# Ducato Front Brake Calipers



## Trunkles (Jun 13, 2013)

Can anyone tell me the size of the HEX BIT needed to undo the caliper bolts on front brakes of a Ducato 2.3 JTD.    

 Aky failed her MOT because the discs are corroded because she stands outside for long periods and we live in Weymouth with lots of salt in the rain when the gales are blowing, so need to renew discs and pads.

HAs anyone experience the root problem of corrosion when standing outside.......is there something I can do to the exposed disc surfaces to stop it happening?

Thanks in advance for any help.


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## jeffscarborough (Jun 13, 2013)

Are you sure they need replacing?
My camper stands outside at the seaside for most of the year, but the discs soon clean up when its had a long trip and I have pressed the brakes hard a few times, the pads are abrasive and will clean the cast iron discs.


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## Trunkles (Jun 13, 2013)

No choice, it failed its MOT today so have to do them.


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## Smaug (Jun 13, 2013)

Yeah, I'd be inclined to go for a good drive with plenty of brake use before getting a retest at another garage.

Clearly you cannot spray or coat your disks with anything without adversely affecting your braking capability. The old adage of "Use it or Lose it" springs to mind. 

For a car you can get inflatable garages with a small air pump, filters & condensers to ensure dessicated air only enters & pressure is greater than outside. Not realy practical for a motorhome tho really is it?


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## Aladdinsane (Jun 13, 2013)

14mm


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## Trunkles (Jun 13, 2013)

HI Smaug,

We did take a long drive to clean up the discs....200 + miles to Derby where we cleaned off the hard iron oxide skin that had formed during the course of servicing by my son in law.  The we drove back to Weymouth.   Result - brake pads still only acting on the bright area of disc and no cleaning or abrading of the corroded area. You'd have thought that distance would have done the trick with all the braking.   I must be very soft on the pedal!

Can Anyone tell me what torque setting when tightening the caliper bolts please?


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## Smaug (Jun 13, 2013)

Trunkles said:


> HI Smaug,
> 
> We did take a long drive to clean up the discs....200 + miles to Derby where we cleaned off the hard iron oxide skin that had formed during the course of servicing by my son in law.  The we drove back to Weymouth.   Result - brake pads still only acting on the bright area of disc and no cleaning or abrading of the corroded area. You'd have thought that distance would have done the trick with all the braking.   I must be very soft on the pedal!
> 
> Can Anyone tell me what torque setting when tightening the caliper bolts please?



I can't help with torque settings, as I just wanged 'em up as tight as I could when I did my car. 

There is often a few millimetres of corrosion outside & inside the swept area of the pads. Are the pistons moving in the calipers, as they often seize if standing for long periods. If the corroded area is lower (ie disk is thinner there) than the polished area then the pads won't reach it until they wear down a bit, but corrosion usually means rust which is thicker than good steel. Are the disks deeply pitted or grooved? 

Disks can be machined (skimmed) when badly ridged, but there are wear tolerances (minimum permitted thickness) beyond which it is not safe or practical to go. :drive:


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## Teutone (Jun 14, 2013)

has it passed the test on the brake rollers? Brakes don't need to look pretty, they are there to stop you.
So as long as the disk has the minimum thickness required and passes the brake test, I would argue the MOT failure because of a visual comment


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## maingate (Jun 14, 2013)

Teutone said:


> has it passed the test on the brake rollers? Brakes don't need to look pretty, they are there to stop you.
> So as long as the disk has the minimum thickness required and passes the brake test, I would argue the MOT failure because of a visual comment



I think the MOT failure would have been because the discs were 'pitted'. This is not surface rust but pinholes appearing in the steel.

The mechanic who does all my jobs told me to drive like a boy racer for a while as there was slight pitting appearing on my discs. That will not help in more serious cases, he was just putting off the inevitable for me.


