Rubber sleeve on caliper pin.... Why?

[ZZman]

Why are those rubber sleeves on one caliper pin and not both? Are they even really needed for operation?

 

[Jimmy_Russells]

The boots? They should be on both, they keep water and dirt out so it can slide nicely. Same thing as a shock boot.

 

[doitmyself]

They are there to confound us that use rubber swelling lubes and/or live in the rust belt.

Here's a simple answer: https://www.google.com/url?sa=t&rct...actually-do/&usg=AOvVaw3nVfDwrNkhBS2SxBmGoTW_

Seems they are there to help noise abatement.

 

[930.engineering]

NVH

I have replaced these plastic (it isn't real rubber) bushings with bronze bushings in the past for improved pedal feel. However these may be noisy depending on pad compound, moisture and temperature. Bronze bushings require frequent regreasing which plastic sleeves don't.

 

[Jetronic]

you can also go with 2 pins without bushings if you like, but the caliper can rattle a bit on some cars.

 

[ZZman]

The boots? They should be on both, they keep water and dirt out so it can slide nicely. Same thing as a shock boot.

Not the boots. These are at the tip of one caliper pin.

 

[ZZman]

They are there to confound us that use rubber swelling lubes and/or live in the rust belt.

Here's a simple answer: https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&cad=rja&uact=8&ved=2ahUKEwj0oLiVvvTwAhUZVs0KHfE4Bc4QFjAAegQIBBAD&url=https://blog.1aauto.com/what-does-the-sleeve-on-the-lower-brake-caliper-bolt-actually-do/&usg=AOvVaw3nVfDwrNkhBS2SxBmGoTW_

Seems they are there to help noise abatement.

Funny that caliper pin was stuck in the hole because of that. Took a while to get it out. That side appeared to not be working well.

 

[ZZman]

Worked on the fronts today and had another of those odd slide pins froze up in the bracket. Took some heat and PB blaster to get it out.

 

[Hall]

Why are those rubber sleeves on one caliper pin and not both? Are they even really needed for operation?

They are supposed to dampen vibrations among other things and are typically only on the leading edge pin. While there doesn't seem to be a definitive answer, you can be 100% certain that the automakers wouldn't end up with (2) different pins per caliper (the other is usually fluted, by the way) along with the add'l piece of rubber if there wasn't a real good reason.

When I'm getting ready to do brakes, I find out which pin it's supposed to be on (if it uses them) to make sure it's in the right position. Putting it back "where you took it out of" isn't always right, in fact, you're only assured of being 50% right.

 

[SoNic67]

I didn't found that contraption on Ford, Kia, Hyundai brakes.
I guess I'll see soon if Toyota has it...