Noisy Brake Caliper on my Miata

[—Martin—]

Yesterday I greased one of the sliders (sorry if that's not the correct term) driver's side rear brake caliper because it started making noise again. I "borrowed" this pic of a Miata brake caliper from ebay and circled the slider that I greased. The boot on mine doesn't seem to fit quite as nicely as the one pictured, so I assume water is washing the grease away. This is the second time I've greased this part, the first time was about a year ago.

Can/should I replace the boot? Use marine grease?

rearcaliper.jpg

[The Driver]

Bueller, Bueller, anyone, anyone...

[GripFTW]

Yesterday I greased one of the sliders (sorry if that's not the correct term) on the driver's side rear caliper because it started making noise again.

What kind of noise is it making? Squeak, squeal, grind, crunch etc. Obviously it makes the noise when braking. Does it do so all the time or under specific circumstances?

Can/should I replace the boot? Use marine grease?

Yes you can replace the boot. I would check the pins also to make sure they're not bent or overly worn and stick with brake specific grease.

Napa gives me these parts for the rear caliper boot.

Caliper Bushing Kit - Rear
Part Number: UP 83030
Product Line: NAPA Ultra Premium Brake Parts

[—Martin—]

Seems weird but it kinda sounds like the tire rubbing on something. I hear it while braking and also for the first few feet when taking off from a stop.

I will pick up some synthetic caliper grease and a maybe new boot next time I go the parts store.

Thanks.

[— kung fu jesus —]

I agree with Grip. Those sliders need to be checked annually. More frequently if used under duress. Those little boots crack or tear or melt and all kinds of crap gets in there. The grease I have used over the years is Napa's Sil-glide. I have had a 4-5oz tube for 10 years. It is a high-temp silicone-based grease specific for brake applications.

If the slider is caked or corroded, use some emory or sandpaper to clean it. While you're in there, inspect the piston boot. check for cracks in the rubber, leaks, etc. If you see this, you will need to rebuild it or get a reman.

I assume you already know about the grub screw in the back of the caliper for adjustment.

Hit me up if you need any further explanation.

[—Martin—]

Thanks, kfj!