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BoxerRebellion

'87 GL Front Caliper Pistons Not Depressing

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And here we are once again.

Smack in the middle of a rotor/pad job.

 

For.... Whatever reason, I can't for the life of me get the Front-Left caliper piston to go back into it's home.

I've repeatedly serviced brakes on five different Subarus throughout my life. I've yet to run into this problem.

Even broke the handle on my brake depress tool. Sweet.

 

Opened the bleed valve, pulled the roof off the master cylinder, nothing.

Rock solid won't budge.

 

After scurrying around the interwebs I read multiple articles regarding vehicles having caliper pistons that twist in.

Does the '87 GL have these twistyroo pistons?

Is that the problem?

 

Who here knows something I don't?

 

Any info - greatly appreciated.

Thanks.

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Yes the piston must be rotated inward (clockwise)

 

All subarus from 70's on up through the last of the loyales are setup this way.

 

Not sure how you did brakes on the others.  You may have stripped the threads of the self adjuster post on those ones.

 

There is a little cube shaped tool you can get that fits on a 3/8th drive ratchet.  less than $10

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Turn the pistons. Make sure the parking brake is off or disconnected. Try pushing down and turning. it will engage a thread as it turns. You may have to tap the face with a hammer to allow it to move enough to engage the thread.

 

You may be able to accomplish this with just a channel plier. You should be able to find the caliper tool at an auto store. It looks like a metal cube that goes on a ratchet and had nubs on each face for different styles of calipers.

 

This design is typical of rear parking disc only brakes. But subaru front brakes have been this way form 70's models all the way thru 94 with ea82's

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the metal cube tool at a auto parts store is mighty handy for this job.  can be turned with other things but if they're tight it's grueling and seems to take a decade.

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Sigh... I slightly... Slightly expected this.

Probably explains the odd looking shape and surface area of the piston.

And the other Subs were newer Legacys and Imprezas.

 

Good information from the both of you.

I really appreciate it. Really do.

 

I'll try the channels first, then go from there.

Learned my lesson.

Guess this is the best way.

 

Thanks again guys.

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Make sure the quarter circular opening on the piston is oriented towards the front - back of the vehicle.  This will help you to fit in the little notch on the pad.

 

Good luck,

 

Sam

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Make sure the quarter circular opening on the piston is oriented towards the front - back of the vehicle.  This will help you to fit in the little notch on the pad.

 

Good luck,

 

Sam

To clarify a little, the pistons have to be rotated to a particular orientation (well, 2: 180 degrees apart) in order to properly fit the brake pad.  Neglecting to do this will turn out VERY BAD.

 

I have used all sorts of improvised tools to turn in the pistons:  Vise grips (just loosely pressing the nose of the jaws into the channels and spinning with a screwdriver stuck crosswise to the V-G handles) was one of my more common make-dos.  I have the cube (cost about US$10) and now have a proper brake service set.

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Just get new calipers. Not that expensive from Rockauto and you have piece of mind of knowing your calipers will be working correctly.

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I have never had a Subaru caliper fail.  They have had their rubber boots rot away, but kept working while I tried to locate replacement parts.  New calipers seem an unneeded expense if just replacing pads.

Edited by NorthWet
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As it turns out... The "piston cube" worked flawlessly.

I was kicking myself when I realized how easily the pistons recessed with the proper tool.

As opposed to ...BRUTE FORCE COMPRESSION.

 

This is the first rig I've been involved with that had such a brake setup.

 

And @NorthWet, I caught onto the fact the piston had to be turned to a form of "TDC"

I suppose it makes some sense, being that the piston is housed in a shell that is cabable of unwanted movement during driving.

Didn't see it at first, though shop lights revealed the little nub on the inner pad was hanging up.

 

Tricky little setup.

Bizzarro.

 

I now see why this style of piston is no longer in use.

 

In conclusion, learned a valuble lesson.

-Without damage occurring from a lack of needed knowledge, that could only be gained from such experience.

 

I thank all who chimed in.

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Just get new calipers. Not that expensive from Rockauto and you have piece of mind of knowing your calipers will be working correctly.

 

 

 

Ever actually priced new calipers for an older subie?

 

And c'mon,  replace a good working genuine Japanese part for some chinese knockoff.....just because you don't want to deal with using the correct tool?...........no thanks

 

Just do the job correctly....like apparently the OP of this thread did.

Edited by Gloyale
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Dumb

 

Ever actually priced new calipers for an older subie?

 

And c'mon,  replace a good working genuine Japanese part for some chinese knockoff.....just because you don't want to deal with using the correct tool?...........no thanks

 

Just do the job correctly....like apparently the OP of this thread did.

Yes I have not only priced, but bought. They work flawlessly. You have no idea what my experience with brakes, if I just didn't want to use the correct tool, or not, is. Thanks for the personal attack and veiled insult tho.

Edited by jonas

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Dumb

 

Ever actually priced new calipers for an older subie?

 

And c'mon,  replace a good working genuine Japanese part for some chinese knockoff.....just because you don't want to deal with using the correct tool?...........no thanks

 

Just do the job correctly....like apparently the OP of this thread did.

This is typically out of lack of knowledge to properly service them, or by them being ruined already from the wrong service.

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OP, this type of piston is probably still in use.  The reason it is odd is that these models use a front-parking brake rather than the more common parking brake on the rear  All of the bizarreness is to accommodate this "feature".

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Yes I have not only priced, but bought. They work flawlessly. You have no idea what my experience with brakes, if I just didn't want to use the correct tool, or not, is. Thanks for the personal attack and veiled insult tho.

 

 

Not personal in the least.  I don't even know you. 

 

My response refers strictly to the topic of this thread and the ideas discussed......not about you.

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Funny.

 

Personally, there would have to be a good reason for me to unseal a brake system to install a new caliper.  Call me lame... (pause) ... but I have the hardest time properly bleeding a brake system by myself.  Which is how it always turns out:  I am the "The Little Red Hen" of making stuff work.

 

Cheers! 

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