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yankee-flyer

Well Known Member
LOTS of questions today-- FAA inspection will be Monday and first flight-- I hope-- soon thereafter. This is a biggie. Three of the eight brake fittings on the master cylinders are seeping-- two or three drops a day. I've tightened them several times and am really worried about stripping those brass theads. At least 1-- and maybe 2-- appear to be leaking where the elbow screws into the master. Those are at the point where additional tightening-- if possible-- would require about 330 degrees turn to get them "clocked" correctly. At this point the only options I can see are to really honk down on the screw-on caps or to drain the brakes, unscrew the fittings and apply some kind of sealant to the threads. I did use, as recommended, EZ-Turn on the threads when originally fitting them. My flared connections appear to be OK-- it's those bloody ferrules on the plastic tubing that don't want to seal. If I drain the system, suggestions for thread sealant will be appreciated. Other suggestions that don't involve a couple of days work will be even more appreciated.


No leaks anyplace when standing on the brakes as hard as possible until I did the brake bedding, taxi tests, and brake test portions of the PAP, so obviously getting them hot has some affect.

THanks again, guys!

Wayne 120241
 
Wayne, I am facing the same deal, and plan on doing the repair when changing oil in 5 more hours. I inquired of Matco at Oshkosh and as told to get some white colored Locktite with a id no. of 173 or something like that. Couldn't find it anywhere at Kosh so while discussing with Lockwood folks they advised me to use the blue Loctite (medium hold strength). They explained that it will seal that small opening that exists between the threads of the mas. cyl. and the fittings. I originally used Hylomar fuel sealant, and that gave me what you describe. So it's off with the fittings and on again with the blue Loctite.
Dick Seiders
 
What I did

Wayne, I put locktite 'BLUE' on all those fittings. Have never had even dampness show on them. They can be taken apart if ever needed. Just a suggestion. Also, I did not tighten them super tight either. Just enough to be sure they wouldn't move if you bumped them.

John Bender
 
I had the same trouble with the EZ Turn sealant ended up using some liquid Teflon and no more leaks.
 
OK, thanks guys

Dick, I assume that you just lived with the seep during flight test and thereafter? Looks like the best way to drain the system is to pull the bleeder at the brake calipers and start all over again???
More fun, but at least it will fly!!

Wayne
 
tight fittings

I fought the same problem thru several fix attempts. The closure of the problem was to "fess up" to the tightness of the fitting, and use a teflon based compound. I used Locktite 567. Regarding the fitting instl; I basically tightened the fitting till it was reasonably tight, continue to the point that it is in the proper orientation, and then go one more turn. Also, don't turn the fitting CCW during this process, otherwise you have to start over.

Happy to say it's now leak free.
Hope that helps
 
I had leaks on my RV-8A brake cylinders and Bakerseal fixed the problem ... used Bakerseal on all my RV-12 metal fittings and no hint of a leak.
 
I had a couple of oil leaks at the pipe thread side of a couple of AN fittings. I had used the new version of Fuel Lube (EZ-Lube, I think).

At the suggestion of a couple of guys I met at the Holiday Inn at Hot Springs, SD last weekend, I removed and cleaned the fittings and reassembled them with Loctite 592 PST with Teflon. As suggested above, put the sealant on, tighten them, but do not go counterclockwise. Leave them set overnight before applying pressure or fluids.

Did the trick for my oil lines! Thanks guys from the Holiday Inn... I think they were from Texas. One guy was from the southwest part of Denver (Littleton?).
 
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