# Need Help Understanding a Few Things on Rear Disc Brakes for '00 Celica



## amodoko (May 29, 2011)

I have a few questions regarding my rear disc brakes on my 2000 Toyota Celica GTS (I've attached images for clarification. The diagram is from the shop manual, and the photos are just some random images I've found online so people can get an idea of what the rear brake calipers actually look like. The photos are not of my calipers. My calipers are really rusty). I was going in there to replace the brake pads for the first time, and noticed it is setup a bit different than I have seen on other cars. I can change the brake pads, that's not the issue, but I don't know for sure how to properly service/maintain the brake parts. Normally, one thing I would do is add silicone paste/lubricant (like Sil-Glyde or 3M Silicone Paste) to the guide pins so they move back and forth easily, but these brakes are a tad different. They have brake pad guide pins that look like they don't require any servicing (they're just open metal bars that are exposed to the elements). Having said that, the brakes do have a bolt on one side (also called a guide pin according to some sources and labeled "47" in the image) that goes into a sliding bushing that can be lubricated. However, it looks like this sliding bushing only rotates and does not move back and forth like normal sliding bushings, unless I'm understanding something wrong or my brakes are screwed up (my brakes and brake parts are really rusty). 

I attached an image from the shop manual that describes where to lubricate the bolt/parts in question. The bolt or guide pin I was referring to is labeled number 47 in the image. That bolt, "47," goes into a "sliding bushing" that then goes into some rubber "dust boots," as the diagram shows. There are two of these. It shows that it can be lubricated (the black arrows indicate lubrication needed) as part of the maintenance, but I'm still confused as to how those parts work. Bolt 47 locks into the opposite side of the brake apparatus when it is tightened, and becomes immobile, so the bolt can't move I think. The only thing that I think moves is the sliding bushing. When I looked at my sliding bushing, it looked like the bushing may not actually slide back and forth either (even though the term "sliding" is in its name). The bushing ends up being wedged between two metal parts once bolt 47 is tightened down, or at least it looked like that. I believe the bushing only rotates, so you can open up the caliper like a clam shell when doing brake service. I'll probably have to examine it a bit more to fully understand its function and how it's supposed to work. I'm just trying to understand a bit more about it so I can figure out how to properly service everything and getting it to work as it was intended to. A lot of my brake parts are pretty rusty and I'm not sure how things are supposed to move and/or whether I need to replace certain parts. 


My bolts, labeled 47, are pretty rusty and so is the inside of the sliding bushing. The brake caliper still rotates open fine, but it doesn't slide back and forth it seems on the "sliding bushing", and I'm not even sure it is supposed to based on how the caliper is setup. I understand though, that the brake pads need to move a bit on the brake pad guide pins (those are separate parts as indicated in the diagram/image), but that's not what I'm currently interested in. Although that seems like a weird design that would be prone to binding.

So I guess my question is, do you know if the sliding bushing is actually supposed to slide back and forth? Or is it just supposed to rotate so the caliper can rotate open, once one of the two bolts are removed, kind of like a clam shell when doing brake service? Do people generally lubricate these parts when a brake caliper is setup this way? Thanks again for any advice


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## iamrfixit (Jan 30, 2011)

I don't have experience on your specific vehicle but typically those should slide back and forth pretty easily with finger pressure. They must be able to slide in order for the outboard pad to brake and release evenly with the inboard (piston side) pad. When they don't move smoothly you could experience a dragging brake due to the outboard pad being unable to release fully, or uneven pad wear from the inboard pad doing all the work. It basically tries to deflect the rotor over into the outer pad rather than pulling the pad into the rotor so it really isn't too good for either part. 

You should be able to remove the rubber boots and disassemble by driving the bushing out. Clean up the bushing and the bore well and lube thoroughly with some silicone caliper grease. If the boots aren't in good condition get replacements in a caliper repair kit or it really isn't too difficult or expensive to just install a re-manufactured (or new) replacement caliper and get rid of all the rust issues.


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## ron45 (Feb 25, 2014)

Get a rebuild kit.
Take the calipers apart.
Put all the metal including bolts etc., in a bucket of white vinegar overnight.
In the morning lightly brush them off then air dry.

Reinstall according to the direction.
To give you some insight, here's


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## ron45 (Feb 25, 2014)

So Private Pyle you want to learn how to make it pretty. 
Sir yes Sir.


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## amodoko (May 29, 2011)

Awesome, thanks guys. It probably does need to slide back and forth then. I must have not looked at it correctly or maybe it does need to have some parts cleaned/lubricated/ or replaced. I'll have to go and look at it again and make sure it all works. The videos that ron45 posted are awesome, both of them lol. I'll post an update when I work on it again to let you know how it all goes. I may have some more questions if you guys don't mind. Thanks again, much appreciated


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## bfletcher7 (Jan 16, 2016)

amodoko said:


> The only thing that I think moves is the sliding bushing. When I looked at my sliding bushing, it looked like the bushing may not actually slide back and forth either (even though the term "sliding" is in its name). The bushing ends up being wedged between two metal parts once bolt 47 is tightened down, or at least it looked like that.


I'm not a mechanic, so take this with a grain of salt but I hold the opinion--just as you suspect--that the bushing is fixed and, rather, the caliper slides along the bushing as the piston compresses. If both your inner and outer pads are worn then the caliper is (or at least was) sliding along that bushing. But it has been my experience that on a sliding caliper both pads do not wear exactly even. Since the caliper floats along the bushing is possibly the reason it holds the name sliding bushing. Good luck!


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## amodoko (May 29, 2011)

That makes so much more sense. I'm an idiot. I don't know why I wasn't thinking properly. Thank you for that. That HAS to be how it works. I appreciate that information. I just can't believe I didn't figure that out for myself even though I had the calipers right there in front of me, LOL.


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## ukrkoz (Dec 31, 2010)

You are not an idiot.
Caliper MUST slide back fore about 6mm. 1/4 inch. Or, it will eat through brake pads. It should slide on guide pins. Looks like you have a stationary pad and floating pad, one against the caliper. If caliper does not slide, you WILL have brake trouble. Re-lubricate every tire rotation, which should be about twice a year.


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## amodoko (May 29, 2011)

Thanks! I haven't gotten a chance to work on it again, but it looks like I'll have to just remove those rubber dust boots around the bushing on each side, take the sliding bushing out of the brake caliper, lubricate the outside of the sliding bushing itself and/or inside of the hole the bushing slides in with silicone lubricant (I'm using Sil-Glyde), and then push the bushing back into it's hole in the caliper, and put the rubber dust boots back... and I believe I should be good to go with regards to that maintenance issue. Thanks everyone


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## ron45 (Feb 25, 2014)

The only dumb question is the one not asked.

Nothing like seeing, almost as good as hands on.

Good tips and allows you to see your answer.


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