Idk if it has been covered or not or if it is even routine maintainance but anyway when i did the rear brake mod i still had a bit of sticking on the brakes.

So what i did was lube the shaft with some cheapo chain lube. The brakes work very smoothly and i have no complaints even after 2 1/2 weeks of riding everyday.Just make sure to clean all excess lube so it doesnt get on the housing or brake shoes.

Also go back and check later to make sure no lube seeped out of the shaft housing. I havn't had a problem with it but cant hurt to be sure.

I dont see why it would matter what kind of lube you use , just make ssure it's something long lasting and semi solid . I doubt wd-40 would last long enough to be worth it. And i would be worried there is more of a chance that some of it would get all over the place and on the shoes having a lower viscosity.

Give it a shot and post up here so i can see if others had good luck with it.