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SuperCub MD
05-23-2002, 01:41 PM
Thought I'd start something new. A lot of good little tips are getting scattered elsewhere, here's a place to bring them all together. Most of us that deal with Cubs have probably come up with all kinds of little tips and tricks for maintenance, repairs, use, and such. Not big mods, just little things that make the Cub better. If you have come up with something that works, or a better way to do something, let's here it.

pak
05-23-2002, 04:56 PM
Annual disassembly of the cleveland calipers. Removal and cleaning of the pucks and replacing with new O rings. Cleaning of the torque plates/ brake pins and channels. This keeps everything working smoothly, prevents excessive heat build up and unexpected seizure of the brakes.pak

Rick Sanson
05-23-2002, 05:57 PM
Any tips on the master cylinders????

Both my brakes leak fluid, over a period of time, though I don't see where they are leaking...

Thanks

SuperCub MD
05-23-2002, 08:57 PM
Rick, New diaphrams cost about 7-8 bucks, easy to replace. Also put a new seal on the cap, and make sure the return spring is still strong while it's apart. Nothing to it.

Crash
05-23-2002, 09:07 PM
If you clean everything up around your master cylinders you can usually see where the fluid is escaping. Make sure everything is tight and the seals are in good shape. Some times it is leaking from the parking brake valve. If you are running booster brakes, a little fluid loss will cause a lot of brake loss. One weak area on the brake system is the Cleveland 6040 caliper will crack very easily where the bleeder and pressure line fittings screw into the caliper. These are tapered pipe thread fittings so the more you screw them in, the more expansion pressure they exert on the casting threads. The crack is a hair line one on the face of the caliper and you need to wire brush the paint off to see it. If you have access to a TIG welder you can V groove the crack and weld it shut, then re tap the threads. Never over tighten these fittings. Put some Permatex sealent on the threads and just snug them down. Crash

SuperCub MD
05-23-2002, 09:16 PM
Something else on brakes, soft petal feel. A lot of it can be weak, broken floor boards flexing. The front floorboard always breaks between the rudder petal and brake petal holes due to flexing when the brake petal is depressed. The easy fix is to make a steel tab that lays on top of the board under the inboard rear rudder petal mount bolt, and the inboard front brake petal mount bolt. (Just like the other floorboard tabs, only shorter and thicker, about 1/16" thick works good) This then gives the brake petal support from the rudder petal welded on mount, instead of just hanging on the plywood. The brake petals feel a lot firmer, and the floorboard never breaks. If your board breaks here, just install the tab over the break, instead of replacing the board, which is a big job.

SuperCub MD
05-23-2002, 09:36 PM
Something else on brakes. I like to replace all the hoses and lines with one stainless braided, teflon hose from caliper to parking brake valve. This eliminates a lot of leak soarces, and I don't have to worry about someone stepping on the copper line when getting in and bending/breaking it. I just put one AN fitting on each end, measure the length I need, and order it from the hose shop. If you add up the cost of all the parts in the stock system, this is LOTS cheaper, and works better.

Crash
05-24-2002, 01:05 AM
I like to weld on a fuselage tab just behind the front gear fitting to the inside of the longeron and install a 45 degree bulkhead fitting. The phoney little fabric ring that glues to the fabric with the aluminum cover (where the hose exits the fuselage) always breaks loose over time. This leaves the hose a floppin. You can use a short stainless tube or hose to connect the master cylinder to the bulkhead fitting, then run a hose from the other side of the fitting straight down the gear leg to the brake caliper. For 30 bucks you can buy the mandrel and make your own hoses. I put one end on, then mount it to the airplane and mark the hose where it needs to be cut holding it next to the fitting on the other end. Nothing is worse then a too long or too short brake line hose. Crash

PA12driver
05-24-2002, 01:17 AM
To each his own, but I like to mount the calipers to the front and then the hose is in the rear, somewhat protected? Also I (always) carry a little squeeze bottle (good source is REI) with the red stuff to top off the booster brakes (If they get soft and they do just from wear) you can (end up getting the rudder before the brake or visa versa, and then the dancing begins!

