Auris Rear Brake Piston

[adam_d]

Hi guys, spent most of this morning on this, and can't seem to get anywhere.

My dads Auris 1.6 needed new pads on the rear, so we had a go at changing them this morning. It was all going well til we tried to get the piston back in. We have the rewind tool from Halfords, but we cannot get it to budge inwards at all. Turning clockwise is completely stuck, it just will not move, and it seems to have moved out a little Anti-clockwise has no resistance, but the tool doesn't spin that way, and it doesn't seem to go in either. We have the fluid reservoir cap off, but it just won't budge, so it's currently stuck in the garage with the rear brake apart. Are we missing anything here?

Thanks

[clives]

Sorry to hear this as I had the exact same problem on my 2.0 D4D, within the warranty period. Unfortunately Toyota Customer Services only response was that as I had attempted the job myself they would not offer any help. I was faced with either paying to get it towed to the local dealer, (Toyota Club would not cover the tow as it was viewed as a fault caused by me) and get them to do the work which involved the only solution of replacing the caliper. I decided it was cheaper to get the new caliper and fit it myself. Cost about £150 for a new caliper but you may be able to get one from a breakers yard. Unfortunately once the piston has been "cross threaded" on the original fitting, there is no way, according to Toyota, to repair the piston and screw it back. Not good news I'm afraid.

[Mooly]

I'm no expert at all on this but my first thought is you would have to release the bleed screw on the caliper before !Removed! the piston in... just a thought. Just thinking you might be pushing back against the ABS unit... maybe closed valves somewhere in there.

The reservoir cap isn't an airtight seal anyway, they have an air bleed to allow for fluid level changes due to temperature and pad wear.

[Krait]

Presume you are pushing the piston in while rotating it????

Never heard of a piston having a thread to cross. If it was threaded how would it move when you depress the brake pedal?

Sounds very strange for an answer from Toyota.

Krait

[adam_d]

Thanks for the replies.

clives - That doesn't sound good. :( Really hoping that's not what's happened.

Mooly - Good thinking, will try that next.

Krait - Yeah, the tool I got from Halfords, has a little thing on the end which slots into the slots on the piston, and as you twist, pushes as turns at the same time, using a plate to push against. I haven't explained too well, a picture may be better.

I'll try the suggestion of the bleed screw tomorrow, I hope this isn't going to result in needing a new caliper...

[don21]

The offside caliper retracts anti clockwise. Either requires the anti clock caliper tool or a bit of dexterity.

[adam_d]

The offside caliper retracts anti clockwise. Either requires the anti clock caliper tool or a bit of dexterity.

Discovered this yesterday, went out in the morning and it just went straight in using the adaptor off the end of the clockwise tool, and a bit of trickery. Ah well, good to know it's nothing too serious. :D

Thanks for your replies :)

[Krait]

Well done Adam.

Never give up.

[ellingtj]

Just had a clean up of my SR180 rear nearside caliper and after suffering the same problem as the OP I managed to wind it in anti-clockwise. First I tried clockwise with the reservoir cap off and the piston kept coming out, I then undid the bleed nipple and that seem to make the problem worse, so I found this thread, did the bleed nipple up and used my clockwise tool (Halford/Laser) without the reaction plate. It turned fairly easily now and went back in with some moderate pressure pushing it (wearing gloves made it much more bareable though my palm is feeling it now). I think I may have introduced some air into the system so I'll have a go at bleeding it in a few days.

EDIT.

I've done the drivers side/offside (UK car) and this wound in clockwise. So to recap, nearside to the kerb was anti clockwise and offside to the kerb (driver's) was clockwise.

[ziauris]

On 7/26/2011 at 7:38 PM, ellingtj said:

 

EDIT.

I've done the drivers side/offside (UK car) and this wound in clockwise. So to recap, nearside to the kerb was anti clockwise and offside to the kerb (driver's) was clockwise.

Not according to this video???

 

[Corolla2004]

I've got two suggestions to raise after trying to understand the self adjusting mechanism of Auris & later Prius rear brakes (with parking brakes operating on the discs). These rear calipers have the pistons located on screw threads rather being free to move like the front calipers.

1. As Zed suggests; my research says that the left hand (UK nearside) caliper retracts when turned clockwise & the right hand one retracts when turned anti clockwise

2. But am I right in thinking that self adjustment (i.e. taking up of brake pad wear) only occurs when the parking brake is applied? In other words only the parking brake has a ratcheting effect on the piston. This of course has implications for taking up the slack after replacing the rear pads.

