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Brake Flange Bolt Pattern

00Dan

Well Known Member
I ran into a snag fitting my new wheel pants today. When I went to install the U-810 fairing bracket I discovered the bolt pattern on the 80’s vintage U-403 brake flange are different. I’ve attached pictures below.

Talking to Van’s their thought was to order a new U-403 and hope they can be made to fit (was there an axle diameter change?). The mothership wasn’t fond of any method involving less than 3 fasteners on the U-810.

Anyone have some ideas on alternate paths forward to fit this? One hole lines up and I could perhaps drill a second in the fairing flange, but edge distance with one of the three prepunched holes may be an issue. The third hole doesn’t line up with anything.

I don’t have the ability to weld so that’s not my first choice for how to proceed.
 

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I went through the same thing. You do want a new U-403. The axle diameter is the same however the location of the holes to mount it to that axle are different.

The new 403 bracket should make everything work as it is supposed to.
 
I went through the same thing. You do want a new U-403. The axle diameter is the same however the location of the holes to mount it to that axle are different.

The new 403 bracket should make everything work as it is supposed to.

In that case seems I have some parts to order. The builder of my plane drilled the original flange on the opposite side, I imagine I’ll be able to play with the axle spacers to make it all work.
 
Follow up question: I got the new parts in and the old flanges are positively seized on. Both Kroil and attacking it with a torch had no effect. Any suggestions for removal? I don’t need to reuse them but I’m not sure if any destructive techniques are viable given the axle underneath it.
 
That I didn't have to deal with, mine were tight but not unmanageable.

You might try a cut off wheel making sure not to go too deep and score the axle.
 
You can consider a doubler of the same thickness for the lower potion of the pant bracket. Cut it to size using the original as a pattern. Place the doubler on the axle bracket and match drill the holes. attach doubler to pant bracket and enlarge holes to match doubler (can match drill only if carefull to avoid bit wandering that would hog out the final hole) and rivet it on.

Been a while since I did these, so don't know if there are any space limitations that would prevent the extra thickness in the doubled area. Looking at your pics, it looks like that is what the original builder did, though I would have made the doubler bigger than that, if space allowed.

grinding away the bracket can be dangerous if you are not experienced in that approach. You don't want to cut a groove in your axle. Very doable, but easy to go too far. You only grind to get the bracket thin, NOT all the way through, then tap with a hammer to make it fracture.
Larry
 
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You can consider a doubler of the same thickness for the lower potion of the pant bracket. Cut it to size using the original as a pattern. Place the doubler on the axle bracket and match drill the holes. attach doubler to pant bracket and enlarge holes to match doubler (can match drill only if carefull to avoid bit wandering that would hog out the final hole) and rivet it on.

Been a while since I did these, so don't know if there are any space limitations that would prevent the extra thickness in the doubled area. Looking at your pics, it looks like that is what the original builder did, though I would have made the doubler bigger than that, if space allowed.

grinding away the bracket can be dangerous if you are not experienced in that approach. You don't want to cut a groove in your axle. Very doable, but easy to go too far. You only grind to get the bracket thin, NOT all the way through, then tap with a hammer to make it fracture.
Larry

I’ve passed the point of no return on attempting to reuse the old brackets; the flange started to deform while the sleeve stayed put. For the reasons you stated, grinding it off is a last resort. The plan today is to attempt to heat it with a MAP gas torch (I used propane yesterday) and see if a big pipe wrench can be used to break it loose.

The other idea I had was to attempt to fabricate a plate that I could bolt to the flange and use with a slide hammer.
 
There is a cross bolt hole, right? Can't see it in the photo.
I would rig up a puller to put tension on the bracket and then tap/heat/tap to break it loose if frozen on. Or maybe even an impact hammer with a pickle fork to go around the axle and get both sides of the flange.
 
Another method would be to use a center punch & peen a series of lines to stretch the sleeve. Avoid hitting too hard & damaging the spindle.
 
Anyone have some ideas on alternate paths forward to fit this?

Maybe I'm missing something, but it can't be more than a few hours to fabricate two new U-810's with a custom bolt pattern. Just copy them, and move the mount holes.
 
Maybe I'm missing something, but it can't be more than a few hours to fabricate two new U-810's with a custom bolt pattern. Just copy them, and move the mount holes.

That would make sense, but I’m not as smart (or skilled) as you!

I was able to get the old U-403s off finally by putting a MAP gas torch to it and turn using a tie rod fork in the rivet gun to knock it off.
 
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