[szabgab]

Dear all,

I am in the process of renewing stuff around the front of my 400N Superdream, as the wheel omits this strange neither hissing, nor dragging sound, which I don't like much. I have already replaced the wheel bearings, as they were all wobbly, taken out the speedo dog, straightened it, taken the speedo gear apart as much, as I could and cleaned the junk from there too. the rotor is touching the pads slightly, so I have taken the brake apart (as far as I could go without completely dismantling it, basically splitting it to two), pumped out the master cylinder, sanded it with a 2000 grade paper and pushed it back, which was very hard to do without causing damage to parts. Also whilst there I noticed, that one of the axles, or shafts of the brake caliper (or what to call them) was binding, so I have removed that, cleaned it, re-greased, now it is moving in it's housing a bit freer, but upon reassembly the rotor touches the pads all the same. I have taken the bike for a test ride, and the strange noise, although is not so loud anymore, is still there. Now on the cmsnl site I have had a look at the diagrams of the wheels, and it looks like, there are some spacing shims underneath the rotors, which I definetely do not have on mine. Could this cause the constant dragging? If I put something there, washers, etc., would that foul the worn (but still very good) pads? If the spacers are necessary, does anybody know their thickness? Would it be enough to put two spacers underneath the brake caliper bolts, or is that a big risk of the damn thing dislodging and jamming the front wheel on the motorway?

Thanks!

Gabriel

 

[J-T]

Not certain they are the same but could you specify the part you are referring to in this fiche, or in a fiche specific to your bike?

OEM Honda Parts, New York | Honda Parts for ATVs, Scooters, Motorcycles. Located in Mamaroneck near Yonkers. Shop our online catalogs.

 

[filipe_azevedo]

I belive that the 1980 superdream has a diferent caliper, and the only shim that kind of caliper takes is a brake pad shim, something like the number 15 on the link provided by J-T.
https://www.cmsnl.com/honda-cb400n-superdream-1980-a-england_model15827/partslist/F09.html#results
In the superdream case is number 14. I don't believe that the spacers are necessary, I have a friend with that type of calipers and he doesn't have does shims mounted and he has no problems...
But, if you want they are still available from honda dealer, they could have something to do with brake pad noise... The most important ones are number 10 and 13. Make sure that number 10 is making enough tension on the pads...

 

[szabgab]

HI, thanks for the replies. I was not clear though, sorry for the confusion, the part I was referring to was no. 11 on this diagram - https://www.cmsnl.com/honda-cb400nd...gland_model17102/partslist/F10-3.html#results

 

[filipe_azevedo]

Thats a paper gasket, and the function is for damping the vibrations of the disk in relation to the wheel... You should mount one or you could make one from 0.5 mm gasket paper.

 

[szabgab]

Ahha, I thought, it might some sort of a gasket material. So if you tighten a 0,5mm gasket down what is the remaining thickness of it, around 0,1mm or so? That should not be enough to cause brake dragging, should it? I have read the procedure to correctly align the wheels by undoing the pinch bolts and the axle nut and doing them up again, one side at a time, whilst rocking the bike back and forth. I will give that a go too, but any other ideas, what could cause the pads touching?

Thanks!

 

[longdistancerider]

The paper shim will center the rotor to the caliper but that won't change the pad contact since this is a "floating" caliper, meaning that it moves and self centers to a degree. The slide pins and bores in the caliper have to be free of corrosion and dirt plus lightly lubricated to allow free movement. When you apply the brake the piston side pushes the pad against the rotor and then pulls the opposite pad into contact. Upon release the rotor movement will push the pads back very slightly, no visible clearance, until the wheel moves freely. They may still have some slight contact.
You might check the master cylinder bleed off hole in the base of the reservoir, that's the little tiny hole in what looks like a drilling mistake. When that hole plugs up it holds pressure in the brake system and keeps the brake slightly applied.