Is my Cleveland brake caliper torque plate installed backward?

[kenpilot]

Facts up front:
- RV-6A
- Rapco brake discs
- Cleveland 30-9 brake calipers
- Cleveland 66-106 brake linings

So I was down there yesterday troubleshooting a separate issue (chattering brakes after I ignorantly lubed up the anchor bolts with grease), and I noticed that the anchor bolts have a full 3/4" exposed. I don't know much about brakes, but if the purpose of the anchor bolts is to anchor the entire assembly -- provide some stabilizing effect -- it seems that 3/4" is quite a lot of distance. Who knows. So I started digging for some diagrams. Cleveland's manual (AWBCMM0001-12) has only one "example" diagram to explain what typical brake systems look like, but no diagram specific to the 30-9. That diagram shows a torque plate that is symmetrical, so I can't tell if "typically" the flange would point toward the cylinder or the opposite.

The only diagram I can find on Google that might be the 30-9 is the product image on the Aircraft Spruce website (see below). (But where did they get it, if Cleveland manual doesn't have it?? Even the filename of "500x5brake.jpg" doesn't lend a clue) The shape of my components looks exactly like the diagram, so let's assume it's accurate:


It appears that my torque plate is installed backward. The diagram shows the "flange" of the non-symmetrical torque plate (#17 in the diagram) facing the cylinder (#1); this means that much more of the anchor bolts (#4) are inside the "flange", providing the stabilizing effect.

Here's a picture of mine (LH and RH are both like this). My torque plate has the flange facing outboard away from the caliper, leaving a full 3/4" of exposed anchor bolt, and not much of it inside the flange.


Am I seeing this / understanding this correctly? Should I disassemble and flip it around?

 

[Walt]

Yep, it's backwards, pins should engage all the way.

 

[Stevea]

Yes, you should flip the torque plate around. You want as much of the guide pin supported as possible without the brake assembly bottoming out on the torque plate.

Also, grease on guide pins.....not good, because it attracts grit. If you look in the in the Cleveland maintenance manual....buried way back in appendix B, the recommended dry lube for the guide pins is called out:

Anchor Bolts/Torque Plate Bushings

Non-Amphibious Environment​

Silicone Spray​

Dri-Slide® Multi-Purpose Lubricant​

LPS Force 842® Dry Moly Lubricant​

 

[azrv6]

Attached PDF of Cleveland 30-9 exploded view and parts list from the Cleveland Master Parts List downloaded from their site many years ago:

 

[scard]

Wow, I didn't even realize that would work.

 

[kenpilot]

Attached PDF of Cleveland 30-9 exploded view and parts list from the Cleveland Master Parts List downloaded from their site many years ago:

Thank you, Dave. I'm so glad you had that! I'll put it in my product manuals folder.

Also, grease on guide pins.....not good, because it attracts grit.

Yep! That's what I had just found last night. Even worse, I had greased it all up good and was operating out of a dirt runway. Terrible idea. I'll get that fixed right away. Subject for another thread I'm sure.

Wow, I didn't even realize that would work.

My reaction too. I was very surprised to find a major certified component like this that could be installed the wrong direction and actually work. This airplane has been flying for 900 hours now, possibly like this the whole time.

 

[Mikeyb]

fix the brake line too.

 

[kenpilot]

fix the brake line too.

Yes, both sides are like that. But to fix it properly, I'd need to remake the entire rigid line, since it's supposed to spiral around, per the build plans. That'll be a project for the condition inspection.

 

[kenpilot]

I just realized... this could also explain why the brake linings I just removed were worn so much more on one end vs. the other. Not quite to the angle of a door stopper, but certainly more angled than I'd expect from a brake system. I bet the caliper has been rotating more than it should, due to the reduced depth of the anchor bolts.

 

[kenpilot]

One more note for anyone reading this in the future.... The link on Aircraft Spruce's page that is labeled "Click here to download the Cleveland Application Chart PDF" is actually a link to the full 296-page Illustrated Parts List from Cleveland. And that's exactly where Aircraft Spruce got that product image from. Duh. I didn't even think to click on that, because I wasn't looking for an "application chart".

Thanks, Dave, for the 1-pager. It helped a lot to know what Cleveland called the document: "AWBPC0001". With that important fact, I finally found the source document from Cleveland. As far as I can tell, they don't link directly to the PDF anywhere on their website:
https://www.parker.com/literature/A...AWB Static Files for Literature/AWBPC0001.pdf

In case that link is broken in the future, I found it like this (although not obvious in the search results): https://duckduckgo.com/?q=site:parker.com+AWBPC0001&t=ffab&ia=web.

 

[Stevea]

Here’s an FYI for future use. As of September 2022, Parker Aircraft Wheel & Brake was sold to Kaman Corporation. This means all the web page links to information on the Parker website (like those above) will probably break….if they haven’t already. Suggest looking on Kamans website for technical info.

Cleveland Wheel & Brake Systems – a Signia Aerospace Company

Performance That Goes the Distance Aircraft brake discs engineered for longer life Discover Obsidian Brake Discs

www.aircraftwheelandbrake.com

The tech info can be found on individual product pages for whatever brake or wheel assembly you’re looking for. Seems like the Parker tech info has been ported to the new site…..just located under different page headings than Parker had them. (Not how I’d arrange it…but they didn’t ask me. How about a “Technical Information” tab on the main page?……anyone?)

 

[azrv6]

More information than you asked for, but might be helpful in the future when you fix the pinch in the fluid lines. You'll need to replace the o-ring in the caliper, per the spec sheet it is a MS28775-218. Or, you could follow Van's SL-00047, linked here, and upgrade the caliper o-rings to the new super duper higher temp o-rings and MIL-PRF-83282 brake fluid.
Also, you more than likely have Cleveland 10-30 master cylinders on your rudder/brake pedals. You might rebuild them while you have the brake system apart. Easy to do. Spruce sells a kit (PN 06-01130) for a gazillion dollars when all you'll really need are the o-rings called for in the spec sheet attached. Have also attached the master cylinder rebuild instructions which are included with the kit.

 

[blaplante]

When I did my brake lines from the fuselage to the caliper I opted for getting custom made braided hoses from Summit racing (IIRC). No worries about kinking or stress cracks. Far cheaper than ACS, and given we don't have power brakes I'm not too concerned about the hydraulic pressure!