Caliper slide pin

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Does anyone know the purpose of the rubber bushing on the caliper slide pins? It is usually located on the top slide pin only for some reason. Also what happens if we remove the rubber bushing, any benefits or side effects?

Thanks
 
Noise, vibration, does nothing, no one knows, .... There's varying opinions on them. This gets asked a fair amount....

I'm of the opinion that the brake engineers had a reason to design these into the part. Just because no one is 100% sure what that reason is doesn't mean they're not needed either.
 
Why would you even consider removing an item designed to keep the grease in and nasty items out?
 
Originally Posted by painfx
Does anyone know the purpose of the rubber bushing on the caliper slide pins? It is usually located on the top slide pin only for some reason. Also what happens if we remove the rubber bushing, any benefits or side effects?

Thanks

on VW's it's how they call it a semi-floating caliper design, which uses rubber on both guide pins guides.

Removing it and replacing it with a harder material.. less flex, and interestingly enough wears out the pads quicker and more evenly.

http://www.tyrolsport.com/braking/tyrolsport-brake-caliper-stiffening-kit-for-vw/audi/
 
To reduce caliper rattling and slapping in floating caliper designs. There is no effect removing the bushings maybe lesser drag. My 02 Silverado had them in both lower and upper pins in the front calipers. When I used the wrong grease they swelled up so I removed them. Later caliper designs got rid of the bushing and opt for a tighter pin fit in the caliper bracket.
 
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It's usually on the leading pin, and slows the application so the trailing edge of the pad touches first, stopping squeal and evening pad wear.
 
Takes up the small space between machined hole and pin to stabilize caliper. Replace with OEM part only. And don't use any of the Permatex brake goops. They swell the bushing. Know from experience. NO goops.
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Originally Posted by user52165
Why would you even consider removing an item designed to keep the grease in and nasty items out?

You're referring to the rubber boot. That's not what the OP is asking about.
 
Originally Posted by hallstevenson
Noise, vibration, does nothing, no one knows, .... There's varying opinions on them. This gets asked a fair amount....

I'm of the opinion that the brake engineers had a reason to design these into the part. Just because no one is 100% sure what that reason is doesn't mean they're not needed either.


Right, I am here to find out the reason why.

Originally Posted by user52165
Why would you even consider removing an item designed to keep the grease in and nasty items out?


Why only the top pin has it and not the bottom?

Originally Posted by Kibitoshin
To reduce caliper rattling and slapping in floating caliper designs. There is no effect removing the bushings maybe lesser drag. My 02 Silverado had them in both lower and upper pins in the front calipers. When I used the wrong grease they swelled up so I removed them. Later caliper designs got rid of the bushing and opt for a tighter pin fit in the caliper bracket.


This is what had happened to my friend's ES330. His top pin bushing where seized. Removed the pin out and they were swollen. Then he removed it, no more seize and the braking force is better than before. So he was wondering if he can just drive without the rubber bushing on the pin.

Originally Posted by Silk
It's usually on the leading pin, and slows the application so the trailing edge of the pad touches first, stopping squeal and evening pad wear.


Is that your final answer?
 
Why is there only 1 rubber bushing on the top slide pins and not on the bottom?
 
Originally Posted by painfx
Why is there only 1 rubber bushing on the top slide pins and not on the bottom?


I think I explained that - it's the leading pin.
 
Originally Posted by Silk
Originally Posted by painfx
Why is there only 1 rubber bushing on the top slide pins and not on the bottom?


I think I explained that - it's the leading pin.


There are vehicles have top and bottom.
 
Interesting topic! What type of grease causes the rubber bushing to swell? When I did my VW and changed out the caliper carriers for larger ones to up my rotor size, I noted where the bushings were (top or bottom) before the swap. I used some Motorcraft silicone brake caliper grease I had but had heard to only use the TRW caliper grease or the bushings would swell. Any comments?

I like the idea above on why there is only one bushing (top or bottom) - v. interesting/wouldn't have thought of that.
 
You are okay with the Motorcraft silicone, the bushings are EPDM rubber which is not compatible with most oils and greases but silicone is harmless to it.
 
Originally Posted by TiGeo
Interesting topic! What type of grease causes the rubber bushing to swell?


Permatex green states they are compatible with rubbers and other brake parts, but I'm pretty sure it made my bushings expand and seize. I'm sticking with Silglyde now.
 
Originally Posted by Silk
Yes, and some have none, and Toyota have it on the trailing pin. Confusion will be your epitaph.


How come some have it on the bottom only?
 
Originally Posted by painfx
Originally Posted by Silk
Yes, and some have none, and Toyota have it on the trailing pin. Confusion will be your epitaph.


How come some have it on the bottom only?

It depends on how much dampening you need. But most cars have the bushing on the leading pin.
 
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