Facelift Brake piston leaking.

T-1000

Well-Known Member
Gold Supporter
Changed the discs / pads today.

All good until doing the rears when I got to the final rear caliper I noticed the dust seal was damp, so I removed it from its outer seating position and sure enough it was full of fluid.
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Luckily I had a seal kit I bought a few months back.
Clamped off the line and unbolted it.
Then set about removing the piston so I could access the inner main seal.
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Fitted a new flat seal and re-assembled carefully pushing back in the piston using a wind back tool.
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Checked the passenger side caliper and that was pretty much dry inside.


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T-1000

Well-Known Member
Gold Supporter
Update

The DBA pads have been on for 500 miles now

They aren't a pad i think i'm going to get on with I'm afraid, initial bite is poor, pedal travel feels quite long with these before anything happens.

They don't inspire confidence in knocking off speed, especially going into a fast bend, the Ferodo DS2500 pads are leagues better then these.

I'll give them a little while longer, just in case they need more time to fully bed in.

One thing I will say they are quiet...........and that's about the limit of the good news.
 

T-1000

Well-Known Member
Gold Supporter
Good feedback T thanks ,my (F) performance been on now over couple months and well happy with them

They’ll be coming off if there’s no improvement soon.


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T-1000

Well-Known Member
Gold Supporter
What happens when a piston is fitted incorrectly over the centre winder…….

If you ever remove the rear caliper piston to change a seal, make sure it’s in exactly the right position when you fit it back in.

It can get jammed and this can cause 1) the piston doesn’t retract fully so it causes a squeak as the wheel is turning when off the pedal.
2) when it gets jammed it winds out too far and you get this happening.
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So a rebuild is required in which you wind the thread back out until you see the line of ball bearings, then drop the ball bearings that have come out one by one with tweezers back in, winding the thread back up to trap them in the groove.
They are trapped in the grooves / thread by a long tension spring.
Which can be seen below

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I actually sourced a new piston from an ATE parts supplier because I thought there was an issue with the OEM one.
Turns out the OEM has a different internal machining at its base.
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Verses the none Audi / ATE 42mm piston I bought
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Here’s a video comparing the 2 pistons and what can happen

OEM ATE

Aftermarket ATE


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Last edited:

T-1000

Well-Known Member
Gold Supporter
Update

The DBA pads have been on for 500 miles now

They aren't a pad i think i'm going to get on with I'm afraid, initial bite is poor, pedal travel feels quite long with these before anything happens.

They don't inspire confidence in knocking off speed, especially going into a fast bend, the Ferodo DS2500 pads are leagues better then these.

I'll give them a little while longer, just in case they need more time to fully bed in.

One thing I will say they are quiet...........and that's about the limit of the good news.

Another Update

DBA pads have significantly changed characteristics after 1k of use.

Miles better bite / stopping power and the braking confidence they give now is soooo much better.
Pedal feel is also back to what it was with the Ferodo pads.
Quite impressed now these are fully bedded.


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