Now the pistons have indents to accept & lock to a pin on the inside brake pad. If my second point is correct, then surely it is vital after brake pad replacement to press on the brake pedal first (thus pushing the pin into the indent) & only then to apply the parking brake (thus taking up the slack). Doing these actions separately might cause the pin to locate on a raised portion of the caliper rather than correctly in an indent?

[ziauris]

Spot what is wrong with this rear brake caliper!

[flash22]

That's a bit rough, was it dragged out of a Pond ? It's only weeping a little 🤐 noting a seal kit,piston and a bore hone wouldn't cure and the caliper bracket needs a date with Mr shot blast cabinet

[ziauris]

1 hour ago, flash22 said:

That's a bit rough, was it dragged out of a Pond ? It's only weeping a little 🤐 noting a seal kit,piston and a bore hone wouldn't cure and the caliper bracket needs a date with Mr shot blast cabinet

The caliper was sticking and has destroyed the pads. The sliders/glides pins are OK, but I don't know if the piston was stuck or handbrake seized. I suspect handbrake as there was usually a "thud" type noise coming from the rear corner of the car when I first drove the car each morning, especially in reverse, but only for a second or two and then seemed to resolve itself.

When I thought about taking the wheel off, I thought at most it'll be the caliper slide/glide pins stuck and I'd just lube them up. But when I opened the caliper I was shocked. 

Not sure how to check if the handbrake cable is the problem or whether it's the handbrake mechanism on the caliper or if it's the piston. I'm watching some youtube vids to help educate myself (unfortunately most of them are from the USA where the corolla has drum brakes :() but I'm planning to open it up again this weekend  and try to fix it. If anyone has had a sticking rear caliper on their Auris and can give me any tips, I would very much appreciate them.

[Konrad C]

13 hours ago, ziauris said:

Spot what is wrong with this rear brake caliper!

Can you take a photo of the face of the piston? There are a couple of reasons which will tell me if it's a wind back type, and the cut outs are at the correct angle in the caliper. The reason is an incorrectly wound back piston, can cause uneven inner brake pad wear like a cut cheese, or the caliper piston skewed at an angle, causing the piston to jam in the bore or let the seal leak. This is because some brake pads have little protrusions on back of the pads and these need to sit within those cut outs. 

Here are photos of a similar brake caliper from a Vauxhall Corsa VXR which the inner brake pad wore down badly. First the incorrectly positioned piston 

 piston cut outs in wrong angle! 

 piston wound back and at correct angle to the caliper. 

Also I have this universal brake piston wind back kit, for left and right handed pistons.  

I recently posted a reply on the Avensis forum on rear brake pad replacement. 

[Konrad C]

14 hours ago, ziauris said:

Spot what is wrong with this rear brake caliper!

That looks like it's not been touched in a long while, or has been sat in water for a while. The inner pad looks to have delamination from the backing plate. The piston looks oily. 

[Corolla2004]

I've just done my rear pads & discs on my 2011 Auris hybrid at 80k miles They were last replaced by a Toyota dealer at 50k miles! The pads were half worn but the discs were not good.

I was expecting to find stuck sliding pins but cause of the problem was stuck pads due to bad rust on the mounting brackets which was squeezing the little insert pads holders tight. After removing the rust with a file i found the pads were free to move easily. So i recommend checking for rust rather than assuming that the replacement pads are too big as others have done.

Also, to my surprise, I found both pistons retracted clockwise. The left hand one (nearside UK) went back easily but the right hand required a lot of pressure. I used the same wind back kit that Konrad has and found the 'F' adaptor fitted perfectly. 

I was delighted to find genuine Toyota rear pads & discs on eBay for a total of £88 from Toyota dealers. The discs were made in the UK & the pads in Japan. For reference the discs were 42431-02190 & the pads were 04466-12150 & my hybrid's model code is ZWE150. However the mail order took several days to arrive.

[flash22]

iirc the disc's are TMD friction aka Pagid, Texar and Mintex

[ziauris]

On 7/30/2020 at 8:28 AM, Konrad C said:

Can you take a photo of the face of the piston? There are a couple of reasons which will tell me if it's a wind back type, and the cut outs are at the correct angle in the caliper. The reason is an incorrectly wound back piston, can cause uneven inner brake pad wear like a cut cheese, or the caliper piston skewed at an angle, causing the piston to jam in the bore or let the seal leak. This is because some brake pads have little protrusions on back of the pads and these need to sit within those cut outs. 

Here are photos of a similar brake caliper from a Vauxhall Corsa VXR which the inner brake pad wore down badly. First the incorrectly positioned piston 

 piston cut outs in wrong angle! 

 piston wound back and at correct angle to the caliper. 

