Brake res. plug

[Mr. Ed]

I'm in my first annual since purchase. Checking the brake res. for fluid level I found that the res. plugs were light plastic orange plugs of the type that you would find as shipping stoppers in ports or tubing. They looked like they had been chewed on by a dog and stuffed back in the hole. The parking brake locking plate is in the way of direct access to the filler hole, so a screw in plug with a head will not work, besides not being vented. The current plugs are vented by way of a bottom corner of the plug being snipped off.

My question is: Is this the way Maule designed it or has it been modified? If it is by design, where might I find some replacements for my munched up plugs?

Been having trouble with Maule parts people lately so I hesitate to ask them to send me anything. I ordered some parts and got a shipping quote from them. They cut up a huge box and turned it into a very large box which they tossed my parts into. My parts occupied about 25% of the box. They then charged me 3 times the quoted shipping price to send this ginormous, mostly empty box. They also forgot to send two items in that order. Next order they sent was entirely the wrong part plus another parts bag was missing some components. What's up back there?

[xwildcat]

FWIW regarding Maule's parts dept... I ordered some new oleos and a stress (bolt) kit. They were packed tight in the box surrounded by foam rubber and arrived quickly after being shipped the same day. I dealt with Barry. He was great by both phone and email.

[UP-M5]

my brake master cylinder plugs were junk too- here's what i did:

bought 2 new brass pipe thread plugs from local hardware store.

drilled vent holes with very tiny drill bit. vents are upside down "L" shaped, instead of being a straight hole drilled all the way thru. (does that make sense?)

they go in finger tight only. have worked perfectly for several years now.

[Mr. Ed]

Yeah, it makes sense but it also looks like my parking brake hardware would get in the way of the square head on the plug. I did pick up some hex head plugs and if I decide to use them would drill a vent hold but haven't decided what to do about it yet.

Any suggestions Jeremy?

[210TC]

You will need to adjust a little bit when you conduct biz in the south, just like one would have to do in the opposite direction.
This has happened to just about all of us and one thing you will learn is no matter how much you try things are not going to change.
You can give these folks a little credit, they have not gone belly-up and they provide a very inexpensive airplane.

[a64pilot]

Ed,
Did you call them on the screw up and give them a chance to "make it right"?

[Mr. Ed]

Yes, I called and left a message. They called back and agreed they did screw up the order. They gave me an authorization number to send the part back (at my expense) and said they would send the correct one out and not charge for shipping since it was their mistake. Well, the new part arrived today aaannnndddd they tacked on shipping and handling charges!

BTW I shoved the dog chewed plugs back into the reservours till I find something that will work. I bought hex drive plugs but there's nothing to keep them from falling into the reservour if they get "over screwed" or vibrate in another turn. Maybe I could just pean over the top of the plug a bit so it wouldn't thread down that far. You all know that you gota have circus type flexability to get to those little widgets. I don't bend well anymore, probably never have, so it's a pain in the neck doing battle with something like this that most likely cost fifty cents.........if you could find them.

[MauleMedic]

They looked like they had been chewed on by a dog and stuffed back in the hole.

Yes, these are more typical than most mechanics like to think about. They are found not only on Maules but other aircraft as well that use the Cleveland (style) integrated master cylinder / reservoir.

These typically come with a little (0.125 x 0.125 in) plastic tab that sticks up which rarely stays attached past the first removal. (Especially if people try to pull the cap out without first loosening / removing the p. brake lock arm.)

I'd be careful about replacing it with something that might fall down into where the action is...you'd hate to have one brake get locked down...at the worst moment. But I'm trying to remember if it's a NPT (pipe thread) which I think it is and as such the threads get narrower the farther you go into the hole. I'd just try it and make sure they won't ever have a chance of ending up inside the cylinder.

I know of a lot of Cessna's that replace these thin plastic caps with full plastic caps (i.e. similar to what was described above with the r shape vent hole but made entirely from plastic).

Alternatively you can just get a bag of the original style caps and figure on replacing them every time you pull them out.

You're on the right track though - just be careful that your new caps won't interfere with the p. brake.

[TomD]

Locktite has a whole series of bonding liquids/gels that can either be permanent ( like REALLY permanent) or will break free with a wrench, but I don't know how they would work in an oily environment. If the hole and plug were clean, then you could use a drop of "breakable" Locktite and the plug will stay put.

I am a big fan of fingernail polish on threads ( color to meet your personal preferences ) to keep things from vibrating loose. Easy to break loose and Acetone will dissolve it readily.

TD

[DonMc]

No need to take plugs out of reservoir. If fluid is low you will feel a low or soft pedal. Just wrap the cylinder with a pig blanket and pump fluid in from the caliper until the fluid appears on the pig blanket. Now you are full and bled and life is grand!

Don

[DonMc]

No need to take plugs out of reservoir. If fluid is low you will feel a low or soft pedal. Just wrap the cylinder with a pig blanket and pump fluid in from the caliper until the fluid appears on the pig blanket. Now you are full and bled and life is grand!

Don

[Mr. Ed]

I kind of liked the contortions I had to go through to get under the pannel to fill them from inside. Now I can add that to my resume and get a job at the circus.

The Maule maintenance manual says that they should be filled to 1/4" from the top. I would assume that if you filled them to overflow from the bleed at the caliper you would eventually have red insulation and then staining on your belly fabric. Even using a pig blanket while filling.

As far as the threads tapering, they may indeed. However, the threaded hole is only about 3/32" thick. I doubt if there is enough taper in that distance to make a difference. Think I'll go with the suggestion of buying a bag of the little ditties. Now, anyone got a bag of them for sale?