Brake Locking up

[Larry]

Has anybody had the problem of one of the brakes on one side locking up with only a slight pressure on the pedal?
That happened to me and it appears that it was due to some grease that got on the lining and caused the shoe to self apply. When it applied it made the wheel lock up and even skid, something that you could never do with the foot pedal pressure. It released as soon as the pedal was released.
There was no warning that anything was wrong until one day this happened. My concern is that it might happen on landing and cause a violent swerve.
I cleaned the shoes and the problem disappeared now...but I don't know for how long.
Larry N4187

[Glenn]

Grease lock a brake? I can't imagine why grease would cause that. I can't imagine a Mite brake freezing. Failing, yes. Freezing, no. I do believe that Mal modified (lengthened) the brake arm to get a little better mechanical advantage. As I recall, your Mite has great brakes.

Are you still a member of SSA? I just let mine go after 37 years. There was a great article about 15-20 years ago about modifying Tost brakes so that both shoes become masters. It was really simple. SSA will e-mail you a copy of the article for a reasonable price. It would be nice to get permission to post it on the Mite site. The brake system is vertually identical and I see no reason why it wouldn't work on the Mite. Imagine being able to do a full static run up without moving forward. Kinda like imagining whirled peas.

glenn

And no it's not great to be back home. It's cold and wet up here.

g

[Glenn]

Larry:

Somewhere lost in my gray matter I seem to remember that Mal may have had the same brake problem. You may want to ask him. I'd like to think that my gray matter is better than his. Good luck. You can also ask his A&P on Orcas.

g

[Larry]

If it wasn't the grease on the shoes then I don't know what it was. Yes, Mal did have some longer lever arms on the brake but it has been operating for a long time with them and no problems were apparent. Yes the brakes were good for a Mite. But there was no way you could lock a wheel on the pavement by applying them. However, when this happened the brake would lock up and actually skid on the pavement with the slightest application. Then it would also release and roll along with no restriction. There is nothing wrong with the assembly inside that I can see. Everything looks normal.
They are operating normally now since I cleaned the grease off of the shoes.
Any other ideas??
No I am no longer an SSA Member but I have several friends who are so I could ask one of them to obtain the reprint of the article. Do you remember when it was that it was published?
Larry

[Scott Royall]

Hey Larry and everybody,
I drive a 94 Toyota 4runner. I just had some work done on the breaks and the rear end. It has disk brakes on the front and drum brakes on the back. A few days later it rained and when I applied the brakes, one of the rear wheels locked up on the slick pavement. I have also noticed it squealing on dry pavement. When I went to talk to my mechanic he told me that if you get grease or gear lube or other lubricating contaminants on the shoe it can lock up like you are describing. The fix is to clean off the contaminant from the shoe and drum or replace the shoe if it persists. I now have another appointment to drop off my car for another day in the shop to get it fixed. I haven't tried to replace or reline Mite shoes but I think the shoes are available. Have fun flying. I'm jealous; my plane is still in peaces.

[Larry]

Scott,
Thanks for the reply on the grease. I have now flown the thing a couple times since I cleaned the grease off with brake cleaner and a rag. Everything seems to be fine now but as you noted, it really locked up and skidded.
I am enjoying flying the Mite, I was without one for a couple years when I moved and had to sell the other one in Cleveland (N4180). So when N4187 came along I was able to get that one and have been enjoying it a lot since then.
Larry

[Joelj]

Hey Larry -
I have experienced the same condition on my Mite and it was after I had the wheels off. The left brake would catch and grip hard with very little pedal pressure applied. This happened on taxi right after the annual and on roll out after landing on the same flight, so I had to be careful. Then it cleared up and hasn't happened since - I assume it was the same situation, either grease or fingerprints or something that dirtied up the drum. Something for all of us to keep in mind, I guess.
Joel

[Larry]

Joel,
Thanks for the input. The problem has not resurfaced since I cleaned up the shoes. I did do one other thing at the same time however, I swapped the shoes top for bottom. There was some uneven wear on the lower one in the center of the shoe but the top one was showing almost no wear. So I flipped them. Things seem fine now.
Larry