[Neptune!]

I am replacing the rear brake pads on on 2015 Outback. While waiting for parts I accidentally activated the parking breaks. Since no pads were in place to stop the calipers from extending, they extended beyond normal range. I cannot seem get the calipers compressed back into place now. They seem rigid and not willing to compress.

Any ideas?

 

[gen2lover]

If they are not leaking, you may still have a fighting chance to save them. The bore seal is a square cut ring, and it's designed to rock slightly as the piston travels. When you release the brakes, the seal rocks back to it's original shape, taking the piston with it. If the piston travels past the groove where the seal sits, it will be much harder to push it back and you risk damaging the seal. Have you tried to loosen the bleeder screw and trying to push the piston back in with a c-clamp? Perhaps the parking brake circuit is still allowing some pressure to reside in the circuit, so loosening the bleeder will eliminate that.(Obviously, make sure you have an old brake pad or something else to spread the load from the clamp to the piston) If you can get it to go back in and you see any fluid leaking around the dust seal, replace the caliper(s). Check afterwards to be safe by assembling the brakes onto the rotors and fire it up, then give the pedal a few moderately hard presses. Any leaks, replace. If you are brave, inexpensive aftermarket seal kits are available.

 

[Neptune!]

Well it would appear that I really screwed it up by accidentally hitting the parking brake while rear brakes were apart. Fluid is leaking and pistons are loose. In fact ball bearings and little springs fell out. Not sure if I can just get these reloaded somehow/somewhere or if I need to purchase all new units. What a simple obscure thing to really screw the works up. I have now removed the rear brakes entirely. If anyone hhas any ideas on how to avoid paying for new calipers, like how to get these reloaded, I surely appreciate it.

 

[gbhrps]

Neptune,

All is not lost. You have to understand that the rear brakes involve two separate systems, one mechanical (the emergency brake shoes) and one hydraulic (the calipers). The only part they share in common is the rear brake rotor. No springs or ball bearings will come out of the caliper, and perhaps a spring may come out of the emergency brake shoe assembly, but no bearings. If you left the rotor in place, when you put the electronic emergency brake on, it can have no effect on the caliper or its pistons.

If the rotor wasn't on the wheel studs seated correctly, or not at all, then its possible the emergency brake mechanism may have popped a spring off.

Here's a link to a video that shows how to get the pistons back into the caliper using an air gun. Using more air than the guy in the video does, its easy to do, and I've used it a hundred times. Piece of cake once you get the hang of it. Type this into YouTube search bar: "Capri Brake Piston Install"

Also, check out YouTube videos on Subaru's for brake jobs. They'll help you a lot.

Lastly, download the Factory Service Manual (FSM) for the 2014 OutBack from this next link. It'll take 15 minutes to download in pdf format, but it has everything you will need to service your 2015, except for maybe some of the electronic gadgets that weren't available in 2014. Unfortunately, this site for the FSM doesn't have the 2015 - 2017 manuals, but the 2014 will work just fine for what you'll need. Find your year, click it, and then just keep clicking the sections you need until you get to the end, and download it. Good Luck!

Type this into your search engine bar "jdmfsm.info/Auto/Japan/Subaru/"

 

[plain OM]

Neptune,

All is not lost. You have to understand that the rear brakes involve two separate systems, one mechanical (the emergency brake shoes) and one hydraulic (the calipers). The only part they share in common is the rear brake rotor. No springs or ball bearings will come out of the caliper, and perhaps a spring may come out of the emergency brake shoe assembly, but no bearings. If you left the rotor in place, when you put the electronic emergency brake on, it can have no effect on the caliper or its pistons. . .

2015 does not use the two systems involving separate brake "pads" and "shoes" acting separately on different parts of the rotor. Instead, there's an electric parking brake "actuator" on the rear brake assembly that uses the same pads as the regular driving pads to hold the rotor. (See attached.)

That's why, just as Neptune! described, when the parking brake was activated with the caliper off the rotor, the piston was pushed out by the parking brake actuator.

I guess that's one reason the 2015 FSM says to disconnect the battery when servicing the rear brakes --- it avoids the possibility of the parking brake being activated and pushing the caliper piston out of it's cylinder.

 

[BadTrainDriver]

Well it would appear that I really screwed it up by accidentally hitting the parking brake while rear brakes were apart. Fluid is leaking and pistons are loose. In fact ball bearings and little springs fell out. Not sure if I can just get these reloaded somehow/somewhere or if I need to purchase all new units. What a simple obscure thing to really screw the works up. I have now removed the rear brakes entirely. If anyone hhas any ideas on how to avoid paying for new calipers, like how to get these reloaded, I surely appreciate it.

Put the wheels on, and have the car towed to the dealer. No offense to you personally, but if you've screwed it up this far, do you really trust yourself to "properly" put it back together? Man up and admit defeat. There is no shame, and it could save your life. Brakes are not something to half ass.

 

[gbhrps]

Plain OM,

Thank you for the update!
I've never seen this kind of setup on any vehicle before in my life. Subaru certainly didn't make the change in the interests of economy for the owner. It looks to be engineered to ensure, that other than pad replacement, you have to go to the dealership to fix/replace a sticking piston.



