Brake pad shims

I'm about to rebuild the front braks on my '83 Seca900. I bought parts from Chacal, including shims that are supposed to be located between the caliper piston and pad. I write "supposed" because thay are not shown in my manual and there weren't any in my calipers.

Where I am puzzled and Len couldn't give me an answer is as for the number of shims for each caliper. Mine are dual piston calipers, and Len sent me only two shims. He's the one who proposed I post the question here.

So, my question is: do I need two shims per caliper (one per piston) or only one shim per caliper? In the last case, do I put the shim on the wheel sode or the opposite?

In the first case, what else except new shims could I put there, because they are expensive and I wouldn't like to buy two more.

 

Good question. I've only seen those shims used on the single-piston Yamaha calipers; the USA-market 900s had single sided calipers too, according to the fiche. But I don't see any pad shims in the USA XJ900RK fiche, even though it has single piston calipers.

In their application in the single-piston caliper, they go on the piston-side pad.

We need input from a Euro or Canadian market 900 Seca owner that's seen the original brakes.

 

I use Ferodo Pads on my 900.
I've never used a Shim or Disc Brake Quieting adhesive.

 

I bought EBC organic pads from Len, they are the less expensive ones he sells.

But I doubt the pad model has something to do with shims. Pads should be all the same thickness.

I understand that you should put the shim between the pad and the piston.

I've already heard of some XS650 owners using a part of an aluminium beer can as a brake shim. I will probably ask these fellows too.

 

I looked into quieting some brake squeal on my friend's ZZR1200,
and the application of shims, or goop, was to the piston side.
.
Seems that the piston's "loose" fit allows the vibration, as the other side is "fixed" to the rigidly mounted caliper.
.
Loose and fixed are relative.

 

With dual piston set-up, there is no "rigid" side, both sides are "loose", well, this is my understanding.

 

Hey - you're right, but my research was coming up advise for cars.
I'm sure the ZZR had multi-pistons in every direction.

 

Soooo, conclusion is I'd need 4 shims for my Seca900, since I have four pistons?

 

4 shims - that would make sense,
The ZZR guy was cleaning his front rim and got some "orange cleaner" overspray on the discs, then cleaned that off, and the squeal went away (just in the last few days).

 

Got answers from some XS650 guys who actually used beer can pieces as pad shims. I'll have to figure if I'll be using one piece of beer can and one "real" shim per caliper, or if I'll go with one all-beer-can caliper and the other one all-real-shim, or if I send real shims back to Len after I make four beer can shims...decisions, decisions..!

 

Oh fer chrissakes. Don't use beer cans, they'll get pounded into dust in a few thousand miles. Buncha bloody amateurs.

Go find a real auto parts store; not a big-box chain but an old-school auto parts with wooden floors. Maybe a Canadian Tire, but I kinda doubt it.

What you want is called "shim stock." Back in the old days, it came in a whole lot of different thicknesses and both brass and stainless. Nowadays, take what you can get. It'll still be better than beer can stock.

 

bigfitz

I'm pretty sure I have a metal sheet of the right thickness in my shed, I should have talked about it instead of "beer can stock". Actually, I don't have any, I drink only bottled beer.

If I don't happen to have a metal sheet, I'll follow your advice and try to source "shim stock". Good thing I got you a bit impatient, I completely forgot about auto parts shim stock, lol!

 

I looked at the Factory Manual and the Yamaha Parts Site.

Although "Shim" is mentioned, ... the Manuals Exploded View and the Sites Diagram and Part List does not show them.

 

It looks like Yamaha guys simply forgot about showing the shims.

I actually have a metal sheet scrap piece that is a bit thinner than the real shims but a lot thicker than beer can stock. I will use it.

Can anyone explain why real shims are not exactly the same shape as the pads them selves? THey are cut at a weird angle:

http://tinyurl.com/qcqggg8

 

If this is for stopping rattle of the pads, loctite high temp red silicon worked for me, put a little on the ring of the piston where it pushes on the pad. Work the brake so it settles evenly and let set. It's good exhaust sealer too.