D2 5U coper ring around the liner???

Hi!

I am working on a 5U. It was stuck becouse water sitting on 2 of the pistons.
Now i pull the liners and around the liners there is normaly the thin coper ring.
On this one there is a second coper ring/band see the picture. it is on all 4.

Any idea what tis is? why it is there?
New liners going in do i than put them back in place or forget them?

(Orginal it was as on photo 6 )

Thanks Niels [attachment=25691]20141021_202714_resized_1.jpg[/attachment][attachment=25692]20141021_202655_resized_1.jpg[/attachment][attachment=25693]20141021_202648_resized_1.jpg[/attachment][attachment=25694]20141021_202640_resized_1.jpg[/attachment][attachment=25695]20141021_202636_resized_1.jpg[/attachment][attachment=25696]20141021_202546_resized_1.jpg[/attachment]

I haven't seen that arrangement before. Do your replacement liners fill the bore? Still need to wind up with 0.002 to 0.005 inch liner projection with the liners pressed down to properly seal.

Hi Team,
the shields/sleeves-- are to inhibit heat flow from the working area of the liner to help the area run hotter and so stop sulphuric acids forming and corroding the components.
Scans below--only ones I can find amongst my incomplete collection-- cover this in greater depth.
Hope the helps.
Cheers,
Eddie B.

Better save those copper sleeves, they belong in a museum.

Thank you for the info!
Looks like this isn't use a lot in the d2.
That explains the serial number 5u9126 SPG
It was fit at factory