Finally something other than procrastination and delaying wet sanding.
Have I ever mentioned that I hate sanding?
Well I finally got annoyed with the brakes after nearly running into the fence for the 47th time, while pumping the brake pedal 15 times and ripping the handbrake on.
Using the highly scientific vice grip on the brake line and stomping on the pedal method, I isolated the issue to the front. Moving aforementioned scientific clamping device from front left to right soft line did not affect pedal travel, so both calipers seemed a touch sad.
RH disc appears alright. Surface rust as to be expected. But the wheel bearings feel alright.
LHS did not fare so well. Significant wheel bearing play, which I believe caused uneven wear on the disc.
It looks less severe in photos.
The pads tell the story.
LH pads to the left, RH pads to the right.
Notice the gap in the LH pads. I suspect in addition to the bearing play, the pads were not sitting correctly in the caliper carrier due to welding on the pad surface of the carrier. Dunno why. But it is noticeable, will affect where the pads sit and require replacement. And also poorly done.
Caliper bores and pistons had a fair bit of gunk, but the pistons were easily removed with a bit of compressed air, so unlikely to have been seized.
Both caliper bores and pistons cleaned up pretty well, so I can reuse them with a new seal kit. Piston and slide pin dust boots are trash. Both calipers have been replaced at some point anyway, and the presumably aftermarket seals have broken down.
So why did the calipers seize?
I suspect a combination of aftermarket slide pins which, on the top pin, do not have a lip for the anti rattle sleeve. And someone had used regular moly grease in the pin bores, I.E petroleum based, not brake grease. Hence why the anti rattle sleeves have expanded and broken down in the bores, causing the pins to seize.
Water ingress may also be a factor, as all the pins and bores had some surface rust.
Anyway, I'll dispose of the junk bits and order a genuine rebuild kit and replace that booger welded carrier.