Could use some help before I visit repair shop re a nail in a tire

[ML Auto]

The arrow should point in the direction of rotation. Up is correct. That forces the pads up to remove play when applying the brakes while traveling forward.

 

[Mark77a]

Yes, pads are biased UP wards (in direction of rotation) to stop rattling.... more pix below.
I hope this explains.

as fitted....

Note the hard rubbery patches below the pads (I guess a previous Tesla / lotus attempt to stop rattling).


Also FWIW, the back of the pads had a small amount of thick grey brake grease, which will also help - a bit.
These are CarboTech pads, which have (black) metal plates transferred from original Tesla pads. These backing plates just seem to take up width, and provide a flat smooth surface for the pistons to act on (vs more irregular back plate), they dont contribute to anti rattle. LH below, as grease spread, RHS after trial fitting.

Key point: avoid much hard braking in reverse, as this can undo the upwards bias and the dreaded rattle will return.

 

[dpeilow]

I've started noticing a little rattle from the right hand front now. I have a suspicion there is a temperature component to this, as yesterday was pretty hot here. It would make sense if the clip in Mark's pictures expands and there is a bit more play with the two pins.

 

[thefortunes]

Just fixed annoying brake rattle.
Turns out it can be fixed by ... wait for it ..... the anti-rattle spring plate
View attachment 191264
See the little hook along the top of this plate - which hooks onto the top pin - call it a
Also see the horizontal wider bit below the hook - call it b

b fits under the extension of the backing plates, around top pin hole, that sticks out backwards.
The pin holes in back plate are much bigger than the pins so the pad can move, expand and be pushed UP against caliper on braking.
When the spring is new (or tweaked), b holds the pads higher, nearer to the top surface inside the caliper which they are pressed against on braking. This also means they dont rattle - which is the pads especially when hot / expanded bouncing on the lower surface of the caliper.

The cure is: buy new anti-rattle spring plates AND/OR make sure they hold the pads HIGH in the caliper (braking position).
I found my 26K old anti-rattle spring plates allowed ~1mm free play which let the pads bounce about enough to hit the lower surface of the caliper. The free play downwards, can be reduced by reducing the distance between a & b.
I found the easiest way to do this was the very slightly squeeze the hook, reducing its inner radii, and so reducing the a to b gap.
This simply raised the pads by about 0.5mm, without adding any more friction or restriction in movement.
The pin holes in brake back plates are now held so that pins sit below centre - as pads sit higher.
View attachment 191267
After getting annoyed by this rattle coming and going, and loads of surprising miss-info 'bum-steers', on various forums etc. this worked.

What bends the anti-rattle plates, so they need renewal/tweaking, and make the rattle worse, is braking in reverse, especially when pads are cold, or slightly smaller higher performance pads (which might be smaller for wider expansion tolerances), this pulls the pads DOWN, stretching the anti-rattle plate in the wrong direction, hence allowing the pads rattle on the bottom surface.

Please note: all "you do at own risk" provisos apply to these notes.

I put Carbotechs on about a month ago (without the goo) and noted the rattling. Hadn't done anything about it yet.

Saturday I had the front tires off (long story, but apparently tire shops in the town to which I moved do NOT have low profile jacks so I had to pull the wheels/tires off myself and take them with the new tires to be mounted and balanced).

Took all of 2-3 minutes per side to pull the anti-rattle spring plate and slightly bend the hook.

Between the rattle being gone, quieter tires and wrapping the fix-a-flat (which was "bouncing" in the bottom of the trunk on every bump) in a microfiber towel my commute was NOTICEABLY quieter this morning.

Thanks Mark!

 

[gregd]

Between the rattle being gone, quieter tires and wrapping the fix-a-flat (which was "bouncing" in the bottom of the trunk on every bump) in a microfiber towel my commute was NOTICEABLY quieter this morning.

What tires did you go with that gave you the quieter ride?

 

[thefortunes]

Sorry for any confusion.

They are the AD07s, but are quieter due to the fact they actually have some tread compared to the set that was replaced.