circlips over snaprings? or...

You always want to use new circlips.

 

There's more than that, a lot more. The pistons using circlips have grooves cut circular, snapring grooves MUST be square cut and they are absolutely depth specific as well, using a snap ring in a circlip groove should have it jump out in minutes if not seconds!!!

The angle on the end of pin makes the pin apply force outwards radially as it impacts the circlip, making it lock tighter. The round piston groove makes it do it even more.

Depending on which way you install the snap ring (there is a right way as well as a wrong way) the curved piston groove can make it spring out almost instantly, and ring flipped around will not be fully down in place thus coming out just as easy.

Do NOT swap one method for the other--you WILL be regretting it.

I've reused circlips more than once but they MUST still be circular and not bent, if not they come right out. new ones are so cheap it's silly not to use them.