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Today I was servicing my front brakes and one slide pin on each side was frozen in the bracket.

After removing and cleaning everything I went to grease the pins but realized I ran out of silicone paste that I normally use.

I did however have some left over dielectric grease from a tune up and used some of that. Then I got wondering about the differences as I believe dielectric grease has or is a form of silicone?

This brings me here inquiring. Can they be used I interchangeably? Like silicone paste on spark plugs or dielectric grease on slide pins etc

Btw my brakes felt better so for now all seems well with the dielectric substitute on the slide pins

user58423
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3 Answers3

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Brakes become hot. Very hot. 300°C (600°F) and more is easily achieved at the disks after a hard braking from high speed.

Most greases become quite thin at a higher temperature, and start to creep away from where they previously have been applied to. And the last thing you want is a grease which creeps onto the surface of the braking pad.

Further more, the rubber used at the brake system is made to resist brake fluid, but often doesn't resist mineral oils and greases.

Silicone grease is said to withstand high temperatures, but since every grease has its very own behavior when hot, I would not expect that each silicone grease stays thick enough for the temperatures of a brake. At least, it should not harm the rubber.

Dielectric grease seems to be a kind of silicone grease, which is explicitly made for higher temperatures like at the spark plugs. So I don't have any objection of using dielectric grease vs. normal silicon grease.

But I would strongly recommend to use a special grease for this purpose like PlastiLube for exactly this purpose, because you never know how a random grease behaves at the brakes, even if it's made for high temperatures.

sweber
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So I cant say for sure I'm no expert and I actually made this "mistake" already I thought they were the same when I did my breaks last. Well that was about a year ago and my wheel bearing went bad and I had to take the breaks off to replace it. Well when I had it off I decided to check my guide pins and they still were sliding smooth, so I'm not sure about the long run but so far for me I haven't had a issue.

Shane Youngs
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Are silicon and dielectric grease interchangeable? NO They are designed differently for different purposes. Dielectric Grease is is non-conductive. Great for keeping electrical connections free from corrosion, while protecting rubber, such as spark plug boots. So slather dielectric grease on every bulb and fuse.. Silicone grease has petroleum distilates. Real nasty on plastics and especially rubber based seals. And silicon grease cures and goes tough, while being great for the backside of disc brake pads,good to 1000' F Another 3rd is Synthetic Grease. 3M is pricey but the gold standard.This is excellent for inside disc brake slide pins. And lubricating door seal rubbers. It does not cure. And is good for high heat, like 400'to 800'F, depending on the manufacturer. So your wheel bearing grease has more metals,lead, lithium,and graphite .. so better for wheel bearings, and high friction loads like ball bearings. Be very ccareful to not cross contaminate.

Old and Siff
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