Another thing that I often see is people don't properly break in "new linings and or new disks) Critical is to heat them up and cool them off a couple of times so they don't glaze over!!

Another no no (should be common sense) is when a shop bleeds your brakes for you! Don't just take off and go land on a one way short strip thinking the brakes will be like they used to be) Alot of bent airplanes happen that way!

Tim

SuperCub MD
05-24-2002, 08:08 AM
Thanks Tim, I forgot about the caliper mounting. I also put them on the front, but upside down from the useual installation. Bleeder on the bottom, hose out the top and tucked right between the gear legs. All that stock plumbing hanging below the leg is just waiting for the right stick to catch it.

And on the hoses, I have the shop make them because the outside diameter on them is small enough to fit into the stock gear leg clips, home mades are to big, and have to be taped on, or have bigger clips welded on the leg. Also, I get them made for about 20 bucks, tough to buy the ends and hose for homemades cheaper.

Rick Sanson
05-24-2002, 08:17 AM
"Hold" on here guys! Gimme a "brake". "Stop" me if I'm out of control here. I'm a bit "slow" but this thing needs to come to a "screeching halt".

Sorry! I couldn't "resist"!

This is very good info! Thanks!

SuperCub MD
05-24-2002, 09:52 PM
Staying in the main gear theme, a tip on lower shock struts. Anytime you have them off, (like bungee changes), check them for internal moisture and corrosion. I have dumped a lot of H2O out of these when removed. Before reinstalling, check them for corrosion, if OK, slosh them with tube seal, and apply RTV in the top end before reinstalling the hydrosorb fitting. This should keep out future moisture. At inspection time, always check the lower strut area next to the gusset for pin holes, blisters, or other signs of internal corrosion. If suspicious, punch with Maul tester, or pick. The old style, nonhydrosorb gear are even worse for collecting moisture. Always put lots of grease where the upper and lower slide together to prevent moisture from getting in.

SJ
05-25-2002, 06:37 AM
Cub Experts: I just added a Tips and Tricks forum specifically for this splendid idea of yours. That way you can make topical (i.e. BRAKES) entries in it and we can track things down later!

Thanks for all the good info on this great thread!

sj

cubdrvr
05-25-2002, 08:42 AM
Years back ( when I was flying more with cowboy boots) I would cut and trim a piece of sticky-back wingwalk tape to the brake pedal fronts. This would still allow for a good grip if you didn't catch the pedal with your entire heel. Still do that today out of habit. You'll appreciate this one if you ever had your heel slip off the brake in a gusty crosswind situation.

PA12driver
05-25-2002, 12:26 PM
MD,

Yeh, I do the same (only I never thought mine were upside down) Seem alittle stupid to put the brake line hanging at the lowest point??

I was told that you couldn't get the air out bleeding the brakes with the bleeder pointing down?

The proceedure I use if starting from scratch with a clean system is to use an box-end ignition wrench caught between my pump can of the red stuff (with a vacumn line hose on the end attached to the bleeder.

I open the resevoir (top of the brake booster) wrap a rag around it!
If I have help I have the guy (slowwwwwwwly) pump the brake fluid into the system until the fluid comes out th top with (no air) then while I slowly still pumping I tighten off the bleeder, top off from above the resevour and we are done.

AFTER BURNING IN THE LININGS--- I top off again from the top! (a couple of drops every week or so if needed. (bottle of stop juice) is always in the seat bottom storage along with a 5/8 or a cresent wrench.

Steve's Idea to move this discussion area to "Tips and Tricks" is a good Idea! see you all there.

Tim

Fabman
08-15-2002, 02:46 AM
One more tip for brakes

I have seen several of the original style parking brakes (the cast type) crack at the lower fitting, if your brakes are always needing to be pumped up and you have tried everything else you might find the problem there. The crack is sometimes very hard to see. I remove them to inspect them properly.