Neptune,

Follow BadTrainDriver's advice and tow the car to the dealership.

 

[Neptune!]

Well here is an update. All I did was accidentally touch the parking brake switch after not removing a battery cable. Pretty simple mistake that results in big costs.

There is not way I or a Dealer, as I am told by the local dealer, can get the piston back in place. There simply is no stop mechanism for the electric brake when it is not on the rotor. The electric screw, similar to a worm gear, spins until the pistons rolls off the end.

New calipers are VERY expensive and hard to find. Local dealer wanted over $900 for the pair. I found a dealer in Illinois for about half that. Had to have a pair shipped from California warehouse to an Illinois dealer then to me. No core charge either. Subaru told me to throw away the old calipers.

No I am not admitting complete defeat. Certainly did screw up the works by activating the parking brake by mistake. Brakes are pretty basic. It was not my lack of knowledge of brakes it was my failure to disconnect the power and then my bad luck to touch the electric parking brake switch. Note, almost all mech repairs that involve a part that has power recommends disconnecting the power. I should have known better.

After almost two weeks the parts have finally arrived. Yes, I found a way to plug my rear brake lines and use my car in the mean time. Front brakes do 80%-85% of the braking. Wet or snowing conditions are to be avoided though as fish tailing and a spin is likely.

Now to move the electric motors to the new calipers. Easy as its two bolts, install the pads and calipers, connect brake lines and electric and done..

 

[plain OM]

Good to hear it can be resolved, but with you on the cost!

Have you done the replacement? If not yet, might I suggest taking photos as you go (new calipers, "move motor" etc) and posting to this thread? Thinking of others who might end up in the same situation; referral to this thread would at least provide some solace, and direction.

Let us know when it's all back and up-and-running.

 

[dat2109]

With the wiring connector being so out in the open on the rear calipers it would be pretty simple to just pop off the pigtail and not worry about a friend or assistant touching that button. I'll be certain to do that or something to disable them next time I need to work on electric brakes!

 

[scorch3d]

I'm only posting in this thread as I recently changed my 15 Outback brake pads, knowing the concern about the parking brake. I was told vehemently by a local shop AND the dealer to NOT attempt this out of my garage. There is no user interface for retracting the parking brake fully unless your car is hooked up to a computer with the right maintenance software.

And to that end....my dad said SCREW IT....and we figured it out.

1. With the car off (and battery still attached), we removed the wiring cable from the rear caliper that triggers the parking brake.
2. Remove the caliper and pads. You can use the old pad with the C-clamp mentioned below.
3. This next part is dead serious, not kidding at all.
4. My dad finds a 12V adapter from some old toy car or hair dryer or something and uses a volt meter to confirm it outputs 12 volts (the same as your car battery!).
5. He takes some alligator clips, hooks them to the adapter wires, then to the volt meter prongs (which are hooked to the ac adapter, not the volt meter itself). you need the prongs b/c the parking brake wiring harness plug is very deep and narrow.
6. He continually touches the volt meter prongs to the parking break mechanism where the harness plugs in. If you touch it one way, the polarity compresses the brake, reversing polarity retracts the brake.
7. After several attempts the brake magically retracted completely, only 1-2mm each touch. We used a tightened C-clamp as a precaution for the caliper as it retracted.
8. We change the pads, install the calipers, and reconnect the parking brake to the car's wiring harness.
9. Start the car and continually engage/disengage the electronic brake about 10 times to get it to reinitialize with the new pads...and VOILA! All done. Take it for a test drive.

Been driving now over a month with the new pads, using the parking brake every single day with no issues.

 

[Flightbo]

2015 electronic brake retraction

I can confirm the procedure that scorch3d used with some additional information: I am a 30+ year aircraft electronics tech and can tell you that this sort of procedure will not damage the motor, but you do need to watch what kind of amperage is going in. Please don't hook the battery straight into it.... I used a small, 0.77amp, 12v pencil sharpener power supply. It very slowly moved the piston. I would say about 1/3mm every 2 seconds with the motor sound at the same time. When the terminals hooked up the wrong way, you can see the piston moved if you look VERY closely. BUT when they are hooked up correctly, you cannot see it move, but after 30 or so seconds try, gently, compressing the piston and it should move a bit. Continue this until it is just enough to get the new brake caliper installed. I don't know if this motor has an electrical switch to stop it at the retraction limit, so I would be careful not to do it too much.

Thanks again SCORCH3D!

 

[dima420]

Great Job scorch3d and father

Thanks for additional comment Flightbo

Does anyone know how to: Using the Subaru Select Monitor, go to the brake maintenance mode according to the display screen

 

[AvidHiker]

Just wanted to bump this thread because I see at least 2 people tried this motor trick, as described by scorch3d. A neat idea, but this is NOT necessary, and definitely risky. Refer to the FSM. The SSM is not required to change the rear pads. More discussion here:

https://www.subaruoutback.org/forums/138-gen-5-2015-2019/501775-brakes-diy.html