what is the purpose of the end of the caliper bolt

[bowlofturtle]

I have a stripped lower rear caliper bolt on my infiniti.

I have two diffrent types of bolts. The upper bolt was a normal looking end, the lower bolt looks similar to the item i have in the picture. But when i order the pair from raybesto, both came with the lower bolt design. BUT there is a rubber black thing at the END of the bolt. Its not present on these bolts. I dont know if there is a purpose and where to get it. As nissan doesn't have a part number. And they said i would have to order up a bolt and see if they come with one.




http://i5.photobucket.com/albums/y183/t2urtle/IMG_20120608_144755.jpg

 

[NHGUY]

Sounds like a guide pin boot kit.Seems Raybestos doesnt offer one for this.Wagner does.

 

[bowlofturtle]

whats the purpose of this boot-like item.

Why would nissan only have them for the LOWER caliper pin and not the top?

 

[artificialist]

Originally Posted By: bowlofturtle
whats the purpose of this boot-like item.

Why would nissan only have them for the LOWER caliper pin and not the top?

I don't know why the 2 bolts are different, but I 2 different types of bolts on many cars, not just Nissans.

 

[yonyon]

I think you're not talking about the dust boot, but the pin bushing. I suspect it's there primarily to reduce noise and may also reduce wear inside the bore. I'm not sure about that though. I am sure that your brakes will function just fine without the bushing and going without a bushing is better than using a bushing in bad condition that presents excessive resistance to sliding. Hopefully someone else will be able to shed more light on this.

 

[Trav]

Quote:
I suspect it's there primarily to reduce noise

Yep some small GM SUV had a problem with them, they made noise on rough roads, they came out with a new part# to cure it.

Do not use aftermarket bushings, many times they are too tight the brake will not release fully right away causing a slight groaning noise from the caliper when starting off when cold.
If they are too loose they will rattle over bumps, get new ones from the dealer if the originals are shot.

 

[ronbo]

Had the same problem with a Toyota RAV4. A rubber washer sleeve on the front of the pin. Removed it since it bind the pin and prevented sliding. Think I read it's there to prevent brake noise and chatter.