Sprinter has lot of travel in brake pedal

[motovelo]

My Merc 412 Sprinter seems to have loads of travel in the brake pedal but my local garage claim they bled them up? They have been like this for ages since I bought the van a year ago, pads are all fine and the only thing I've ever done is replace the front pads and remove the pad wear sensors as they were a bit worn and caused the light to flicker. The brakes work fine but can catch you out if you have to brake suddenly! Somebody told me this is perfectly normal on this model, what do you think, might they just need bleeding? The same local garage suggested there might be some sort of brake enhancer controlled by the ECU but they couldn't figure it out and I'm wondering if this is also why the electronic milometer flashes the moment the van moves??

 

[IAN MAC]

Yep, my brakes are the same, long in travel but got a bite at the end.
As for your mile reader, it just clips onto the circuit board of the dash unit so may just be a poor connection. May even be the multi plug, but you'd have problems with other parts of the unit too.

 

[dava]

Sprinters are known to have crap pedals, MB say they dont! But hell what do I know? Couple of things may help, check the back calipers, the 2 x 13mm bolts that hold the caliper on to the pad housing (sliders) are prone to seize up and instead of the caliper sliding it flexes on the housing and gives a spongy feel, it's the tubes these fit into that seize, regulary have to fit complete calipers because of this fault. Secondly if you can, get it presure bled, this sometimes works as if there is a small amount of air in the system it can realy improve the feel of the pedal and reduce travel. Lastly and only after you have checked the others, get it bled using the Star diag, called an extreme bleed, this operates the solenoids in the ABS pump and can clear small amounts of air trapped here.
Hope it helps.

 

[motovelo]

Thanks for that will check the rear calipers tomorrow and will have a go at bleeding the brakes this Weekend.

 

[motovelo]

As for your mile reader, it just clips onto the circuit board of the dash unit so may just be a poor connection. May even be the multi plug, but you'd have problems with other parts of the unit too.

Thanks for that I'll check it hasn't come unclipped. It still records the mileage but like I said as soon as the van is put into gear the numbers flash? There is also a warning triangle at the end of the mileometer reading, any ideas?? Been like this now for months so I'm assuming it's no big deal? I wondered if it had anything to do with the tachograph that is still in place??

 

[dava]

Thanks for that will check the rear calipers tomorrow and will have a go at bleeding the brakes this Weekend.

Bleed them diagonly, N/S/R first then O/S/F then O/S/R and N/S/F. Also use a good qaulity brake fluid we use Semi synthetic dot 5.1 and strangely enough new MB only use Dot 4.1,????

 

[Cnics]

Just to add, my pedal is the same. the brakes work very well, just a crap pedal really, i often hire them aswell when i need more in the fleet and they are all the same. The sensors often dont see many sets of pads before they need changing, often merc will do them each time. they are also prone to braking causing the light to come on all the time (had pads front and back recently replaced and the light is on all the time now).

Rob

 

[television]

Just to add, my pedal is the same. the brakes work very well, just a crap pedal really, i often hire them aswell when i need more in the fleet and they are all the same. The sensors often dont see many sets of pads before they need changing, often merc will do them each time. they are also prone to braking causing the light to come on all the time (had pads front and back recently replaced and the light is on all the time now).

Rob

The lights can come on if the fitter used the copper grease and got it on the ends of the pads. there are copper free greases on the market now. (TMD)

malcolm

 

[dava]

Probably faulty sensors, they had a batch of them. More than likely the rears, get underneath and disconect from the cliper, not the pad as it wont go back in. One at a time to see wich is faulty.

 

[daz 585]

moto, the tacho problem?/ press the inner button on the bottom of the tacho switches do both ok, it may give you a tachograph if NOT ask around or find a decent truck driver and ask him if you could have to charts "pear type", put the tacho in the tiny little slots 1 per slot,it will click and make a few silly noises and prob the speedo needle will swing right round to 140kph and may do this a good,good few times nothing to worry over, and then!!! you should be ok with the milage flashing,,
all it is doing is saying you havent a tacho disc in realy,
unless its like mine which i broken as i stripped it fully down all internals out and made a silly mistake building the tacho head back up so no it permintaly flashes "****** thing". but make sure the tachos are in with ign turned off, it should feed in ,,
and as every one says pedal travel is the norm, best thing to do?? is jab the peddle and let it of thenbrake peddle travel reduces then!!
long live the 412 sprinters

 

[daz 585]

moto, make sure you have either the plastic chart or a tachograph in the tacho head, put the discs in with the ign turned off aswell,, and let the tacho load the disc up, then turn ign on, it may send the speedo needle right round the face of the tacho head a good few times but nothing to worry about, if this doesnt stop the milage flashing make sure you have the speed warning set above say 120 kph you do that by pressing the little buttons to alter speed warning the triangle could mean a number of things first one is no tacho in head, or it could mean a power fail even for a split second this will cause the milage to blink its a ****** pain sometimes put two discs in aswell 1st disc must be in top slot,try that and then try the other disc in the bottom slot!! its for double manning, but you use the very top slot 1st, just in case you dont know,, anymore questions give me a shout bud ok, daz

 

[battwell]

i sorted it on mine!

on my 312 with 300k i had excessive brake travel which passed the brake test on mot but the tester wasnt happy with the amount of travel. nor was i as it seemed too close to floor. i had changed fluid, new disks and pads. checked brake compensator valve etc etc.
i removed the 2 nuts holding master cylinder to bulkhead and pulled it out with pipes still connected. behind here there is a splined nut which i turned outwards a quarter turn. brake pedal is now exactly where it should be.
caution, i tried turning it another half turn to be smart but the brakes bound solid when warm so be warned dont over do it.
i had already ruled out flexing hoses or dodgy master cylinder by clamping hoses near wheels and pressing pedal hard with no sink or spongieness.
check wheel temps after doing it to make sure nothing is binding after a short drive around the block.
hope this helps you all.

 

[D19NNO]

I've had this issue replaced the servo, master cylinder, new discs and pads. Bleed the brakes to excess and wound out the rod on the rear of the master cylinder
All seemed fine until the rear brakes started binding in hot weather a week ago seemed odd both rear brakes were binding at the same rate so checked the load apportioning valve to find it was sticking. Freed it off with wd40 mole grips etc then my brake pedal went rock solid, re wound rod at the back of the master cylinder to original position and hey presto that was my problem all along.
I didn't realise they had to move so freely.
Do not completely remove this as the set up on the rod is sensitive. Also check the return spring isn't broken etc.