Home > VansAirForceForums

- Donate yearly (please).
- Advertise in here!

- Today's Posts | Insert Pics

Go Back   VAF Forums > Model Specific > RV-8/8A
Register FAQ Members List Calendar Search Today's Posts Mark Forums Read

Thread Tools Search this Thread Display Modes
Old 12-03-2019, 08:15 PM
PilotjohnS PilotjohnS is offline
Join Date: Jan 2016
Location: Southwest
Posts: 777
Default Ferrule position

I think it is important that the brass ferrule is not too far onto the plastic tube. Both sides of the ferrule must contact the fitting. If the brass ferrule is too far on the plastic tube, then only one side seals against the fitting. So I would make sure the ferrules are sealing on both sides.
John S

WARNING! Information presented in this post is my opinion. All users of info have sole responsibility for determining accuracy or suitability for their use.

Dues paid 2019, worth every penny

RV9A- Status: tail feathers done less tips
Wings done less tips and avionics
Fuselage 30%
Reply With Quote
Old 12-04-2019, 05:47 AM
fixnflyguy fixnflyguy is offline
Join Date: Jan 2006
Location: Winston-Salem, N.C.
Posts: 1,047
Default I made the Braided SS switch..

I was a huge fan of the plastic lines when I built my -4 because they were simple, light and easy to DIY the length and routing. However, after 10 years of service, I found myself continually tightening, snipping and re-furreling the ends to keep from having leaks ,mostly at the high pressure caliper end. The final straw to the demise of my plastic lines was loosing my left brake on the departure taxi from OSH this year (made it back to NC with just the right brake). I have switched over to all SS braided AN fitting lines, and hope to never have any more issues. I never did have any leaking of the low pressure side, but mine were all plastic fittings as well as lines (no brass other than the ferrule. I believe time, temperature and other environmental subjection take a toll on plastic system and eventually they become BER.
Bill E.
8A7 / Advance NC
Reply With Quote
Old 12-04-2019, 08:35 AM
airguy's Avatar
airguy airguy is offline
Join Date: Oct 2006
Location: Garden City, Tx
Posts: 4,768

After 2 years of futzing around with the plastic lines in my 9A trying to resolve the same persistent leak, I gave up and had Tom make me a set of real hoses for replacement. No problems since. The plastic line and ferrule setup is not a good material choice for that application, IMHO.
Greg Niehues - PPSEL, IFR, Repairman Cert.
Garden City, TX VAF 2019 dues paid
N16GN flying 500 hrs and counting! Built an off-plan 9A with too much fuel and too much HP. Should drop dead any minute now.
Reply With Quote
Old 12-04-2019, 10:28 AM
skylor's Avatar
skylor skylor is offline
Join Date: Aug 2009
Location: Southern California
Posts: 723
Default Plastic Lines

I am one that has had leak-free plastic tubes in 860 hours of airframe time.

I think much of the success of getting these to be leak free depends on ensuring that the ends of the tubes are cut very straight and also ensuring that the tubing, ferrule, and fittings are clean and scratch/nick free prior to assembly. In my opinion, throwing braided noses I place of the small diameter very low pressure side of the system just adds unnecessary weight and cost to our aircraft.

Reply With Quote
Old 12-04-2019, 10:52 AM
Warden Warden is offline
Join Date: Nov 2013
Location: Mid Michigan
Posts: 17
Default Tubing Size

Make sure the tubing is 1/4" O.D. and not 6mm. Sometime a supplier will substitute 6mm (.236") for 1/4"! I've had this happen to me with industrial equipment. Just a thought.
Reply With Quote
Old Today, 11:48 AM
rv8ch's Avatar
rv8ch rv8ch is online now
Join Date: Feb 2005
Location: LSGG
Posts: 2,610
Default Fixed

Thanks for all the hints about how to solve this - really good info in this thread.

The way I solved it was to use the Steinair plastic tubing cutting tool to make a perfectly straight and perpendicular cut on the tubing, clean everything very well, and put it back together carefully. Seems to be holding now, I'll of course keep an eye on it over the coming days to make sure it's holding.

Mickey Coggins
"Hello, world!"
Reply With Quote

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

All times are GMT -6. The time now is 11:50 AM.

The VAFForums come to you courtesy Delta Romeo, LLC. By viewing and participating in them you agree to build your plane using standardized methods and practices and to fly it safely and in accordance with the laws governing the country you are located in.