for the information and pictures. It looks like it would be possible to mount something down there.

No rush, but if its convenient it would be interesting to know how many inches of distance are available before hitting the firewall.

Thanks again,
David
 
On a 540, the governor pad is on the front of the engine. We're talking about the hydraulic pump drive pad (not often used on RVs) which is next to the mechanical fuel pump, below the mags.

David
 
Wanted to see if a standby alternator like the FS1 would fit down there.
This begs another question, why do you want to mount it there when everyone else mounts it on the unused vacuum pad,
just like in the picture Post#2?
 
David,
I just took some measurements. On my install (I have a C4B5) the hydro pad is mostly over the firewall recess, but it is close to the bottom and right hand edges of the recess (as viewed form the cockpit). As such it's 9-3/16" from the back of the recess to the face of the cover plate on the pad. The distance to the the firewall proper is 7-1/8". I also have the FS-1 on my vacuum pad and your comment about potentially mounting someting like it on the hydro pad prompted me to also measure the distance between studs and they aren't the same. The vacuum pad studs are 1-3/4" apart while the studs on the hydro pad are 2" apart.
 
Todd,

You're a true gentleman. Thank you!
As you discovered, there is an adapter required.

Ernst---I *am* going to have AC on my ship and trying to evaluate options that avoid the mess of the compressor and alternator both on the front.
 
David,

To actually use the hydraulic pad you need the drive assembly which has the gear and housing - similar to the vacuum pad. That drive assembly makes the actual mounting surface about 2" further aft.

Years ago I looked at putting a B&C SD-20 there but there wasn't room after factoring in the drive assembly. That was in the early days of RV-10s before B&C came out with the SD-20 spacer and new shear coupling to allow their angled oil filter adapter (with required spacer) to co-exist.

Bob
 
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