Use silicone grease (Sil Glyde) to protect caliper boots and guide pin boots----a good idea?

2 years ago I replaced my calipers with Raybestos OPTI-CAL line of brand-new non-remanufactured calipers.

A quick inspection reveals that the guide pins have already been torn and the caliper piston dust boot is cracked and torn as well--------2 years!!! The OEMs that it replaced after 12 years of service were still good (the rubber boots that is.)

So, this unit still works but I’m going to pre-emptively replace it with a CardOne remanufactured unit (wearing the WEAREVER brand) from Advance Auto.

Question is: should I generously apply Sil-Glyde to it (even on the outside.)

YES, it will be covered in brake dust but that won’t impair its functionality

.The problem is,if you put a coat of this grease on the boot,It will wash away after a few rainstorms.It will not harm the rubber because its synthetic.

The amount applied won’t make a difference.

It’s even moisture proof!


So, that’s a “YES” ----- yyou do think it’s a good idea ?

that’s why it is better to redo old/rusty OEM calipers rather than buy aftermarket replacement of unknown quality

most local stores carry piston o-ring and boot kits for very cheap, the additional work takes minutes

Explain how you’re able to rebuild a caliper in minutes?


last time I did that on 2007 Altima (assuming caliper is removed and sits on the bench):

  • clean from the dirt with wire brush and compressed air
  • remove/clean sliding pins, clean with brake cleaner
  • put a piece of wood where brake pads used to be
  • use compressor to pop the piston
  • remove boot and piston o-ring
  • clean with brake cleaner and no-lint rug
  • new o-ring comes in with a little bit of silicone grease
  • attach boot on piston, slide in, attach retainer
  • grease sliding pins, attach boots, slide in
  • DONE

I assume calipers are not seized or damaged

remove / reattach / bleed brakes - these operations are the same if you replace calipers or remanufacture them, so I do not count them in “minutes”

What do you do if the bleeder breaks off?

What if the caliper bore needs honing?


You beat me, @Tester, but you work on it professionally.
I’m a weekend warrior mechanic, but in my defense I can tell I’m doing it in a garage, not under the tree :slight_smile:

The message I wanted to deliver was simple: it’s better to keep OEM if that’s an option.

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I’ve never encountered a rubber-parts problem on my brake calipers before, but I have on CV boots. I finally figured out that the deterioration of the CV boots was caused by inadvertently getting oil, solvents, and WD 40 on them. Since then I’ve adopted the practice of cleaning the boots and their folds with mild soap and warm water using a paint brush followed by a water rinse at every oil and filter change, and never had much of a problem with boot deterioration since. The inner CV boots on my 27 year old Corolla are original to the car. I expect you’d get best results just by keeping the rubber parts on your calipers clean, and otherwise applying nothing.

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Sil glyde or pure silicone grease is the generally preferred stuff for the rubber parts in your brake caliper components. However if the boots on your slide pins are torn I would probably go ahead and get those replaced.