Bit of a newbie question here (or two).

The first is why do the rears have adjusters in? I assume it's for the handbrake as normally calipers are quite happy to find their own clearances (like the fronts do).

So then why have adjusters on the inner and outer?

And then what happens as the rear pads wear?

Thanks!
Graham

Yes, it's for the handbrake. This is a great reference for how to adjust from Eric at PMB: http://www.914world.com/bbs2/index.php?showtopic=90625

At the intro he gives a little background on how this works and why. And re-reading it I see he mentions adjusting them "a couple of times a year" I wonder the last time I did mine... Could be why I need to pull the handbrake up a notch or two further now when I park in my driveway.

Also, if the inner adjuster cover hex head is worn out PMB sells an excellent replacement with a slightly large hex size which allows for a solid grip when tightening/loosening

If the covers don't want to come out, remove the entire caliper and use a chisel to turn the cover

The adjusters under the covers float; that is they may pull out after you adjust them. If one is missing, use the adjuster from the other rear wheel. If both are missing, put an ad in the classifids...

I've always liked adjusting the rear venting clearance; it always seems to be a 1 hour task that can evolve into an all day fiasco....

Thanks, I had read that to work out how to adjust mine. But I didn't read it well enough! The bit I missed is that the inner side adjustment 'bolt' is what the HB lever acts on to apply the handbrake. The outer adjuster provides the firm 'stop' so when in inner piston is moved by the HB, the inner pad puts pressure on the disk which must then flex to put pressure onto the outer pad, then piston, then the adjuster and then the caliper.

So if you don't adjust the inner, all that happens is you need to pull the HB on further.

If you don't adjust the outer, then the disk has to flex further.

Another question then. When the brakes are applied and the pistons move under the pressure of the fluid, is the piston moving against that spring (IYSWIM)?

ETA: I mean the spring that can be seen within the piston.

Graham

Thanks for the info on the adjuster covers. I had a little bit of fun with those! The car is new to me (shipped from the US to the UK) and the rear calipers are quite shiny.

I got my 4mm allen key out to try and get them off, was gentle but still failed. Decided to bite the bullet, got the calipers off and the penny dropped...they are PMB refurbed with the new covers on. Got my 5mm allen key out and off they came!!

Graham

Lucky you !