Removing Wheel Extenders

[6643]

A.E.R.O. has a hose shop and I used to have them make up hoses for the kits I supplied through my parts business. For one-off hoses any well equipped maintenance shop should be able to make them up for you.

The hose in the photo looks like an automotive part. Be aware that automotive flares are not at the same angle as aircraft (45 degrees vs. 37 degrees.)

I checked the Cleveland documentation and did not find a drawing showing the flexible hose, in fact, all I found was a reference to shortening the hard line to accommodate the flexible line. I'm pretty sure the documentation Cleveland supplied for the Ercoupe conversion included a drawing showing the flexible line, but maybe it's just my oldtimers disease...

[8359]

Can someone help me source the right fittings/line to use for this? From browsing aircraft spruce it looks like using the Nylo-Seal line is a good option. I just need the fittings that screw into the top of the caliper, then whatever I would use to butt the nylo-seal and hard line together.

Thanks in advance.

[6643]

I don't think you'll get away with that on a certificated aircraft. I'd use Aeroquip 303 hose and 491 fittings.

[8359]

Thanks John. I guess that's where my newness shows, I just don't know what to search for. The 303/491 lines weren't listed under brake lines on ACS.

[5422]

Not that expensive and pretty easy to build those hoses out of stratoflex 111 and aeroquip 491 fittings. A #4 mandrel is about 30 bucks?

[8359]

^Thanks for the Stratoflex 111 suggestion, I'll look into as an alternate.

I want to verify my parts list. The part number on my brakes is pretty faded, it's hard to read (photo attached). From what I can tell the part number appears to be 3X-75B. The closest match in the Cleveland/Parker Parts Catalog is 30-75B. On page 4-16 (pg102) it visually looks like my brake caliper. The elbow I'm looking for is item #15 is listed as MS20822-4D. When I search that on ACS, it tells me that the thread is 1/8" thread (link).

Moving onto the Aeroquip 303/491 hose/fittings. The -3 is listed as for 3/16" tubing and the -4 is listed as for 1/4" tubing. When I look at the 491 fittings, -3 lists 3/8-24 thread and -4 lists 7/16-20 thread, neither of which are 1/8" thread like the MS20822-4D elbow. Do I order either one and just get an adapter? Are they not referring to the same thread? The datasheet from Eaton doesn't list any more details about the 303/491.

Aeroquip 303
Aeroquip 491
Aeroquip Datasheet

Any help?

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[6643]

Darned engineers...

The 1/8" thread is a (tapered) pipe thread. (1/8" (ID) pipe.) This is what screws into the brake housing.

MS20822-4 is 1/8" pipe on one end and 7/16-20 on the flared end. (You might want to use a MS20823, which is a 45 degree elbow, so you don't have to bend the hose a full 90 degrees.)

The Aeroquip 491-4 hose end mates with the MS20802X-4 fittings (and -4 hose.)

You'll need to shorten the hard line, re-flare (37 degree flare, not automotive!) and use an AN815-4 union to mate the flare to the hose.

[Edit] I'm guessing you were planning to have the hose run horizontally as in the photo posted earlier. I would cut the hard line on the vertical section and install the hose with a 45 degree bend to the caliper so the caliper floating is flexing the hose along the bend instead of lengthwise. (I don't think I explained that well. Look at AC43.13-1b Chapter 9.)

[8359]

Darned engineers...

Ha, point taken.

The 1/8" thread is a (tapered) pipe thread. (1/8" (ID) pipe.) This is what screws into the brake housing.

MS20822-4 is 1/8" pipe on one end and 7/16-20 on the flared end. (You might want to use a MS20823, which is a 45 degree elbow, so you don't have to bend the hose a full 90 degrees.)

The Aeroquip 491-4 hose end mates with the MS20802X-4 fittings (and -4 hose.)

You'll need to shorten the hard line, re-flare (37 degree flare, not automotive!) and use an AN815-4 union to mate the flare to the hose.

[Edit] I'm guessing you were planning to have the hose run horizontally as in the photo posted earlier. I would cut the hard line on the vertical section and install the hose with a 45 degree bend to the caliper so the caliper floating is flexing the hose along the bend instead of lengthwise. (I don't think I explained that well. Look at AC43.13-1b Chapter 9.)

John as always thanks for the details. Making my life a lot easier, and I'm learning along the way.

My plan was to cut on the vertical under the step on the gear leg, then route down to the caliper on the under side of the gear leg.

I believe I understand what you're trying to say. Are you saying put a 90 elbow on the caliper and a 45 elbow on the vertical/hard line? Or a straight out on the vertical and the 45 on the caliper? The line will be 12-15 inches, so I don't think there will end up being excessive bend radii (per chapter 9 of AC43.13).

[6643]

I can't explain it... I'll try to get out to the hangar in the next couple of days and take a picture. The hard line is cut on the vertical section above the bend at the bottom of the gear leg and the 45 goes on the brake housing. The hose goes from vertical (not really since the gear leg is not vertical) to 45 degrees. Sort of like the photo in post 2, but cut the hard line a little farther up and attach the hose to the hard line with a straight fitting, then change the 90 on the brake housing to a 45. Clear?

Now that I think about it, my brakes are on the back side of the wheels, but the same ideas apply. The 90 might work better, though, in your case.

OBTW, the OD of 1/8" pipe thread is about .400", almost the same as the 7/16" straight thread on the other end of the fitting.

[V529]

I believe that this is about what John is trying to describe. I found a yellow airplane so it would be as close as possible to what you have.

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