• Hi Guest!
    You can help ensure that British Car Forum (BCF) continues to provide a great place to engage in the British car hobby! If you find BCF a beneficial community, please consider supporting our efforts with a subscription.

    There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Subscribers don't see this gawd-aweful banner
Tips
Tips

TR2/3/3A Centering the brake rotors(disk)s in the front brake calipers using the shims?

karls59tr

Obi Wan
Country flag
Offline
How critical is getting the rotor to be dead center? Does it matter if one side of the rotor is a little closer to the caliper on one side? Someone said they tried the shims and it did not makes any difference? However I did read on this forum a suggestion to use "dental floss" to hold the shims in place when attaching the caliper hold down bolts, so I will do that if I do have to get the rotor completely dead center.
 
IMHO. As these types of brakes are referred to as self adjusting, close should be good enough.
Charley
 
As long as either side pistons are not bottomed out, I don't think you need to worry. I do check for runout using a dial indicator to make sure the rotor runs true. The side runout is what can introduce air into the system and also push fluid back into the MC, so you get a longer pedal travel on the initial push.
 
These calipers have two pistons, each of which retracts a scosh when you let off the pedal. You could have a pad 5/8 thick on one side of the rotor and 1/4 thick pad on the other side and it would work just fine. I have never understood the "dogbone" shims and leave them out. What can be a problem with new pads is that some of them are just too thick for the gap between the piston and rotor and drag even when hydraulic pressure is not applied.
Bob
 
My first choice would be a brake shop. You could try a belt sander or a wood planer. Planer would keep the lining and metal parallel, which is important.
Bob
 
Back
Top