News: Added Links For Twin Commander and Facebook Pages

Login  |  Register

Author Topic: Fuel leaking along both left and right main fuel lines.  (Read 2789 times)

lesnagy

  • Newbie
  • *
  • Posts: 28
64 AC 500B

I have a bazaar fuel leak issue. First off the fix is to replace the main fuel lines from the boost pump to the fuel strainers. Its hard to believe what I am seeing so I need to ask.
When The boost pump is on left or right side the main fuel line rapidly sweats out fuel as if the tube is full of holes as seen from top inspection panels just in front of the inboard flaps . I see the tube bulge under the pressure of the boost pump then the fuel starts flowing all along the main line. When the boost pumps are off the lines don't leak. I plan to replace all the lines but find it hard to believe that this MIL spec tube can leak uniformly down the length of the line. Anyone see anything like this before? Also any good things to know prior to replacing these lines? I see the maint manual states that the boost pressure should be 24 PSI. I am thinking it may be way higher than that and that is what eventually failed the lines.

Thx,
Les

Bruce Byerly

  • Hero Member
  • *****
  • Posts: 761
Re: Fuel leaking along both left and right main fuel lines.
« Reply #1 on: May 19, 2018, 11:31:35 pm »
Les -  many of these planes I see have their original flex fuel lines. You can do chin ups on these ďflex linesĒ they are so stiff.  They are petrified.  Mil spec or not, if the lines are no longer flexible, they are junk. IMHO they should be replaced every 10 years. Once you cut them to get them out, look at the inside. Iíve seen them literally falling apart. You may want to look at all the lines in the plane.

lesnagy

  • Newbie
  • *
  • Posts: 28
Re: Fuel leaking along both left and right main fuel lines.
« Reply #2 on: May 20, 2018, 12:59:21 am »
Bruce, Understood. I just assumed that the USFS would have changed out these lines many times in its life but that may or may not be the case. I will go through all flex lines and change them out just so I know they are new under my watch. :)

les

Bruce Byerly

  • Hero Member
  • *****
  • Posts: 761
Re: Fuel leaking along both left and right main fuel lines.
« Reply #3 on: May 20, 2018, 04:20:09 pm »
Bruce, Understood. I just assumed that the USFS would have changed out these lines many times in its life but that may or may not be the case. I will go through all flex lines and change them out just so I know they are new under my watch. :)

les

Les, I would assume absolutely nothing based on the fact that it was owned or operated with an entity in any way connected to the US government.  Just remember, the FAA doesnít subject itís own planes to the AW requirements you and I have to abide by.  Once in a while you get happy open taxpayer checkbook surprises but other times itís a disaster.

lesnagy

  • Newbie
  • *
  • Posts: 28
Re: Fuel leaking along both left and right main fuel lines.
« Reply #4 on: May 21, 2018, 02:00:21 am »
Bruce, So far what I can see hords of money have been spent on this plane. I am more than ok to change out the $300 fuel lines. I think I have been lucky so far. :)

Bruce Byerly

  • Hero Member
  • *****
  • Posts: 761
Re: Fuel leaking along both left and right main fuel lines.
« Reply #5 on: May 22, 2018, 01:41:46 am »
Bruce, So far what I can see hords of money have been spent on this plane. I am more than ok to change out the $300 fuel lines. I think I have been lucky so far. :)

Well Les, donít feel alone, the one I just bought needs them too. I wish I could do it for $300 though!

Having one thatís had some care and feeding is always a plus.  I didnít  mean to be dismissive regarding the history, just caution assuming itís been done right previously and/or doesnít need to be done again.

lesnagy

  • Newbie
  • *
  • Posts: 28
Re: Fuel leaking along both left and right main fuel lines.
« Reply #6 on: May 22, 2018, 02:02:29 am »
Bruce, So far what I can see hords of money have been spent on this plane. I am more than ok to change out the $300 fuel lines. I think I have been lucky so far. :)

Well Les, donít feel alone, the one I just bought needs them too. I wish I could do it for $300 though!

Having one thatís had some care and feeding is always a plus.  I didnít  mean to be dismissive regarding the history, just caution assuming itís been done right previously and/or doesnít need to be done again.


no worries. Looks like these lines will be easy to replace. I will post an update once its done.
Thx for the input.
Les

lesnagy

  • Newbie
  • *
  • Posts: 28
Re: Fuel leaking along both left and right main fuel lines.
« Reply #7 on: June 04, 2018, 03:06:20 am »
64 AC 500B

I have a bazaar fuel leak issue. First off the fix is to replace the main fuel lines from the boost pump to the fuel strainers. Its hard to believe what I am seeing so I need to ask.
When The boost pump is on left or right side the main fuel line rapidly sweats out fuel as if the tube is full of holes as seen from top inspection panels just in front of the inboard flaps . I see the tube bulge under the pressure of the boost pump then the fuel starts flowing all along the main line. When the boost pumps are off the lines don't leak. I plan to replace all the lines but find it hard to believe that this MIL spec tube can leak uniformly down the length of the line. Anyone see anything like this before? Also any good things to know prior to replacing these lines? I see the maint manual states that the boost pressure should be 24 PSI. I am thinking it may be way higher than that and that is what eventually failed the lines.

Thx,
Les

Fuel lines all swapped out. It took a few hours but was fairly easy to do solo. So nice to turn on the boost pumps and not have fuel leaking out. :)

Badger

  • Full Member
  • ***
  • Posts: 228
Re: Fuel leaking along both left and right main fuel lines.
« Reply #8 on: June 04, 2018, 09:32:18 am »
Sounds like a great fix!

Your 500B is a '64 model, too?  I love mine!

ed
Ed

SKYFLYER

  • Administrator
  • Hero Member
  • *****
  • Posts: 544
Re: Fuel leaking along both left and right main fuel lines.
« Reply #9 on: June 04, 2018, 11:19:52 am »
It is ALWAYS a good thing to NOT have fuel leaking out 8)

Good you got it worked out.