Seizing Caliper Piston?most Likely But Can I Fix It?. Rear Piston Shap

[waqar_lionheart]

Hello fellow toyota owners,

Just a quick query, I changed my brake pads on thursday after a shocking brake. I had not driven the car in a long while but wife used it on almost daily basis. I decided to change the brake pads as a matter of urgency. So i did that and found that 3 out of 4 of the front sets were more than a quarter left where as driver side inside pad was quite literally showing bare metal. I immediately knew that the piston is causing an issue :(. Any chance i could may be exercise this piston and fix it.

Secondly, I havent changed the rear pads yet as I know (google) that its a wind back piston and i dont have the tools for it. I googled again to try and ascertain the shape of rewind apparatus and the shape of rewind grooves but most results showed a flat surface with two holes and the tool was a round with two sticky out bits (i imagine that ll go into the holes and then help rewind). BUT Interesting thing is that somebody said that Just use some nose pliers to rewind which makes sense. BUT ALL THIS ONLY HELPS if i knew the shape of it.anyone with some help on this please.

Regards,

Waqar

[gazza1286]

The brakes International website has an online schematic for all brakes. The shape of the piston will be there.

Pistons for the front commonly stick when at the limit of their range when pads are nearly worn. You'll probably find that once the new pads are fitted it will be fine. However before pushing the pistons back in it would be wise to peel back the rubber boot and clean up the exposed piston. You could push back and pump back out against the old pads a couple of times if you want if they appear clogged.

[avensisd4d786]

Hello,

There are a few re- wind tools out there.

I have this one

http://www.ebay.co.uk/itm/BRAKE-CALIPER-PISTON-REWIND-WIND-BACK-TOOL-KIT-22-PIECES-car-service-tool-/181439011424?pt=UK_Hand_Tools_Equipment&hash=item2a3e9b9a60

Do these pictures on this listing help.

http://www.ebay.co.uk/itm/Toyota-Avensis-Driver-Rear-Brake-Caliper-Avensis-1-8-2-0-OSR-Caliper-2000-2002-/220905655133?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item336f00cb5d

[alan333]

More likely that the sliders are seized thus pushing only one pad against the disc, rather than "floating" such that both pads push. Make sure you free the sliders off while fitting the new pads.

[waqar_lionheart]

cheers alan333. I shall take it off again and exercise the sliders and grease them too.

Many Thanks.

Regards,

Waqar

[Druid Boy]

Given the age of the car it is reasonable to expect a build up of corrosion in the piston bore. You can pump the piston all the way out then clamp the flexihose to reduce fluid loss, remove the caliper from the car and set about cleaning all of the corrosion off the bore and piston (you will need to get it all off) and then refit the seals and dust covers etc and piston. Generally the exisiting seals are fine for re-use even though loads of people will tell you to replace them. If they aren't damaged or out of shape they will still do the job. You will need rubber/red grease to apply to the seals etc when reassembling the calipers (protects the rubber and helps to prevent future corrosion). New brake fluid is a good thing - you will probably renew it just by topping it up whilst bleeding it through thoroughly. And if you do one side you should do the other as well to balance the performance up. Calipers are not overly complicated but we are generally cautious of opening them up. The other option is to buy a new caliper. Garages replace calipers because it is not cost effective for them to overhaul them. It is cost effective for us to do at home though.

[waqar_lionheart]

Cheers Druid boy I shall take that advice.

many thanks,

waqar

[Konrad C]

Waqar

I have dismantled and fully understand the rear disc brakes of your car. I also have the piston tool if it is needed.

All the other replies are correct so cannot add anything extra.

Konrad

[waqar_lionheart]

I am off to buying new rear pads :). These should be picked up tomorrow.

Regards,

Waqar