Brake shutoff valve

[Greg Arehart]

I'm in the process of putting extended axles on my 9 so that I can use 6-inch wheels when necessary. I'm thinking of putting a shutoff valve on the bottom of the brake line (at the wheel) so that I can avoid having to bleed the brakes extensively whenever I change wheels.

Has anyone ever done this? Suggestions on a valve that is light and small enough to put there? Reasons not to do this, assuming I can find a valve that fits inside the wheel pants/fairings (other than weight)?

Thanks for any input.

cheers,
greg

[Tom Martin]

I had tried a different kind of "curl" on my brake line on this plane and that idea caused about three failures at the fitting. I have since gone back to a standard larger loop with no problems. However what I did discover, during those repairs, was that if you remove the breather vent from the master reservoir and replace it with a plug you can work on the bottom of the brake lines without having to bleed the system. This has to be done before you open any fittings and there must be fluid left in the master reservoir for this trick to work. After the repair, or wheel change in your case, just put the vent back in place and give it a try!

[rocketbob]

Why not just use 380x15x5 tires, which are a 6" tire on a 5" rim?

[Mike S]

Originally Posted by Greg Arehart

I'm in the process of putting extended axles on my 9 so that I can use 6-inch wheels when necessary. I'm thinking of putting a shutoff valve on the bottom of the brake line (at the wheel) so that I can avoid having to bleed the brakes extensively whenever I change wheels.

cheers,
greg

Are you also changing the brake calipers???

If you are not changing the calipers, only removing them to facilitate the wheel change, then use a piece of hose to allow the caliper to swing out of the way, without having to disconnect it.

[N941WR]

Greg,

You don't need it. During my engine replacement, I never once opened up the brake lines. They just unbolt and you can move them around as needed. That is with the SS lines we exchanged emails about.

[Greg Arehart]

Good suggestions all. I will be using flexible lines, and the brake reservoir trick sounds perfect. Mike, I don't know whether I will need to change brake calipers yet until I buy some wheels. Would be ideal if I don't need to even break the line! Bob, I just wanted some more tire options for flying into some rough strips in northern BC/Yukon. Might not need huge tires, but I'll see this summer.

Thanks,
greg

[scsmith]

Originally Posted by rocketbob

Why not just use 380x15x5 tires, which are a 6" tire on a 5" rim?

The 380 x 15 x 5 (also 15/600 x 5) tires are GREAT! fits stock axle, hub, brake, wheel pants, but gives almost all the benefit of a 600 x 6.

I did mount my wheel pants 1/2" higher than stock to get extra ground clearance as well.

I strongly recommend a flex hose at the brake connection rather than a hard tubing loop. Sounds like Greg's doing that.

[Greg Arehart]

Yes, I'm a firm believer in the flexible brake line rather than the aluminum tube. Last thing I need is brake failure (well, I guess engine failure was not fun either).

So, I'm trying to figure out tires - the designations are all a mystery to me - any links or suggestions on where to find the specs on these? I've found a few things that are close on the Desser site, but none really tell me that they will fit on 5" rims etc. And how much fiddling does it take to fit them inside the standard wheel pants? Here's the tires I think you are describing:

http://www.desser.com/store/products...RAFT-TIRE.html

Certainly would be cheaper than a second set of wheels....

greg

[LarryT]

By depressing the master cylinder slightly, the seal will travel past the compensating port (hole where fluid enters m/c from reservoir). Then the far end can be opened without losing fluid (similar to pulling a soda straw out of a glass with your finger over the top of the straw).

This is only for FYI. Personally I would use braided SS teflon hose because aircraft brakes are more of a PITA to bleed than cars. The flex hoses on my cars enable me to change disc brake pads without opening the hydraulic system at all. Just push the pistons back into the calipers with a big C-clamp.

LarryT

[WingsOnWheels]

You can buy quick-disconnect fittings that are used on motorcycles for racing. They are designed for this purpose and I have never seen a failure. Motogp brakes see far worse conditions than the RV any day, if they can handle that abuse they should do just fine.

http://spieglerusa.com/brakes/quick-disconnect.html