Brake caliper pin hard to insert, being pushed back out

ymg200ymg200 Member Posts: 1
edited August 2015 in Saturn
Hi all.
I drive Saturn SC-2, 1999, 165K miles.
I am a DIY guy. I have replaced pads and rotors before in the same car and never noticed this problem.
Lower caliper pin (driver's side) was hard to take out, and now it is hard to insert it back in. What is unusual is that the pin is being pushed outside when I try inserting it.
It feels like the pin traps air inside the guide channel, and I compress air as I push the pin in, and compressed air pushes the pin back out. This happens only on the driver's side. The other caliper takes the pin with no unusual resistance.
I have cleaned the channel with the cu-tip thinking that it might had excess of grease, but it is relatively clean inside.
There is the rubber plug or stopper at the end of the channel. I tried prying the stopper out, but did not succeed because I did not want to apply excessive force.

I googled, but did not find anybody else having the same problem of the caliper pin being pushed outside when attempting to insert it.

What should I do in this case?

Should I pry the rubber stopper open? Is it designed to be opened?

Thank you.


  • thecardoc3thecardoc3 Member Posts: 5,728
    Cleaning and lubricating the caliper slide hardware is a normal procedure that is part of a brake service. Those rubber grommets/sleeves/ bushings are replaceable as part of a kit. In areas of high corrosion rates (the rust belt) it is often wise to simply install remanufactured calipers. By the time corrosion on the outside of the rubber sleeve gets bad enough to squeeze it undersized, (which is likely what is going on) the same is happening to the caliper piston surface, and the caliper bore where the main square cut O-ring resides.

    You can make a temporary difference in the caliper slide by first choosing the correct drill bit. (fit the caliper pin into the drill index to identify the matching bit) and then use that drill bit to ream and clean the inside of the bore and the bushing. Wire wheel clean the caliper pin and then apply a silicone based high temperature lubricant, but use only enough of it to do the job, too much can cause some serious problems. Do NOT use any other style brake grease unless is specifically states that it is for use on rubber components. The wrong grease will make the rubber swell and that will cause the problem all over again.
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