Technical Can't get rear calipers off! Help!

[JTDLee]

Hi chaps.

Got a 2005 1.9 JTD115 dynamic.

Wanted to change Rear pads, but can't get the caliper to slide off the disc because the discs are too worn and the pads won't go over the unworn outer shoulder. Because the pistons won't push back the 6mm or so (the unworn disc edge sticks out about 3mm on each side of disc from the worn surface), I can't see how to do the job. I can't get the caliper off the disc to get at it to retract the piston to fit the pads.

I can't get at the disc to angle grind the raised edge off on either side because of the shroud that goes around behind the disc. Does anyone know how to get this shroud off? Looks like it's bolted on with the 4 main bolts holding the stub axle on.

Any help much appreciated. And yes, I know how to retract the pistons once I get the caliper to slide off the disc. Need to get these damn shrouds off....:bang:

 

[Deckchair5]

Difficult to imagine what your problem is as the pads stay on the disc and the caliper is slid out like this but if you've somehow got a clearance problem and need to retract the pistons then (in theory because I've not done this) you may be able to retract them by reversing the mechanism that pushed them forward

First off
Make sure you give yourself as much slack in the system as you can get by

slackening off the handbrake cable in the cabin behind the handbrake lever

and detach the handbrake cable , clamping the brake hose and undo the brake bleed nipple so you give an easy escape route for fluid

Ok now if you understand how the ratchet mechanism works then you can see what you can try.

piston adjusting mechanism thread bolt

Inside of piston
The caliper piston has an internal thread and the handbrake lever on the caliper ratchets this screwthread in to take up slack everytime you use the handbrake

So, if you can detach the lever spring, then you might be able to rotate the screw and retract the piston from the rear enough

The photos are a Budwig caliper, not Stilo, but they'll be very similar

 

[sixpotman]

Don't the pistons have to rotate as you push them
back.

Do a search for changing rear pads. Few posts explain it.

https://www.fiatforum.com/stilo/85765-rear-brake-caliper-wind-back-tool.html

John

 

[Deckchair5]

Don't the pistons have to rotate as you push them
back.
Once you have access to them yes.
But that's Lee's problem, he can't gain access with the pads on top of the pistons

 

[Muppet1]

Have you managed to get them off yet and sort your pads out.

 

[john55]

But that's Lee's problem, he can't gain access with the pads on top of the pistons

Bash it off using a copper head hammer, or if it still wont come off, grind the lip off the disk with an angle grinder. If your disks have that much of a lip, they need replacing anyway.

 

[JTDLee]

View attachment 62983
Difficult to imagine what your problem is as the pads stay on the disc and the caliper is slid out like this but if you've somehow got a clearance problem and need to retract the pistons then (in theory because I've not done this) you may be able to retract them by reversing the mechanism that pushed them forward

Deckchair5, you are a real help. That diagram showing the caliper in 2 bits helped me no end. Still think the windback system is like trying to reinvent the wheel by adding little corners. Bloody Bosch.

Anyway, I got the job done, new pads and discs. For the Nearside rear, I wound the caliper in with a large-ish G-clamp with the screw side up against the piston. By then grasping the edge of it with plumbers grips, the piston is turned anti-clockwise a bit, then the clamp done up a bit in this sequence until the piston is pushed fully back. Takes about 5 mins.

For the Offside rear, the clamp is applied in the same fashion, but no grips are needed. Because the clamp's screw is turning clockwise, it both pushes and turns the piston simultaneously, all you have to do is turn the clamp. 1 min and piston is back. Ignore what others say about needing a special tool, it simply isn't true. You need : 13mm ring spanner, 17mm socket, 32mm socket and long bar, about a 6" G-Clamp, large plumber's grips, a large flathead screwdriver (for levering hub nut dust cap off) and a little grease. And so I didn't need to get the shrouds off, or grind the edge off the old discs. I fitted new ones as they are cheap.

So new discs: £40, new pads: £15. Cost to me £55. From Fiat to do the job: £215. Anyone in LEICESTER wanting it done, I'll charge you £75 and you get the bits, saving you £85 over the Fiat price. PM me if interested.
Thanks for the help chaps, particularly deckchair5.

 

[Argonought]

Ignore what others say about needing a special tool, it simply isn't true.

I don't know what searching you've done but there are a huge number of posts on this subject.

Some find it straight forward and others find it a nightmare (often with something getting broken )

Using the tool it's ALWAYS easy - and for something that only costs about £15 - then it's any easy decision