Numerous caliper designs incorporate an insulating rubber bushing on one of the guide pins to prevent caliper knocking or rattling. These rubber guide pin bushings are made from EPDM rubber, and it is crucial to use a lubricant that is compatible with EPDM rubber. Let’s discuss why this is important to remember and what we use as lubricant in our own assembly room.

Product Release

10/12/2024

Written by Darren Caldwell

Grease or Silicone lubricant?

Using any petroleum based product such as grease will cause EPDM rubber to swell and the pin will seize in the bore. On the other hand rubber grease which is compatible with EPDM does not withstand the temperatures that are reached in normal braking. The best product to use is a silicone lubricant as used by O.E manufacturers. This is compatible with EPDM and is rated to high temperatures. Introducing Silicone Coolube…..PW33001

Why is keeping pins lubricated so important?

Should I lubricate the guide pins when I am doing a brake pad change?
The answer is yes. On a sliding caliper the guide pins are crucial
to the efficient operation and retraction of the outside brake pad.

Hot Tip

A caliper with seized or tight guide pins will wear the inner brake pad prematurely.

Can a guide pin have too much grease?

When servicing the guide pins it is important to clean out any old, contaminated grease and replace with new grease. Caliper guide pin to bore clearance is about .2mm which means that there isn’t much room for grease. Less is better…it literally only needs a smear of grease around the guide pin.

I have greased the guide pin and now the caliper bracket is
springing back.

This has occurred because there is too much
grease and there is air trapped in the guide pin bore as the boot
is sealing it in. To rectify this, use a blunt spike to release the air
from the boot whilst moving the caliper bracket back and forth the
on the guide pin.

Hot Tip

Air trapped in the guide pin bore will cause
premature outer pad wear.