Brake pad retaining springs - about to go insane...

Craignaneun · July 20, 2020

Hi,

Hoping someone can help me as I'm going nuts here....

I have a 2010 IS220d F-Sport. Only had it 3 months and found the rear calipers were seized so this evening started to fit new pads and discs and new slider pins/seals. All went to plan until I'm reassembling the pads and in particular the retaining springs. I'm attaching a few photos of before I disassembled but the spring(s) that stop the pins moving are baffling me.

They pass through the same holes as the main pins - worth saying also that the pins are fitted from the inside facing out. Now when I look on various videos online these springs are completely different and the retaining pins are fitted from the outside facing in. The wheels are 18" and the calipers are stamped R18 (if that makes any difference).

So, I'm wondering first: are these springs correct - they just don't seem right. I've tried to refit them but they're impossible. Worth also saying that they are fitted slightly differently on either side.

Anyway, three pictures attached and hoping someone can help me here.

Cheers, Scott

Mihanicos · July 21, 2020

The spring in question its ends go into the pins behind the pad so as the pads wear, they move away from the spring ends fitted in the holes of the pins. The centre part of the spring goes into the brake pad.

First fit the ends of the spring into the pins, then turn the centre of the pin and drive it into the centre hole of the pad.

Make sure that as the pads wear, they move away from the spring thus not inhibiting their movement towards the rotor.

Chris.

Edited July 21, 2020 by Mihanicos
Forgot to sign.

Craignaneun · July 21, 2020

Thanks Chris,

So, if I understand correctly, the springs I have are correct and they do pass through the same hole in the pad as the pins.

But....the pins have been installed the wrong way round? The reason I say that is that it wouldn't be possible to drive them into the pad after installing the way they are now, i.e. fitted from the rear facing out.

Thanks, Scott

Mihanicos · July 21, 2020

The pins themselves have small holes through which the spring end goes through. Rotate the pin until the hole is visible, it is about the same diameter as the spring. The spring in question has to be facing the opposite side so the pads as they wear, move away from the pin holes so the spring does not prevent them from moving towards the rotor. The thin end of the pin, fit the spring so that the pin cannot come out of the caliper the same principle as described above. This spring prevents the pin from sliding out of the caliper.

Chris.

Mihanicos · July 21, 2020

I attach the diagram from lexus repair manual. My rear brakes are like yours. Sorry for the confusion about a second spring. hope this will help you.

Chris.

Scan0004.pdf

Mihanicos · July 21, 2020

Another attempt to upload the file.

Chris.

Scan0004.pdf

Craignaneun · July 24, 2020

Chris,

Thanks for the diagram. I'm coming to the conclusion that the arrangement I have is completely wrong for a number of reasons. Firstly the springs do exactly the opposite of what you've said, i.e. they stop the pad moving towards the rotor. Also, the springs I have are completely different to those shown on the diagram you kindly provided. And lastly I can't find anything similar for sale. All kits/springs are as per this eBay listing: https://bit.ly/2ZVGZoz which shows springs similar to your diagram and not what I have (wish I'd taken a picture of the springs).

Anyway I tried refitting but one of the springs broke and frankly the other is not doing anything. So I'm planning to buy the above kit and install and see how it goes.

Cheers, Scott

Mihanicos · July 24, 2020

You are welcome.

Beamish · July 24, 2020

Hi Scott,

This should help.

Main pins are fitted from the outside in.

INSTALL REAR DISC BRAKE PAD

(a)	Insert the 2 rear disc brake pads to the rear disc brake cylinder assembly.
(b)	Install the pad guide pin (upper) to the rear disc brake cylinder assembly.

(c)	Insert the end of the anti-squeal spring to the inner rear disc brake pad.

(d)	Holding the anti-squeal spring, install the pad guide pin (lower) to the rear disc brake cylinder assembly.
(e)	Engage the pin hold clip to the holes of both pad guide pins, and insert the pin hold clip to the rear disc brake pad as shown in the illustration.

NOTICE:
Make sure that the claw of the pin hold clip is engaged to the rear disc brake pad hole.

(f)	Insert the end of the anti-squeal spring to the outer rear disc brake pad hole.

Beamish · July 27, 2020

Apologies Scott, the original illustrations which I attached seem to have gone AWOL.

Looking at your photos above your main problem is that the main guide pins have been incorrectly fitted from the inside out and as a consequence the pin retaining spring is fitted to the inner brake pad when it should be fitted to the static outer pad.

Hope you can make some sense of this.

Dec.