Sticky Ear Question - Speak Up!

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Having a bit of trouble stripping (and understanding) my offside brake caliper ears.

The "pins" (i.e. the bolts that hold the caliper on) are out. They came out easily, because I put silicon grease and PTFE tape on them last year, when I stripped the other caliper, which had a stuck piston. I ran out of time to strip this caliper then.

The main current problem is with one of the yellow metal (finish?) bushings, which is stuck fast.



Plan A was to use a spare-tyre holdown out of an abandoned Corolla as a press, but the plate on the end wasn't strong enough. Hopefully its backed up with a nut in use, otherwise I wouldn't want to be in the back of a rolling Corolla estate.



Plan B used another spare tyre holdown (either from the Skywing or Sierra, can't remember) with some washers and sockets..





Bit wimpy. I'll try and rig something better, but the damage to that improvised thrust washer suggests this bushing isn't going anywhere with this technique alone.

So serious heat/cold (perhaps in conjunction with a vice/big hammer) seems to be indicated, or take it to someone with a hydraulic press, or a new caliper, if I can get one.

HOWEVER (cue red face / schoolboy error icon) I'm having trouble understanding the consequences of this stuck bushing, especially since the brakes seemed to be working OK.

The bushings needs to move freely on the pins, and they do.

Do the calipers need to move freely on the bushings?


IF I understand it correctly, a stuck bushing does restrict the movement of the caliper.

If the caliper wasn't moving at all, I'd only have one pad effective. Perhaps there's enough movement between the end of the bushing and the caliper to bring the other pad into play.

The pads aren't currently very worn, but in this scenario, as they wear, the other pad will become ineffective. Shims might buy more time.
 
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Soak it with penetrating fluid and use a bench vise with a big deep socket on one end and a washer on the other side to protect the bushing from jaw damage. The busing needs to slide freely in the caliper.
A smoke wrench and a BFH or a press is the easier way, then get a new bushing.
 
Originally Posted By: meborder
I'd try some heat and an air impact hammer.

Always amazed what a little hammering / vibration can do.


Checked my pockets. No air hammer or compressor. Perhaps I left them in my other jacket.

I THINK the art dept might have air chisels (for sculpture) and vices, so if I ask nicely (and dress appropriately) I might be able to get access.

man-repeller-salvador-dali-style-a-continuous-lean-3.jpg


In Tapei for a couple of days but I'm thinking when I get back on it I'll try jacking it up under the car as a heavier duty improvised press.
 
You'd be money and time ahead buying a cheap air chisel and compressor than trying to press it out with brute force.

Used to be all that stuff was made in Taiwan.... Now its mostly china.


I'd locate a replacement caliper before attempting to horse it out of the caliper. Very likely to need it.

JMO based on my experience.

I once worked on a frozen shock bolt for an hour with a hammer and a punch. Wouldn't budge because the rubber bushing would absorb the energy and wouldn't let the bolt move free of the metal bushing. Finally remembered I had an air chisel and it did in less than 3 seconds what I was unable to to do by hand for more than an hour. Just a tool everyone should have in your bag of tricks.
 
Originally Posted By: meborder
You'd be money and time ahead buying a cheap air chisel and compressor than trying to press it out with brute force.


Time probably. Money I don't get.

I quite like buying tools, BUT I don't have a lot of storage space (I have one room and half an office altogether), I certainly don't have a dedicated workspace/workshop, and I often don't have power where I end up working, or transport to conveniently get heavy equipment to the car when its immobile.

I mostly work on the campus, where I can sometimes get power to the car, but I've been getting a bit of flak about that lately (El Presidente Nuevo himself has apparently expressed displeasure). If I have to work off campus there wont be any power available.

This might be the last year of my teaching contract and I may then have to leave the country.

These factors all currently contra-indicate buying anything I don't have to.

I do have an electric "hammer drill" which I suppose might give some useful vibration in some circumstances.
 
Hammer drill and a power inverter gets you there as well. Particularly if you can turn off the rotation.

Can you find a 700w inverter? I've run drills, grinders and my electric impact off of mine. Even my 500w halogen work lamp. Never without power again
smile.gif
 
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put a bolt in it (anything that'll fit and hammer the head of the bolt until the slider starts moving.

Yes, the caliper should slide, but I don't understand how it looks like new yet doesn't budge.
 
Originally Posted By: Jetronic
put a bolt in it (anything that'll fit and hammer the head of the bolt until the slider starts moving.

Yes, the caliper should slide, but I don't understand how it looks like new yet doesn't budge.


Much like my stuck shock bolt example, I think the rubber bushing will just absorb the energy of the hammer blow and do nothing. Assuming you don't bend the ear of the caliper.

Can you take the caliper into the art department and use their air chisel for 5 seconds? Thats about all it would take.

What kind of car is this again?
Wonder how hard it would be to ship a part to you person-person. I bet a new caliper here in the states is pretty reasonable if the shipping can be done at a reasonable price.

I'd help get you a new caliper.
 
The corrosion supported the weight of the car easily, including a bit of hammering on a suspension plate above it. There isn't any rubber on the bushing to absorb shock, it was just well stuck on.

There are a couple of Stuart tanks in a playground in the nearby city (only considered light tanks by mid/late WW2, but probably heavy enough) that I thought I'd try, but on the way there came across a shipping container in use as a workshop, mounted on steel wheel hubs at the corners to give it some height. That, with my (5?) ton bottle jack and a socket, did it.

I pressed it back and forth a bit with that, then finished it off with hammering, tapping on a wall, and finally drifted it out using the end of the pin around the edge of the end of the bushing.

Thanks for all the suggestions. Incidentally I've read somewhere that most standard 120V AC drills will work OK with 12V DC, but have never risked trying it.
 
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Not really pitted as such. Just looked like surface rust but once cleNed up with foil nearly all the anodising was gone. I.d guess most of the rust came from the ear, which isn't very visible. Pretty big bang when it let go.I thought I cleaned it up ok but when I tapped the greased and PTFE wrapped bushing back in its drove more rust out. Now moves freely
 
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