100 series brake caliper pins

[Jfoofighter16]

I searched but did not see anything adressing my question in particular here so sorry if this is a repeat post/question. I have an 03 and was replacing rear brake pads/rotors and went to clean/grease caliper pins and noticed the one is metal and the other has a small rubber boot on that had failed/seized up and i replaced all pins/boots at the time with OEM parts but i see many posts about this caliper pin with the rubber boot seizing up. It seems like there should just be two of the all metal caliper pins.

I wven had the dealer print the parts spec page and the all metal pin is labeled as the "main" pin and the one with the rubber boot is the "sub," seemingly implying that it's bearing less of the load here?? Either way the rubber boot seems to get in the way of smoother movement woth the caliper in general and since it wears over time I'm considering just putting in teo of the all metal pins and just not doing the pin with rubber boot at all.

Can anyone tell me purpose for the pin with the runner boot or why i shouldn't just replace it with the all metal caliper pin like the other one is anyways?

Thanks!

 

[cmck]

I going from memory here. There are two guide pins that allow the single piston caliber to apply clamp pressure from both side onto the rotor, while keeping things in alignment. They both have rubber sleeves (memory) and both tend to get stuck over time. They can be cleaned, re-greased and generally put back in shape with some basic effort. The rubber boot basically keeps the grease hanging around and the sliding movement happening.

My powerstop rear pads have these little boots included. I’m going to do the rear brakes in the next few days and will confirm my memory.

 

[Jfoofighter16]

On my LC and in the spec sheet i o ly have one pin with the rubber boot and another oin that is all metal. I.e. 2 pins per caliper but 1 is all metal and has no groove for boot to even go there and the other 1 pin does have the rubber boot. I am proposing just ditching the pin with the rubber boot and instead having two all metal pins.

 

[cmck]

I’m 1999, there was a redesign on some aspects for 2003. Maybe 99 and 03 are different...

 

[CanadianRockyCruiser]

I believe the runner boot will:
-keep the bore lubricated (like a piston ring)
-keep debris out of the bore and grease in
-prevent vibration and un-even brake pad wear

I'm not sure why there aren't two of them (maybe someone else can chime in. My 2001 only has a bushing on one guide pin, despite two guide pins per rear caliper.

 

[Porter]

Not sure how many miles you have on your calipers, but for approx $70 after core return, you can get remanned Eclipse calipers at NAPA. These are OEM Toyota units, factory stamping is identical, refreshed and ready to go. The rears on my 99 were needing replacement at about 310k last year (stuck piston), and I just replaced the fronts at 326 k last week while doing a bearing repack. Fronts were still working, but for $70 per, seemed like the 20 year old units did their job rather well and could use retirement. YMMV!

 

[badlander]

I think the op is referring to the rubber sleeve on the pin, not the outer boots. The purpose of the sleeve is to hold the caliper from rattling which it would on bare steel pins. You absolutly DO want to use those pins with the rubber sleeves on them. Also, if the holes which they slide into are properly cleaned of any rust and the holes and pins are properly lubricated with brake grease, and as long as the outer weatherproofing boots are intact, the pins will perform their jobs and will not seize up.