[larryc]

Raybestos DPS85170 Rear Caliper Pistons are still available but they do not have the self adjuster assembly. anyone have exp transferring the org. to a new piston? there is a serrated ring-possibly a circlip under it that appears to hold parts in place but it will not budge.see pics.the oem ford piston #  E25Y2B588A is obsolete.new piston;

[TurboRay]

.
The whole caliper isn't available? I don't see any gaps in that so-called "serrated ring" that you're referring to as a potential "circlip". I suspect that it MAY be a threaded retainer, requiring a special tool for disassembly. PLUS.......if the second pic is your new replacement, there isn't any groove or female threads in the bore for either strategy. Have you looked on You Tube for disassembly destructions?  <shrug>

[larryc]

8 small insets on the outer diameter ring then beneath it appears to be a circlip but maybe not as there is no groove on the new piston.emailed raybestos as there must be a method if others are buying the bare pistons.zero videos on the tube.zero calipers available but rebuild seal + O ring kits are still available when they come up on ebay." NOS 1975 - 1977 FORD MAVERICK GRANADA REAR DISC BRAKE SEAL KIT D5DZ-2B595-A NEW".https://www.ebay.com/itm/391702493953

[TurboRay]

.
LINK  (both sides are available)  <shrug> 

[larryc]

thanks but note no sliding pin mounting.could have been a scorce for a self adjuster & piston but according to partsgeek.com they don't interchange either.

[TurboRay]

.
You didn't say anything about "sliding-pin mounting" in any of your posts.......only that the application was a 75-77 Granada &/or Maverick, so that's what I looked up on Amazon. OTOH, the exploded view you posted above DOES show a pair of threaded "caliper location pins".  

The caliper I linked is claimed to fit a 77 Granada with front & rear "non-ABS" disc brakes. If not correct ~ perhaps you could be more specific about the exact car you're working on.......year, make & model? 

BTW ~ Why are you replacing the piston(s)? Is it corroded? The bore in the cast-iron housing usually gets pitted before the piston. That's why most savvy mechanics usually replace the entire caliper assembly as a unit ~ since the rebuilt ones often have new pistons and SOMETIMES new pressed-in stainless bore liners. <shrug>

[larryc]

working on a '86 SVO,org. calipers were replaced 25 years past when doing a mechanical resto..spares that have been sitting all that time.the replacement calipers lasted 25 years,30k miles and needed a rebuild-frozen piston but was reusable.diagram is from M. Flemings write up on how to rebuild the SVO rear caliper.https://www.svocop.com/Articles/2/index.html  think the local Upull or the Fox Fest this year maybe the best chance of finding a spare Lincoln mark 7 for parts as they use the same rear caliper.thanks for your input.

[TurboRay]

.
BOTH of the rear calipers (L & R) linked HERE are claimed to be for your 86 SVO (complete with "sliding pin mounting").  <shrug>

[larryc]

Thanks.when adding into cart they come up no longer available.

[TurboRay]

Thanks.[ BUT, ]when adding into cart they come up no longer available.

Well........they're "out there" somewhere, Larry.  I've already spent way too much of my time searching and I'm sure that your Google/Bing/eBay/Amazon/Rockauto search skillz are as good as mine. Sooooo..........rots of ruck!!  <thumbup>