I have an odd problem with the clutch on my 2005 420dci Premium. It isn’t a big problem, and it is something it has done all the time I have had it (which is just over 12 months now) but it is a bit annoying so as long as it isn’t going to cost me too much I would like to get it sorted.
The problem is this. When the vehicle is cold, the clutch pedal doesn’t return right back to the top when you don’t have your foot on it. As the thing warms up it gradually comes further and further up until eventually it rests in the normal position right at the top. When the weather is colder it takes longer to sort itself out. In the summer, it sometimes doesn’t do it at all, and if it does, it only takes a few minutes to start behaving. In the colder months it can take an hour or so and even once it is warmed up if you go through some cold weather (rain/snow/etc) it sometimes starts playing up again during the day. You can always put your foot under the pedal and bring it back up to the top yourself with minimal resistance even when cold.
Now this isn’t affecting the actual operation of the clutch at all. It doesn’t slip or anything bad like that. In fact the only reason I want to sort it is that when it doesn’t come right back up it doesn’t activate the switch that tells the truck’s brain that the clutch is up, and so you can’t use cruise control or the exhaust brake.
Sounds like the slave cylinder prob that I used to have on an old car, expensive to split engine from gearbox to replace a £40 part. Hopefully it may be the master cylinder, more expensive part (possibly) but hell of a lot easier to get at & replace, hence cheaper labour.
Is it losing fluid? if so where? drips from the bell housing indicate slave, wet around the pedal, linkage, reservoir obviously the master cylinder.
Not that I’ve noticed. The fluid level hasn’t needed topping up in the 12mo I’ve had it certainly.
shuttlespanker:
what gearbox is it?
ZF 16 speed with the slapover range change.
You mention that it is hard to bleed… Well, when I got it whatever the part is that sits under the gearbox looked almost brand new as if it had recently been replaced, I’m guessing this is the slave cylinder. Could it simply be air in the system? That would make sense as air will noticeably expand and contract as the temerature varies. When it’s hot it will take up more space and perhaps push the pedal up further?
if it was a new part when you got the truck, then yes, it could be air in the system
the first thing i would do is to drain the system completely, then refill it FROM THE BOTTOM UPWARDS
if you fill it from the top, it can get air in the system easily, but, if you fill it from the bleed ■■■■■■ on the slave cylinder, you are forcing the fluid up through the system and not letting gravity pull it down
try that, then report back
repton:
MADBAZ:
Is it losing fluid?
Not that I’ve noticed. The fluid level hasn’t needed topping up in the 12mo I’ve had it certainly.
shuttlespanker:
what gearbox is it?
ZF 16 speed with the slapover range change.
You mention that it is hard to bleed… Well, when I got it whatever the part is that sits under the gearbox looked almost brand new as if it had recently been replaced, I’m guessing this is the slave cylinder. Could it simply be air in the system? That would make sense as air will noticeably expand and contract as the temerature varies. When it’s hot it will take up more space and perhaps push the pedal up further?
Yes that will be the slave cylinder it will have a bleed ■■■■■■ Near the very back of it. It’s just your luck with bleeding it. Some trucks are a c£&t and other are spot on!
It’s work your wile if u have like a jam jar Half full of brake fluid and a Jose from the ■■■■■■ to jar when bleeding! It’s a two man job!
Check level and if low top up
Pump brake until its hard and can no longer pump, keep your foot on the brake whilst you open the ■■■■■■ ensuing the pedal goes to the floor once it’s down close ■■■■■■ and repeat untill no air is coming out, I always give it an extra 5 goes once the air is out to make sure
repton:
Turns out it was indeed air in the system, my fitter pumped a load of fresh fluid in the bleed ■■■■■■ on the slave cylinder and the problem went away.
Thanks all for the advice.
Paul
It is often good advice on here, some people can understand it, many can’t.
Bleeding can be a pain on cooling systems too, if it doesn’t work properly, fill it from the bottom
