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  #1  
Old 06-16-2021, 04:58 PM
00Dan 00Dan is offline
 
Join Date: Nov 2016
Location: Atlanta, GA
Posts: 222
Default Brake Flange Bolt Pattern

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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Last edited by 00Dan : 06-16-2021 at 06:50 PM.
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  #2  
Old 06-16-2021, 11:53 PM
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Nick Nick is offline
 
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Location: Rosharon, TX
Posts: 177
Default

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.
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91TS Rosharon, TX
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  #3  
Old 06-17-2021, 08:45 AM
00Dan 00Dan is offline
 
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Location: Atlanta, GA
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Quote:
Originally Posted by Nick View Post
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 Iíll be able to play with the axle spacers to make it all work.
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  #4  
Old 06-23-2021, 01:24 PM
00Dan 00Dan is offline
 
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Location: Atlanta, GA
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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 donít need to reuse them but Iím not sure if any destructive techniques are viable given the axle underneath it.
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  #5  
Old 06-23-2021, 10:15 PM
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Nick Nick is offline
 
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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.
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91TS Rosharon, TX
RV-4 Bought 2019, Day to Day Restoration while still flying. SDS EFI IO-360, Hartzell CS, DanH inspired custom intake, G3x Panel
RV-8 SB, "Back burner project."
RV-10 Built 2010, Sold 2019
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  #6  
Old 06-24-2021, 07:05 AM
lr172 lr172 is offline
 
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Location: Schaumburg, IL
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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
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Last edited by lr172 : 06-24-2021 at 07:17 AM.
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  #7  
Old 06-24-2021, 07:58 AM
00Dan 00Dan is offline
 
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Location: Atlanta, GA
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Quote:
Originally Posted by lr172 View Post
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
Iíve 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.
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  #8  
Old 06-24-2021, 08:22 AM
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fl-mike fl-mike is offline
 
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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.
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  #9  
Old 06-24-2021, 08:57 AM
Ralph Inkster Ralph Inkster is offline
 
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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.
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  #10  
Old 06-24-2021, 10:04 AM
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DanH DanH is offline
 
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Quote:
Originally Posted by 00Dan View Post
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.
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