Rear piston notch depth

[Mr Squashie]

Does anyone know the depth of the notches on the pistons in the rear calipers? Specifically genuine Renault ones.

I fitted new rear calipers and made sure the notches were lined up with the locating tabs on the rear pads, but didn't notice that they weren't actually sitting flat against the pad. As a result my rear discs are now in need of replacement as they have badly corroded where the pad hasn't been making proper contact.

Upon measuring the notches it appears they are 1.79mm deep, yet the tab on the genuine pads is 2.33mm tall.

Is this normal?

 

[JamesBryan]

Not sure on the depth, but 1.79mm doesn't sound enough

Have you got a picture of the pistons?

Other option is to grind the tabs down a bit.

 

[Mr Squashie]

Not sure on the depth, but 1.79mm doesn't sound enough

Have you got a picture of the pistons?

Other option is to grind the tabs down a bit.

The tabs on the new pads have been ground down to 1.5mm and they fit perfectly now, just struck me as odd that that would be necessary with standard parts, assuming the replacement calipers are within OEM specifications

 

[JamesBryan]

View attachment 1629566
The tabs on the new pads have been ground down to 1.5mm and they fit perfectly now, just struck me as odd that that would be necessary with standard parts, assuming the replacement calipers are within OEM specifications

Odd that as it does look like it's enough.

Similar depth to this at least

 

[Mr Squashie]

I suppose it's only 1-1.5mm, but then again it's a nearly 100% increase in depth, depending how you look at it. Certainly not something that jumped out at me when I inspected them prior to fitting