Rear caliper piston

[Call the midlife!]

Have you cracked the bleed nipple a touch? Might be too much pressure behind the piston?

[Gaz mr-s]

Bleed nipples loosened....a little fluid out. Just started the other side & rain on hard.

[Gaz mr-s]

I turned back the piston on the nearside...still turning but I gave up. The piston still sits proud of the rubber seal, not what I've seen with other calipers. The clearance for disc & pads is approx 46mm.  Disc + pads measure 44mm. 

The offside with the problem caliper measures less than 42mm.

Simon Sinclair is going to reply tomorrow.

[Call the midlife!]

Another thought, have you disconnected the handbrake cable at the calipers? Might be the inner mech not letting it go back far enough?

[Gaz mr-s]

Another thought, have you disconnected the handbrake cable at the calipers? Might be the inner mech not letting it go back far enough?

Yes

[Call the midlife!]

It's an odd one alright, particularly as you're just refitting something that was previously working fine.
Be interesting if there's a fundamental problem as I've got a pair of brand new ones from Simon waiting to go on but I've not heard of any other issues with his kit.

[Call the midlife!]

The manual suggests checking the discs for runout and advancing them a quarter turn each time until they're within spec, always the potential the disc isn't seated in the optimum position I suppose?

[Joesson]

I turned back the piston on the nearside...still turning but I gave up. The piston still sits proud of the rubber seal, not what I've seen with other calipers. The clearance for disc & pads is approx 46mm.  Disc + pads measure 44mm. 

The offside with the problem caliper measures less than 42mm.

Simon Sinclair is going to reply tomorrow.

That does not "add up", frustrating for you to say the least. Remote diagnosis is always tricky but the measurements indicate that something is amiss.
Maybe the piston is too long, because it was supplied in a box from the factory doesn't always mean it's the right part.
Ask me how I know!

[Gaz mr-s]

Just had a look in the Toyota factory manual - that is quite "agricultural" and suggests pushing the piston in with the handle of a hammer.

.....only the best from our main dealers!

I had another go at turning the problem one, & it did!  Me hearing a clunk as if it was coming to a stop yesterday must have been a red-herring...the other side still turns with 46mm disc/pad gap. Are they not supposed-to come to a stop though, then turn them in to align? I twisted two or three times yesterday & heard clunks...don't know why now.

So thinking back to Paul's post yesterday I got a wooden shaft & gave it a couple of modest hits with a wooden mallet & the damn thing moved in easily....much lighter work than all the turning!

Makes me wonder what the turning is for.  Anyone got an exploded diagram showing the caliper innards?

[Joesson]

As said, remote diagnosis is difficult, but there has been a theme here and now you've  hit on it.

[paulj]

So thinking back to Paul's post yesterday I got a wooden shaft & gave it a couple of modest hits with a wooden mallet & the damn thing moved in easily....much lighter work than all the turning!

I didnt expect my post to be the useful one - perhaps they main dealers do know the right way after all!

[Ardent]

Just had a look in the Toyota factory manual - that is quite "agricultural" and suggests pushing the piston in with the handle of a hammer.

.....only the best from our main dealers!

I had another go at turning the problem one, & it did!  Me hearing a clunk as if it was coming to a stop yesterday must have been a red-herring...the other side still turns with 46mm disc/pad gap. Are they not supposed-to come to a stop though, then turn them in to align? I twisted two or three times yesterday & heard clunks...don't know why now.

So thinking back to Paul's post yesterday I got a wooden shaft & gave it a couple of modest hits with a wooden mallet & the damn thing moved in easily....much lighter work than all the turning!

Makes me wonder what the turning is for.  Anyone got an exploded diagram showing the caliper innards?

I'll pm you a link that might be useful.

[Gaz mr-s]

I didnt expect my post to be the useful one - perhaps they main dealers do know the right way after all!