Just finished replacing front and rear rotors on my 96XJS 2+2.

The rears were absolutely a piece of cake.

Fronts were more of a chore (Mainly due to the shims placement) but I did manage to get it done.

Everything is working Great!

Now my question: On the fronts there are shims utilized on the Calipers.

1. What is the purpose of these shims?
2. What happens if they are left off?

Thanks

Softball Paul

1996 XJS 2+2 Conv.
1957 XK140 Drop Head
Every Other English Sports Car known to Mankind

 

1 = anti-squeal, they damp the vibrations that can occur between the pad and the disc that causes it
2 = nothing, except in my experience the brakes have more initial bite. orangeblossom has had problems when he fitted shims as they made the pads too tight a fit and jammed them against the rotors. Personally (takes cover) I never fit them.
Greg

 

Greg,

Thanks for the information. Kind of where my thoughts were.

I remember reading in the Kirby Palm book to make sure and replace after replacing Rotor.

Softball Paul

 

Are you talking about shims on the backside of the brake pads? If so, Greg explained.

Or are you talking about the shims to take up the gap between the steering arm and the caliper? If so, yes, reinstall the shims so the steering arm is not under strain and the toe-in setting stays correct

Or are you talking about the shims to centralize the caliper over the rotor? If you ever had them (unlikely), reinstall them only if you keep the existing calipers. If calipers are changed the need for the shims must be re-evaluated

Cheers
DD

 

On the Calipers only. It is the long and short bolts (verticle) to each other that have holes in the bolt head for wire to secure.

Thanks

Softball Paul

 

"On the Calipers only. It is the long and short bolts (verticle) to each other that have holes in the bolt head for wire to secure.

Thanks

Softball Paul "


If you mean the shim on the caliper fixing bolts, as in No 24 in this diagram:

Then you MUST measure the gap and shim it. The procedure is to attach the caliper top bolt and the steering arm top bolt and measure the gap between the arm and the caliper where the the bottom bolt will go through hole 15. Then get a shim to this same thickness and shove it in the gap and then insert the long bolt though the arm the shim the caliper and into the upright.
Greg

 

Sorry I wasn't more clear on my initial post, but you are correct!!

That is how I put it together.

Thanks