79 xs400 2f front drum break shakes like crazy

[dizzle]

hey all im hoping you guys can help me out here i have on my xs400 i resently changed my front breaks shoes becaue it was shaking like a mad man under heavier breaking not so bad under light breaking.
i changed the break shoes to new ones and it still seems to shake but not nearly as bad could it be an adjustment issue with the shoes when they contact the drum? i tryed to line up the cams as best as i could when i had the plate off , is there a different way to set them up? or is it possible that my hub is warped i dont kno if it is a comon thing or not. i called my local yamaha store and they said that the hub is discontinued and i would have to get it off of ebay. my other option was to try and rig it up to a break lath and try and lath the drum surface, but im not to sure about the tollerences and the runout etc.
any opinions?

my last thought is it is what it is and just keep on riding

 

[HoughMade]

My first thought, which is easiest to correct, is that oil or some other substance could have gotten on the inner drum surface and even if you can't see it, it can cause uneven friction as you brake. Clean the drum with brake cleaner, followed by a thorough rough up of the surface with 80 or 100 grit sandpaper, the clean it again and see what it's like- certainly can't hurt.

 

[xschris]

There is a dot on each of the cams for the drums they must be at the same point. Unless you can get the drums turned to true them you will get some pulsing with hard breaking. I have a 2-f with 30k on it and with new pads it will do it a little but only under very hard breaking. Its just how they are They are not race bikes or meant for heavy riders.

 

[dizzle]

@ houghmade good point i will have to do that again i did spray break clean all over wiped it down and scuffed with some 150 grit but i will give it another go and make sure it is spotless

@ xschris what do you meen its not a race bike hahah and i am not be any meens a heavy rider like 5'10 165 pounds and as for the turning the drum i think i will try and get it on a break lath and at least see how bad it is if any mabey i could take a skiff of to true it up. and the dots on the cams look pretty damn close to me .

 

[xschris]

I am also 165 and 5'10 If the cams are off the brakes will feel squishy.

 

[dizzle]

Thanks for the advise in gonna mess around with it today and see if I can get it any better