[mburch]

Hi folks,

I've deviated from the plans a bit by using Aeroquip hoses throughout the cockpit brake system of my RV-7, instead of the nylon tubing (based on the experience of having cracks and leaks in the plastic stuff on my last RV). Here's a photo of the connection from the brake reservoir down to the passenger's brake cylinders:



These are -3 size hoses, connected to the reservoir with an AN826-3D tee and a right-angle flare adapter. The adel clamps are intended to keep the left-side hose from trying to loosen the 90-degree adapter, and this part works pretty well.

My main concern here is that there may be too much unsupported weight on that little tee fitting. These hoses are not very long (they go straight down to the passenger's brakes) but still I worry. Am I okay here, or should I try to think of a way to anchor the upper end of these hoses to the structure?

My backup plan is to go back to using the nylon tubing for this stretch if I can't figure this out.

thanks,
mcb

 

[Brantel]

Make a Bracket

You have the clamps there already, just make a bracket to mount it to. I like your hoses better than what I have seen with the plastic stuff.

 

[dan]

Matt,

I would definitely support those, but if it's not too late you might consider using clear tubing per plans. The biggest reason imho (aside from weight, simplicity, cost) is that you can see the fluid. This comes into play when bleeding the brakes...when you use the "pump from the caliper" method (which I recommend).

 

[RV_7A]

Matt-

If you orient your lines on the T like I did, would work a bit better IMO.

-Jeff

 

[RV_7A]

I just realized these go to the passengers side pedals. You may want to use a steel T fitting there since you are coming straight back then.

-Jeff

 

[G-force]

How about not using any of that and using the master cylinder mounted res tanks Spruce sells? I think Dan C has those on his -7.

 

[dan]

How about not using any of that and using the master cylinder mounted res tanks Spruce sells? I think Dan C has those on his -7.

No, I used Van's stock brake fluid reservoir and the stock plastic fittings. I didn't install pax brakes, but that's about the only change I made to the un-pressurized stuff (reservoir to tubing to master cyls).

 

[Finley Atherton]

I have no experience with the plastic brake line and fittings supplied by Vans, but I do have 24 years experience with the plastic brake lines in my Vari-Eze and have never had a problem (can?t speak for other Vari-Eze owners). These are made from 3/16? Nylaflow tube (not Nylo-Seal) right down to the wheels and use brass Poly-Flo fittings (see ACS catalogue). The Aeroquip type lines are the ultimate answer, but if I have a problem with the Vans plastic lines from the reservoir, I will try the 3/16? Nylaflow tube with the Poly-Flo fittings first. It helps to use a short length of 1/8? OD copper tube in the 3/16? Nylaflow where it goes into the Poly-Flo fitting.
Fin
9A Australia

 

[Mel]

I've had the nylaflo tubing in my -6 from the reservior all the way through the master cylinders to the firewall for almost 14 years with no problems. It's cheap, light, flexes well and allows you to see any air that might be in the lines. (Pilot and passenger brakes). I don't recommend it down near the calipers because of heat.

 

[mburch]

Guys,

Thanks for the data points about the Nylaflo tubing. I wonder if my last RV just used a bad batch of it - the pitot/static system used it as well and it also developed cracks and leaks. After looking over this stuff again, I may see about using Nylaflo from the reservoir to the passenger side, but keeping the Aeroquip hoses from the passenger brakes to the pilot side and from the pilot's brakes to the parking brake valve. We'll see how that turns out.

thanks,
mcb

 

[robertahegy]

I've been flying for 2 1/2 years with the stock Van's plastic tubing with no problems. Save the weight and money for better things.

Roberta

 

[mburch]

Just thought I'd add some conclusion to my original question for the benefit of people searching the archives later. I ended up using the stock nylon tubing from the reservoir to the right-side pedals after all. Since I'd already done the work, I am keeping the Aeroquip hoses between the two sets of master cylinders. Even though it's overkill, it makes me feel good.

I also learned the lesson (yet again!) that deviating from the plans puts you in true Experimental territory - even on something as simple as replacing one kind of hose with another, you're sure to be in for a lot of head-scratching time!

Maybe I should rethink that PT6A FWF package I was planning to install...

cheers,
mcb