Upper two pistons not moving in both front calipers

hi! So I’ve recently purchased a 1995 Range Rover classic, now I’ve run into an issue where my brake light is on, as well as my ABS and TC light. And the brakes were very bad. First off I removed both from calipers, put in new pistons and seals, they moved like butter again, but when I reinstalled the calipers, only the upper 2 pistons won’t compress on both calipers. So I take it it’s not in the caliper. And I’m stuck now. What do I check next?
Cheers

Not a clue with your model but on daughters Corsa a few years ago front brakes not working on one side at MOT time , mechanic was trying to bleed but no joy turned out it was the abs unit in engine compartment had seized a bit , I assume it’s what pulsed the brake pressure in the lines when abs reqd.
Hopefully someone answers soon with more specific model experience

Air trapped in the upper part of the caliper?

Datatek said:

Air trapped in the upper part of the caliper?

Click to expand...

All calipers are bled the right way.

Have you checked with pipe disconnected to upper calipers that fluid comes out when you pump peddle , if no fluid then that would be same as Corsa with seized abs unit if yours has one

Do they have a supply and bleed nipple for each piston in the caliper and have you done both

My RRc knowledge only goes up to the 1992MY but I believe that all 1990s classic models had the same ABS system so with your abs system you will find additional bleed screws at the accumulator and and the hydraulic booster, both next to the abs unit the system is bled in a “very strict procedure” with some of it needing the ignition switch IIRC
As always on the RRc the upper bleed screws are first when u come to the front calipers
You definitely need a pressure bleeder to make things simpler with this system and all its bleed screws.
Sorry if you’re aware of all this.

I glad that the abs brake system fitted to my disco is a lot

Datatek said:

Air trapped in the upper part of the caliper?

Click to expand...

Interesting when there is a bleed screw available

According to RAVE the 1995 Classic has two circuits for the front calipers. The correct bleed sequence is complex (like the P38), but not all of it can be done with pressure bleed kit.