Rear Brake pad change.

[Foxcub]

Hi There,

Come to change rear brake pads and have had trouble retracting the cylinder. Clamped off flexy brake pipe and run a bleed off pipe from the bleed nipple to allow for fluid displacement but the piston won't retract. I can do the clockwise turn but cannot get it to retract. I am not sure if a G-clamp can be used to jack it straight back or whether it needs the clockwise rotation at the same time as pushing?

any suggestions?

Cheers :Blush2:

[Foxcub]

Looks like I need to get the piston retraction tool to wind the piston back at the same time as rotating.

Does anyone know how much the VW tool is??

[Col]

you can get them for about £15 from Halfords or motor factors.

[Foxcub]

Thanks for the info BigCol.

Cheers

[*les*]

Hi, i had the same prob just a couple of weeks back. The pistons need turning clockwise and being pressed in at the same time. I found a peice of steel that bridged the gap, drilled and tapped it for an 8mm bolt and used a small pair of mole grips to turn the piston whilst winding the bolt onto the piston. Felt like I needed a third hand to start with but it was very satisfying when it all came together. Hope this helps.

:beerchug:

[Stevef.]

Hi ,
The proper tool like bigcol says make an easy job of it, even if their a bit seized.:)

[*les*]

oops, should've mentioned to not clamp the hose, leave the bleed nipple tight and take the cap off the brake fluid. Put some rag around it to catch any possible overflow, bearing in mind not to contaminate the fluid

[Foxcub]

Thanks for all the info, much appreciated.

Bought the wind back tool from Halfords in the end and it made the job very easy.

Before I got the tool (when I encountered the wind back probs) I had used the method of opening up the bleed nipple and clamping the hose (as described in the Haynes Manual) which was a bit messy.

When using the wind back tool I left the bleed nipple tight and let the fluid rise in the resevoir. Once the pads were change I bled each caliper as I went along as I was changing the fluid as well. Self bleed kit worked a treat also!

Took about 20 mins (including cleaning ) where I was changing the pads and bleeding at the rear and about 10 mins per side at the front just to bleed.

Note: - Worth putting a bit of copper slip in the wheel hubs if you have got alloys to prevent them seizing.

Not sure how much VW would have charged for changing the rear pads and replacing the brake fluid but costs were as follows:-

31 Rear Brake Pads (from main dealers)
20 Wind Back tool
10 Brake Fluid

Total 61 ( sorry can't use pound sign as yet as I need to set up the keyboard language).

It would be interesting to know what the main dealers would charge to compare costs.

Thanks once again for all your assistance

Cheers:beerchug:

[snapdragon]

Great stuff! What was this tool like from Halfords? Is it like a fancy G clamp that turns the caliper while you twist?

[Col]

The tool is basically a glorified g-clamp but a few things to remember;

1, The thread / pitch angle of the thread matches that inside the caliper, if you use alternative methods you could be rotating the piston out of sync therefore risking damage to the caliper.

2, On the face / driving plate there are two dimples which engauge in the recesses in caliper piston which provides a positive bearing and prevents one rotating without the other.

3, There is also a thrust plate which bears onto the business side of the caliper rather than the probably weaker back of the caliper which you would use if you used a g-clamp.


I've recently changed my 4th set of rear VW pads (3 on my Golf and 1 so far on the Passat) and must say I don't know how you could do the job without the tool. I got mine from GSF and it has a reversible plate for larger pistons as well which coincifdently is perfect for using on the fronts, does the Halfords one have the same facility?

[Foxcub]

Attached are a couple of images (hope they load?) of the tool, you can reverse the driver plate for different size pistons but the thrust plate is the same either way around.

[Col]

Yep, thats exactly the same as the one I got from GSF.

Brilliant piece of kit.

[jwiens]

I have a 2002 passat v6 4motion.

After doing the rear brakes (which was a pain) I bled them the traditional style at the caliper. When I was at the reservoir for the brake fluid, I noticed a little adapter that looks like you could remove the air from the brakes at the reservoir.

Anyone have experience doing it this way?

Jordan

[*les*]

Hi Jordan, First off I have to say how jealous I am that you have a v6 and I only have a 2L sport. More importantly, and without going outside to lift the bonnet to check, I have never come across a method of bleeding the brakes at the reservoir on any car, let alone the passat. And if it were possible to bleed the brakes at the reservoir, why would anyone go to the trouble of getting all grubby and doing it wheel by wheel? ... Jordan you must understand it's Saturday night, i'm full (nearly) of Stella and you're really scaring me with your Little Adapter for brake bleeding. You must now explain yourself or i'll never sleep again.

[jwiens]

MMMMMM ... Stella.

I think next time I do the rear brakes I will make sure to load up so as to make it a remotely pleasant experience. :beerchug:

The reason I asked about alternate methods is because I know people have invented "power bleeders" that hook up to the cap of the fluid reservoir and essentially suck all the air out of the brake lines. It is brilliant, expensive, and fairly easy. But when I looked at the VW reservoir, I noticed the little yellow cap to the left of the main cap and when I took it off I noticed two small nipples that looked like a tool attached.

Curiosity got the best of me.
:)
jrw:biglaugh:

[Col]

I've never had the pleasure or even mis-pleasure of bleeding my brakes but do know that the master cyclinder is bleedable separately to the rest of the system.

...It could be that.

[darkstar]

thanks to all for good advice changed rear A4 pads very easily after making a simple tool out of a butchered old clamp and steel bar worked a treat would not have sussed the fact they needed rotating at the same time ..cheers

[bigshineybike]

Thanks everyone.
I joined the forum today to find out how to do this job.
pre-internet I am sure I would have kept on tightening up the "g" clamp till something gave!

I read all the threads and then went back out to the car. Using a gentle tweak on a G clamp between clockwise twists on the piston with a pair of water pump pliers got both pistons back into the cylinders.
Jobs done.
My note since I wondered but now have done it;
simply twisting the piston doesn't work, there is something happening inside the cylinder that needs to be pressed to make the piston go back in. if you press too hard on the piston with the clamp the piston will not turn. ( i hope that makes sense)

[thebaldeagle]

im just sooo grateful my good friend works at our local ATS ....i had front discs and pads and rear discs and pads changed without even getting my hands dirty lol....all for a crate of the afor mentioned stella lol


all done for less than 100quid

[darkstar]

come on Bald eagle all mine where done for £37 so i bought myself loads of Stella with the change !!

[mluton]

This guide will help a few people, used this on my vRS.
http://www.passatworld.com/forums/showthread.php?t=179518