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I've been changing the rear discs today on the Abarth 595, or to be exact the rear disc, still need to do the other one
All I can say is what a faff, I think Fiat had a bit of an 'Alfa moment' in their design there - making the rear wheel hub in such a way you have to remove the whole stub axle to take the brake disc off, and in the process most likely snap your ABS sensor off whilst trying to remove it.
After spending an hour trying to find out what torque to retighten the stub axle bolts on replacement should be (120nm I think) and a further hour carefully unhooking the handbrake cable, removing the caliper and attempting to remove the ABS sensor before my bottle gave out, I decided to try something a bit different.
I loosened off all the stub axle bolts to within a few threads of coming off, then with a little careful prying freed the stub axle enough so I could twist it a bit and fit in a standard hex key in the top bolt, meaning I didn't have to completely remove the halfshaft to get the caliper carrier off. So one small win.
And then whilst finally removing the carrier I cursed the design of the hex headed bolts which held it on, and wondered why the heck Fiat used them rather than a standard bolt, like Subaru. And then I had a brainwave - I had 4x spare rear caliper bolts left over from my last Subaru build so dug them up for a quick comparison - same thread pitch and length:
So then gave it a quick try in the caliper carrier - fits like it's meant to be there
Admittedly it doesn't look as 'chunky' as the Fiat original, but given the Subaru rear caliper design is identical (except for the handbrake) and the Subaru is a much heavier, usually more powerful car with a more substantial rear brake assembly, the smaller Subaru bolts should be well up to the job of holding the Abarth rear caliper in place.
So fitted the caliper holder up with the Subaru bolts - success! (note the ring spanner fitting with plenty of clearance near the top of the pic)
Not much help this time round, but next time round it'll only take a few tweaks with a normal spanner to get the caliper carrier off and replace the disk, rather than ages struggling and worrying about potential damage. Should be simple enough to pick up rear caliper carrier bolts for a 2004-2007 Subaru Legacy from somewhere like importcarparts, but I suspect there are many other similar caliper carriers around on other cars which use the same type of bolt.
I'll be monitoring it for a while just to make sure it's stable, but if nothing goes awry this could be a very simple fix for one of the Abarth's most irritatingly pointless jobs
NOTE: If you do plan to try this, use proper hardened steel bolts from another caliper carrier of the same length, pitch, etc. Stick any random old bolt in there and you might get to witness the lovely sight of your rear brake calipers flying past, shortly followed by you making an interesting journey into a ditch if the softer bolts strip their threads or shear off under heavy braking.
Also please do not attempt this if you don't understand anything in my rambling above or don't have the correct tools (including a torque wrench, suitable crows foot socket for your new bolts and access to the correct torque specs for everything) - far better to waste a couple of hundred quid getting a specialist to do this poxy job than risk a trip to A&E or worse.
All I can say is what a faff, I think Fiat had a bit of an 'Alfa moment' in their design there - making the rear wheel hub in such a way you have to remove the whole stub axle to take the brake disc off, and in the process most likely snap your ABS sensor off whilst trying to remove it.
After spending an hour trying to find out what torque to retighten the stub axle bolts on replacement should be (120nm I think) and a further hour carefully unhooking the handbrake cable, removing the caliper and attempting to remove the ABS sensor before my bottle gave out, I decided to try something a bit different.
I loosened off all the stub axle bolts to within a few threads of coming off, then with a little careful prying freed the stub axle enough so I could twist it a bit and fit in a standard hex key in the top bolt, meaning I didn't have to completely remove the halfshaft to get the caliper carrier off. So one small win.
And then whilst finally removing the carrier I cursed the design of the hex headed bolts which held it on, and wondered why the heck Fiat used them rather than a standard bolt, like Subaru. And then I had a brainwave - I had 4x spare rear caliper bolts left over from my last Subaru build so dug them up for a quick comparison - same thread pitch and length:
So then gave it a quick try in the caliper carrier - fits like it's meant to be there
Admittedly it doesn't look as 'chunky' as the Fiat original, but given the Subaru rear caliper design is identical (except for the handbrake) and the Subaru is a much heavier, usually more powerful car with a more substantial rear brake assembly, the smaller Subaru bolts should be well up to the job of holding the Abarth rear caliper in place.
So fitted the caliper holder up with the Subaru bolts - success! (note the ring spanner fitting with plenty of clearance near the top of the pic)
Not much help this time round, but next time round it'll only take a few tweaks with a normal spanner to get the caliper carrier off and replace the disk, rather than ages struggling and worrying about potential damage. Should be simple enough to pick up rear caliper carrier bolts for a 2004-2007 Subaru Legacy from somewhere like importcarparts, but I suspect there are many other similar caliper carriers around on other cars which use the same type of bolt.
I'll be monitoring it for a while just to make sure it's stable, but if nothing goes awry this could be a very simple fix for one of the Abarth's most irritatingly pointless jobs
NOTE: If you do plan to try this, use proper hardened steel bolts from another caliper carrier of the same length, pitch, etc. Stick any random old bolt in there and you might get to witness the lovely sight of your rear brake calipers flying past, shortly followed by you making an interesting journey into a ditch if the softer bolts strip their threads or shear off under heavy braking.
Also please do not attempt this if you don't understand anything in my rambling above or don't have the correct tools (including a torque wrench, suitable crows foot socket for your new bolts and access to the correct torque specs for everything) - far better to waste a couple of hundred quid getting a specialist to do this poxy job than risk a trip to A&E or worse.
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