Vito 112 Cdi front brakes

[VitoVoom]

2002 Vito 112 Cdi 120K miles - front brakes seizing partially on and overheating to the point of that smell after 5 minute test drive at low speed.
Checked pads and found them 60% worn but not to the point of the warning light wires being in contact with the discs.
Could not compress the calliper pistons back into their bores even with the correct tool so fitted 2 exchange callipers and new pads. She now moves off smoothly and brake response is smooth, with no drag but after half a mile or so drag and heating becomes evident as before...
Any help greatly appreciated.....

 

[turbopete]

flexi hoses would be my guess. they can collapse over time and not allow the fluid back into the master cylinder at the same rate as it should, giving the result of a brake/brakes sticking.

replace the hoses and all should be well, id imagine

 

[VitoVoom]

Great first response....

Thanks for prompt help Pete. I'd go along with your thoughts except for the fact that both front flexible hoses have been replaced within the last two years.
My gut is telling me it's a master cylinder issue with fluid not returning promptly as you suggest but I don't know what tests to start with???

 

[turbopete]

im assuming then that the vehicle isnt new to you and this is a new fault? are the pads free in the silders? it could be worthwhile removing the pads and cleaning any crud/rust etc from the sliders where the pads sit, and applying plenty of copperslip or other brake anti seize grease and see if that cures the problem. if a master cylinder issue, id have expected all the brakes to stick, not just an odd 1 or 2

 

[alexanderfoti]

My gut is telling me it's a master cylinder issue

If you are 100% confident with the calipers condition, then that's where I would be looking too.

 

[VitoVoom]

Thanks for further help Pete. Vito is mine from new and this is the first fault with the brakes apart from normal wear & pad changes. Parts changed are listed in my first post. Thinking about your posts, there was a single, unusual and very heavy brake application to avoid a collision shortly before this fault commenced?

 

[VitoVoom]

Further advice

Thanks for input Alexander. Yes 2 x factory rebuilt callipers fitted last week. Do you know of any simple tests I could perform on the master to aid diagnosis?

 

[star]

Are the calipers sliding pins free and the calipers moves when there tight (if fitted as we do not work on vans) ?

 

[VitoVoom]

Thanks for input Star.... Yes, all slides freely at both callipers and only new, clean DOT 4 in the Master. There was a single, heavy brake application shortly before this fault commenced. Only the front brakes are seizing. Are there any tests I can run on the Master Cyl'?

 

[turbopete]

do the brakes start to stick even if theyre not applied between start-up and covering the first half mile or so? that would tell us if its fluid related (not returning) or, possibly servo/abs pump related.

 

[alexanderfoti]

Thanks for input Alexander. Yes 2 x factory rebuilt callipers fitted last week. Do you know of any simple tests I could perform on the master to aid diagnosis?

Sorry didn't see this. If they look good and the rubbers are in good condition, then its unlikely to be the calipers. Pete's advice is good.

 

[VitoVoom]

Thanks Pete I did try just cracking the master cylinder front output pipe joint and the driver's side front brake gently creaked and slackened off. I'm thinking of getting the front end securely supported - wheels off and running her from cold to see if the heat builds up without braking - does this sound OK?
On a different note while I've got the front exposed, I want to renew the driveshaft inner boots as they're split. Once the hub/disc and brake assemblies are manoeuvred out of the way, can you just withdraw the complete driveshaft or is further dismantling required at the inner end?

 

[turbopete]

assuming the vito is FWD (ive had very limited experience with them and never been under one) its a case of strip out to get the outer end of the driveshaft out of the hub, then what id do is get some of those universal fit stretchy CV joint boots, and the fitting cone, stretch them over the outer joint onto the shaft, cut the old inner boot off and fit the new one in the appropriate place. they work brilliantly in my own experience and much easier than removing the shaft, especially as removing the shaft from the gearbox on most vehicles ends up with the oil draining out of the gearbox.

 

[VitoVoom]

Thanks for your perseverance

I'll take her round the block on handbrake alone in the morning and see?

 

[VitoVoom]

Progress?

Hello Pete, Took her round the block at dawn a few times without touching footbrake and no sensation of seizing. In neutral she coasts to a stop smoothly with no braking effect and rolls away as soon as drive selected. However, when later parked I felt all alloy wheels and passenger side front was noticeably warm but nothing like as warm as in earlier tests. Remaining 3 wheels were completely cool. In earlier tests as Hammer had suggested, cracking the master cyl' front output pipe did free up the driver's side front. Could this be to do with what I think in earlier days used to be known as a "diagonal split" system although that may have been long superseded? I'm away for a few days but will be back on the case next Tuesday if you can offer any further advice.

 

[VitoVoom]

Hello Pete, Sorry for few days unavoidable absence. Acting on some other advice I slackened the master cylinder/servo joint and added two horseshoe washers to see if that would cure things by effectively creating more end float in the master cylinder pushrod. Took her out for a quiet trip last evening and although it is difficult to compare as vacuum was missing there didn't seem to be the slightest binding? Is it possible to disconnect the ABS unit electrically and still leave normal non-ABS braking to see if that changes things? Thanks for continuing help.

 

[turbopete]

im not sure the ABS can be removed from the system. have you tried it as it was, but without the vacuum connected? ive come across a few cases now where the vacuum has got excessive and started to pull the brakes on. i think theres a relief valve somewhere that sticks and allows vacuum to keep building up. adding the spacer washers doesnt really make any difference to the ABS anyhow. that just prevents wheel lock. i am starting to think its vacuum related, unless you have had a replacement master cylinder fitted recently?

 

[VitoVoom]

No progress

Hello Pete, Yes they do start to seize without braking over first mile and this is also true when repeated with both ABS fuses out. i.e control unit and solenoid unit.

 

[Kahl]

2002 Vito 112 Cdi 120K miles - front brakes seizing partially on and overheating to the point of that smell after 5 minute test drive at low speed.
Checked pads and found them 60% worn but not to the point of the warning light wires being in contact with the discs.
Could not compress the calliper pistons back into their bores even with the correct tool so fitted 2 exchange callipers and new pads. She now moves off smoothly and brake response is smooth, with no drag but after half a mile or so drag and heating becomes evident as before...
Any help greatly appreciated.....

Hi think is the break callipers sliding crew the go often rusty and the callipers don’t go back in position