Also I have this universal brake piston wind back kit, for left and right handed pistons.  

I recently posted a reply on the Avensis forum on rear brake pad replacement. 

Hi,

 

I had the rear pads replaced by a local garage and he does taxi cars regularly so hope/doubt he didn't put them in wrong. The Auris rear caliper is a wind back type as it integrates the handbrake mechanism. I am planning on opening the caliper tomorrow to see how bad the damage is and trying to repair it.

 

Has anyone had the handbrake cable seized or the handbrake mechanism on the back of the caliper seized which has caused something like this?? If so how did you fix it.

 

Thanks

 

 

[ziauris]

Fixed it (I think). Just to sum up:

1) Nearside caliper retracts when turned clockwise. I used adapter E in Konrad's pic above. 

2) Found out that the pads were seized in due to debris/rust and this was caused all the issue. Had to hammer them out. Best to have some new shims as mine broke apart due to rust.

3) Konrad, I took some pics but forgot to check if the piston "holes" line up with the "tabs" on the back of the brake pads (Doh!). But I did retract the piston ALL the way in so it should (?) be in the right position. 

4) Anyway, brake seems to work fine at the moment. Happy that I didn't have to buy a new caliper as this one looked beyond repair from the photos but I spent quite a bit of time cleaning it up and hope it will keep on working.

Any questions, please let me know.

 

[Corolla2004]

Glad you were able to resolve your problem. As my Auris also had seized rear pads due to rust; it might be wise for other Auris owners to check for this at the same time as checking for seized sliding pins.

As you're not certain that your pistons are properly aligned with your pads; I would recommend doing the check I did which is to see that the rear tyre rotates freely when jacked up & with the handbrake off. Alternatively after a gentle drive put your hand against the caliper/wheel to check its not hot due to the pads rubbing.

[ziauris]

On 7/30/2020 at 8:28 AM, Konrad C said:

Can you take a photo of the face of the piston? There are a couple of reasons which will tell me if it's a wind back type, and the cut outs are at the correct angle in the caliper. The reason is an incorrectly wound back piston, can cause uneven inner brake pad wear like a cut cheese, or the caliper piston skewed at an angle, causing the piston to jam in the bore or let the seal leak. This is because some brake pads have little protrusions on back of the pads and these need to sit within those cut outs. 

Here are photos of a similar brake caliper from a Vauxhall Corsa VXR which the inner brake pad wore down badly. First the incorrectly positioned piston 

 piston cut outs in wrong angle! 

 piston wound back and at correct angle to the caliper. 

Also I have this universal brake piston wind back kit, for left and right handed pistons.  

I recently posted a reply on the Avensis forum on rear brake pad replacement. 

I have a pic that seems to show what you stated , that the pads were not aligned to the caliper cut outs and I think this caused all the problem. the guy that replaced them does a lot of taxis etc so should know what he is doing but i guess he is one of those that does the job rather than doing it properly. now that i have the equipment and knowledge i will never let anyone else touch my brakes. it is an easy job and i encourage others to DIY it.

[Konrad C]

3 hours ago, ziauris said:

I have a pic that seems to show what you stated , that the pads were not aligned to the caliper cut outs and I think this caused all the problem. the guy that replaced them does a lot of taxis etc so should know what he is doing but i guess he is one of those that does the job rather than doing it properly. now that i have the equipment and knowledge i will never let anyone else touch my brakes. it is an easy job and i encourage others to DIY it.

A lot of people (including myself) was never aware, especially some mechanics! I only realised when I inspected the brakes, due to the wear indicator touching the disc. The inner pads on both left and right wheels, had worn down at an angle, due to the piston not properly aligned. The outer pads were practical at full thickness! 
If you have to put your trust in the mechanic, if you cannot change the pads yourself.
Anyway glad you sorted the brakes. 
 

[ziauris]

I've done the driver side (offside) rear pads and the brake caliper had to be turned anticlockwise. Don't get this at all. Was watching a audodoc video and that showed albeit a EU car and what would be the offside here was clockwise. Someone above reported both theirs as clockwise!!

 

Oh and the rear disks have done around 100k and still 9mm left!!

[TonyHSD]

37 minutes ago, ziauris said:

I've done the driver side (offside) rear pads and the brake caliper had to be turned anticlockwise. Don't get this at all. Was watching a audodoc video and that showed albeit a EU car and what would be the offside here was clockwise. Someone above reported both theirs as clockwise!!

 

Oh and the rear disks have done around 100k and still 9mm left!!

I can confirm on hybrids both sides are clockwise but I believe it’s a totally different brake system and different callipers.