Flexibllity of Brake Lines on a Bumpy Grass Strip

SHORTRV7 · #1 10-09-2008, 09:27 PM

I am getting ready to run the brake lines on my -7 from the firewall down to the calipers. I live on a fairly bumpy (but not to bad) Grass Strip and wanted some of you to reflect on the flexibilithy and the duribility of the solid aluminum brake lines as the landing gear moves all around. Also, while I am on the subject is there any reason why I should put stiffeners on the gear legs like some did on the -6?????

SteinAir · #2 10-09-2008, 09:31 PM

#1, don't put the stiffners on the legs unless you find you need them. It was a much more prevalent need back when we all drilled our own gear legs, but now that they are pre-drilled it seems the need for stiffners is almost nill. I've had both, and my current flying plane doesn't have them.

#2, I also fly off of a pretty bump (worse than most) grass strip and have for over 10 years. We've now had a number of RV's we built flying off this strip and never have had a problem - tubes installed per Van's with the "loop" around the bottom of the axle. This through deep snow, catching a wheel pant on the tire, tall grass, and lots of other abuse....that being said, I have seen some of my customers with flexible lines and that seems fine too.

My 2 cents as usual!

Cheers,
Stein

rv7charlie · #3 10-09-2008, 10:02 PM

RV-4, ~800 hrs off gravel, some paved, lots of good grass. No problems with brake lines, minimal problems with shimmy, and only on pavement.

Charlie

Mel · #4 10-10-2008, 06:50 AM

My -6 has been flying 15.5 years with aluminum tubing from firewall to calipers (and I don't even have a full loop around the axle). I fly from many rough strips. Never had a problem.

vic syracuse · #5 10-10-2008, 08:21 AM

I think the weak point on the brake lines is at the top of the gear leg on the A models, where the bulkhead fitting enters the fuselage. I live on a grass stripp, but after about 400 hours, the right brake line on my RV-10 developed a leak at this point. Could have been caused by a lot of things---hard landing (not me, says the butler!), poorly made flare, etc. But just to be safe, I replaced both lines with the stainless flexible lines, and did the same on my RV-7A.

Vic