Brake lines?

Discussion in 'General Experimental Aviation Questions' started by Dana, Aug 28, 2017.

Help Support HomeBuiltAirplanes Forum by donating:

  1. Aug 28, 2017 #1

    Dana

    Dana

    Dana

    Super Moderator Staff Member

    Joined:
    Apr 4, 2007
    Messages:
    8,613
    Likes Received:
    3,002
    Location:
    CT, USA
    With the new landing gear on my Starduster being longer, I need to extend the brake lines. Never having owned a plane with "real" aircraft hydraulic brakes before, I'm a little uncertain on how to proceed.

    The new gear is air about 4" longer than the old. As it's a royal PITA to access where the existing brake lines attach to the parking brake valve, I'd like to extend the existing lines with a short (4-8") additional piece. Ideally I'd like to get a length of braided hose with a male fitting on one end and a female on the other. What I have now, I presume, are AN fittings in -4 size (judging by the 4-4 stamped on the hose end)?

    It would also make sense to change the 90° elbow on the caliper to a 45° one (the other side already has a 45° elbow).

    IMG_20170827_161445865_HDR.jpg

    Dana
     
  2. Aug 28, 2017 #2

    Dan Thomas

    Dan Thomas

    Dan Thomas

    Well-Known Member

    Joined:
    Sep 18, 2008
    Messages:
    4,855
    Likes Received:
    2,070
    You could make up a couple of 1/4" aluminum lines from 5052-O .035" wall tubing and run them between the park brake valve and the flex hose. Four nuts and sleeves and two flare unions.
     
  3. Aug 28, 2017 #3

    Dana

    Dana

    Dana

    Super Moderator Staff Member

    Joined:
    Apr 4, 2007
    Messages:
    8,613
    Likes Received:
    3,002
    Location:
    CT, USA
    If I could easily access the upper end of the hoses at the parking brake valve I'd just replace the entire hose. As it is, any extension needs to go on the lower end. A hard line would be fine, but I don't have a 37° flaring tool, just the standard 45° automotive one.

    Dana
     
  4. Aug 28, 2017 #4

    Hot Wings

    Hot Wings

    Hot Wings

    Well-Known Member HBA Supporter

    Joined:
    Nov 14, 2009
    Messages:
    6,365
    Likes Received:
    2,298
    Location:
    Rocky Mountains
    Double check with the local auto parts store. They may not stock the cheepe 37 deg tool but they should be able to order one. For $25 it will be a single flare type, not the double. If your comfortable with a single flare then this might be an option?
     
  5. Aug 28, 2017 #5

    lathropdad

    lathropdad

    lathropdad

    Well-Known Member

    Joined:
    Sep 13, 2007
    Messages:
    47
    Likes Received:
    18
    Location:
    Indiana
    I would advise against using an aluminum tube to extend the brake line. I think the risk of the tube failing over time is much too high.

    I would suggest that you get short -4 braided lines made with male and female ends. I also would recommend that you use crimped fittings instead of reusable fittings because the crimped are less bulky.

    Here is one shop that you can get these extensions made; http://www.earlsindy.com
     
  6. Aug 28, 2017 #6

    BBerson

    BBerson

    BBerson

    Well-Known Member HBA Supporter

    Joined:
    Dec 16, 2007
    Messages:
    12,014
    Likes Received:
    2,340
    Location:
    Port Townsend WA
    Terminate the existing hose to a nice clamp on the back of the steel tube. Then run a 12" flex hose to the caliper.
    A 1/4" X 4" black pipe or brass nipple in the caliper would work temporarily.
     
  7. Aug 28, 2017 #7

    Hot Wings

    Hot Wings

    Hot Wings

    Well-Known Member HBA Supporter

    Joined:
    Nov 14, 2009
    Messages:
    6,365
    Likes Received:
    2,298
    Location:
    Rocky Mountains
    Good thought! Most any equipment hydraulics shop should be able to fabricate the hoses while you wait. Just let them know what kind of fluid so they can pick a hose material that is chemically compatible. They should also have 45 deg and 90 deg fittings in their stock.
     
  8. Aug 28, 2017 #8

    Dana

    Dana

    Dana

    Super Moderator Staff Member

    Joined:
    Apr 4, 2007
    Messages:
    8,613
    Likes Received:
    3,002
    Location:
    CT, USA
    Yes, that's the direction I'm leaning in now. I was thinking hard line because I don't need 12" (the shortest premade flex line I can get), but it just looks easier. And Summit Racing has 12" Aeroquip hoses with -4 AN ends in stock for only $8.00... just need to verify the size before ordering.

    Dana
     
  9. Aug 28, 2017 #9

    BJC

    BJC

    BJC

    Well-Known Member

    Joined:
    Oct 7, 2013
    Messages:
    9,527
    Likes Received:
    6,305
    Location:
    97FL, Florida, USA
    FWIW: A friend built an award winning Pitts Model 12 with "Aeroquip fuel hose and fittings" from Summit Racing. After the first flight, he replaced them all due to leaks. That was his fifth or sixth homebuilt, and he had previously restored / rebuilt a dozen or so certificated airplanes.


    BJC
     
  10. Aug 28, 2017 #10

    Pops

    Pops

    Pops

    Well-Known Member

    Joined:
    Jan 1, 2013
    Messages:
    7,115
    Likes Received:
    6,013
    Location:
    USA.
    There is an Aeroquip dealer about 25 miles away from me. They will make about anything you want. I even bought about 20' of Aeroquip SS hose at a surplus military place at $1 a foot and took the hose to the Aeroquip dealer to make up hoses that I needed, no problem. Really nice people. One Sat after store hours a hose broke on the Backhoe/endloader and they opened the store to make me a new hose.
    Any local dealers in your area?
     
  11. Aug 28, 2017 #11

    rv6ejguy

    rv6ejguy

    rv6ejguy

    Well-Known Member

    Joined:
    Jun 26, 2012
    Messages:
    3,749
    Likes Received:
    2,788
    Location:
    Calgary, Alberta, Canada
    Earls makes prefabbed -3 and -4 lines in a variety of lengths starting at 6 inches and with different ends. Inexpensive and pressure tested to 4000 psi.
     
  12. Aug 28, 2017 #12

    Dana

    Dana

    Dana

    Super Moderator Staff Member

    Joined:
    Apr 4, 2007
    Messages:
    8,613
    Likes Received:
    3,002
    Location:
    CT, USA
    Well Brian, I hope your friend's case was an isolated incident, I already ordered them from Summit. We'll see how it goes.

    Dana
     
  13. Aug 28, 2017 #13

    BJC

    BJC

    BJC

    Well-Known Member

    Joined:
    Oct 7, 2013
    Messages:
    9,527
    Likes Received:
    6,305
    Location:
    97FL, Florida, USA
    He used them for the cost savings. They were recommended by another builder who, apparently, had no problems. Hope yours are in the "no problems" category.


    BJC
     
  14. Aug 29, 2017 #14

    Toobuilder

    Toobuilder

    Toobuilder

    Well-Known Member

    Joined:
    Jan 20, 2010
    Messages:
    4,431
    Likes Received:
    3,234
    Location:
    Mojave, Ca
    Considering the light weight of the SD-1, I'd be very tempted to simply run 3/16 plastic tubing and compression fittings. Van himself once endorsed the scheme, and though he's moved away from that now, there are still a LOT of RV's so equipped.

    I have recently plumbed the Rocket with 1/8 stainless hard line and compression fittings. Light, inexpensive, and theoretically durable, that might be an option to consider as well.

    [​IMG]
     

Share This Page

arrow_white