A

Alan Erickson

Active Member
How much do the brake cylinder drip during typical zero- or negative-G maneuvers? Have you done anything about it? I have MC-5's on my 8A, and if you tell me that' I'll get messy brake fluid on my carpet and paint, I'll try to find a solution or build little check valves. Thanks for your help!
 
You need a RESERVOIR DOG!!! It's a little brass male/female fitting (1/8" NPT both) that seals the opening when negative and breathes when positive. Made by Alex Peterson.

20021105_reservoir_dog.jpg


I'm not financially offiliated with him. I bought one for my RV-7 and I've never, ever seen so much as a drop come out of the reservoir. That said, I don't do negative G stuff, so I'm probably not a reliable test subject...but I do think the design works.

I believe Alex participates in the VAF Forums and is probably watching...Alex you out there?
 
dan said:
You need a RESERVOIR DOG!!!
Click to expand...
Thanks, Dan! Of course, I just finished mounting up my MC-5 cylinders, so this won't work exactly - I'll hope that Alex has something similar for 10-24 threads...or switch brake cyls back to something Van-like.

Still would like to hear about upside-down folks' experiences! - though it does appear that this will be of concern to me, since Alex saw fit to make the above part.
 
When I used to do more negative stuff in my -6 I originally had some fluid puke out of the reservoir, but I too ended up with one of Alex's little widgets and now haven't seen a drop....but I don't do too much negative stuff anymore either. I have full inverted fuel/oil on my plane, but upside down just isn't much fun in the -6 for any extended time (seatbelt and seat geometry just suck in these planes and I tired of banging my head against the canopy)....

Cheers,
Stein

RV6's, Minneapolis
 
Dan, I am out there! See:

http://www.home.earthlink.net/~reservoir_dog/

for details.

Alan, I do not have a solution for 10-32 threads. I scanned the McMaster catalog and did not find a bushing. It likely exists, but I'm not sure where to find one. How do 10-32 straight threads seal, with an O-ring? I know of some fittings called "instant tube" which use 10-32, but I do not know the mechanism of sealing.
 
Alex, the MC-5's have a 10-24 straight-thread vent cap -- a nylon socket cap screw with a small hole drilled through the shaflt -- and no special sealing mechanism (though one could certainly add a noncaptive o-ring).

I think I'll just solve the problem more easily: this morning, I converted back to the standard Van's cylinders, and will just order two reservoirs from Spruce and two 'dogs from you. After she's up in the air, somebody'll get a good deal on the MC-5's.

Thanks, everyone!
 
The F1 that I built does a lot of negative "G" and no fluid spills. I used a PVC valve threaded into the top of the brake resevor it allows the tank to breath while right side up and the valve closes while inverted.
 
You must log in or register to reply here.