Do you *need* the caliper slider pin bushings?

[xBa380]

I got a question...

On toyota/scion vehicles, there are rubber o-ring bushings on some of the sliding pins for the calipers. On the front, only the bottom one I believe has it... On the rear, both do if I remember correctly.

When I did my brakes a few months ago I had big problems with the pins seizing up in the rear. Once I got them un-stuck, cleaned, relubed, replaced the pins and bushings, etc... I noticed there was much more resistance with the bushings on (I am sure by design)... Because the calipers were all seized up, there is more resistance than normal I believe.

Either way, they did slide properly after the fact but not as easily as the front ones. I removed the bushings and tested the operation without and they worked extremely well with little to no resistance at all.

But I figured that bushing had to be there for a reason so I made sure to keep them in and just lubed up as much as I could with sil-glyde (the permatex purple stuff seized them shortly after the first time... Don't use that stuff with any rubber).

My question is, are those bushings absolutely necessary? I plan to check/lube the brakes before winter again and want to hear some opinions on these... If they help the rear brakes function better (less resistance with the pins) should I remove them? When doing my dad's Prius brakes, I noticed his rear brakes had the slot for the bushings, but with no bushings present (nobody ever serviced them before me). So I am guessing it won't cause any damage if Toyota practice this on their other vehicles.

Just looking for some thoughts though... What is the function of these bushings anyway? Noise?

Thanks!

 

[tightwad]

They're there for a reason. Boss Kettering, who founded ACDelco, once said (loosely) "Parts left off cost nothing and cause no problems in service." So if the carmaker put in on, it's needed.

 

[xBa380]

I guess my question would be, why were they left off the rear brakes of the Prius? They have pins that have the notch in them to have the bushings, yet were never installed on those.

Just makes me wonder if they really are required due to that. If just for noise reduction, then I may just remove the ones in the rear if they are gunked up.

 

[heynow]

Could the rubber bushing serve as a seal to keep contaminates out of the lubricated area?

The Prius is built for MPG, so maybe they are left off for slightly reduced brake drag?

 

[JTK]

I don't recall if all my vehicles had the bushings only on the lower caliper slide pin, but I know only one of the two has the rubber bushing on each of my Honda's calipers. I always figured they were there to reduce noise/vibration.

I know in the case of my Honda, I had to get a pair of new caliper pin boots from the Honda dealer parts counter and the kit came with two boots and two bushings. They called it a "bushing kit".

Joel

 

[rcy]

Funny, I had the same experience on my RX400h. IIRC, the rubber bushings were only on the rear on were on the bottom pins. Even after buying new pins and bushings, I found that with the rubber bushing on the bottom of the pin, I could barely get the pin inserted. Maybe the lube I was using swelled the rubber?

Anyway, I just removed them and carried on and never had any problems. I will say that Lexus had a TSB regarding the bushings, showing that they were to be on the bottom pins only.

 

[vssjim]

As long as they don't rattle no problem, I have left them out when they swell up and won't slide and can't get new ones right away. I use silicone grease on slides and pins and that way it seals out water keeps them sliding and doesn't ruin rubber parts. Not all cars have those band type bushings on one of the slides any way.

 

[edwardh1]

my 2004 highlander has a drivers side front brake area clack/rattle noise at 93000 miles when I hit a lane divider dot at 35 MPH- no noise if my foot is lightly on the brake. the caliper bracket moves a very slight amount when pushed by hand. everything else seems tight, new oem pads and rotors 8000 miles ago.
I may pull the pins and take a look

 

[The Critic]

If the caliper slides too freely and has play, it may cause the pads to wear unevenly. Bushings swell because the wrong lubes are used. I would install new bushings and lube with the correct silicone paste or the glycol/soap lube that Toyota calls for.