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## runnach (Jun 14, 2013)

Discs and pads replaced on My Ducato last year, I hope you are built like Arnie to get the buggers off....In the end my uncle Arfur did it with extension bars and his strength ( hes a big lad ) and tools designed for trucks TBH I would have struggled on a driveway.

Channa


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## Trunkles (Jun 15, 2013)

Aladinsane.....thanks for the hex bit size....I am going out today to see if I can buy a single bit for the job.

Teutone.....she failed the roller test because the nearside is worse than the off and the brakes are not balanced. when I looked at the disc the outboard pad is working on the centre-wards portion of the disc and the inboard pad is working on the section toward the rim, but covering more of  the disc.

Channa..... I have solved the release problem already......I tap lightly with a 1lb hammer on the side of the disc hub as I rotate the disc and this loosens the build up of corrosion that  'sticks' the disc to the bearing hub. After  a minute or so of this the dics floated free, much to my delight. If that had failed I have a large hub puller which I could have used.

Thank you all for the interest in the thread, but I still need to get some idea of the tightening torque for those caliper bolts so if anyone has a Haynes or workshop manual for Ducato could you please look it up for me.

Cheers


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## Trunkles (Jun 15, 2013)

*Job done...new discs and pads fitted.....Cause of problem :  DISINTEGRATING PADS!*

Well now I know what Channa meant when he said he hoped I was a bit of an Arnie....I now have aches in muscles which I didn't know I had!

The caliper bolts were pigs to get out......they had been torqued up very tight (over 100 Newtons) and also thread locking compound had been applied. Even on my lorry jack I couldn't get Aky high enough to get a decent swing but with the aid of an extension tube on my fixed head socket wrench and my brand new 14mm Hex bit socket I was able to free the bolt and then undo them at a tortuous one twelfth of a turn at a time. As they came free I changed over to a ratchet head which eased things a lot.

Cleaned up, the bolts went in a lot faster than they came out, finishing with my torque wrench at 90 Newtons.  My mecahnic son in law was surprised by the use of 'Locktite'   but said the specs may demand it if there has been an issue discovered by Fiat so advised I put the bolts back with it.

Now to the real issue ........the reason the brakes weren't operating efficiently was that the pads were disintegrating ( one actually fell apart as I took it out of the caliper) from the exposed edges inwards and looked like coal briquettes with the ends crushed.   When I examined the edges of the pad material it looked as though they were starting to delaminate through the thickness of the pad.

So in effect there was no pad where the discs needed to be cleaned by some hefty braking action and hence the build up of a thick hard skin of rust. Any heavy braking allowed this hard rust to cause further disintegration of the pads. I wonder what would have happened to the pads if I had needed to stop in a real emergency braking situation ?

Maybe there is a warning here for any one who has a Motorhome/vehicle of some age but low mileage who assumes as I did that the pads were OK. After all I was told by the mechanics who did the MOT that there was plenty of thickness in the pads. They just couldn't see that they were slowly breaking up! And maybe visual inspection without dismantling is just not enough!  I shall certainly be looking harder at the pads when checking Aky over in the future

I can only think that the pads and discs are original ( only 30,000 miles on the clock) but as Aky is 9 years old  the padswere breaking up due to age and stress fatigue.


Thanks for the interest and all the help and advice.

Trunkles


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## Smaug (Jun 15, 2013)

Thanks for the feedback. The odd swept area on the disks was the tell tale we missed! Very useful to know, thanks. :rabbit:


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## CelticRambler (Jul 9, 2013)

Aladdinsane said:


> 14mm



That's what the guide on the FIAT forums says, but no-one I've spoken to has ever seen a 14mm hex key, let alone used one - and that includes doing the rounds of every DIY shop in my neighbourhood (central France). :sad:

However, I've just come in from changing the pads on my 2003 Ducato 2.8, following the FF instructions and the bolt unscrews using a *6mm* key. The pads (and accessories, including bolts) are described as suitable for the 2.3 aswell. :idea-007:


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