Volvo vnl air assisted hydraulic clutch 

My 2014 Pete 579 has one.

Is it pretty easy on your 2021 t800 I had 07 kw t600 sweet truck but unfortunately I had to sell it cause it fuked up knee after pressing 100s of thousands time in 10 years

I like it. It greatly helps the old leg out. lol

I have seen even some tractors using that

To be honest I can not imagine how to control a 800Nm (corresponds to about 150kW/1800rpm) or above rated clutch directly, without any form of engine power assist. By the way the "most modern" truck above 7 tons without any power (essentially air) assist I've ever met was Praga V3S from early 50's and this video was a surprise for me it was even feasible to make the clutch work without... All later, include busses, used air assist, where you practically can not operate the clutch without the air pressure at all. I have even heard a story from my dad about the servo valve being faulty on an (Ikarus 280, power train was some MAN license from the 60's or so), so the clutch had to be operated by just a brute force. Well, the seal in the master cylinder gave up to the pressure and he had to get moving on a starter and then "float shift" in order to get the bus "home" (of course, without passengers)...

Yep, pretty nifty design they got. I figured you might have ran across this on something another with all the trucks you get to work on.

Well, in Europe from about 6 heavy truck or bus types with a manual transmission designed along 50's till now, I'm familiar with to this extend, all used essentially the same system. And based on what was in the taught in the driver traning course, my impression was none above about 7.5 ton existed without such system...

Wow, didn't know it had been around that long, I like it. Much more driver friendly not having to stand on the clutch pedal.

I drive a 06 VNL...same thing, just keep the fluid level full. My fluid level got low, and got that hard pedal too. I read somewhere too that if you think you don't have quite enough pedal free play, that's almost normal.

Same with my 14 Pete 579.

Only thing I can think is check the air pressure going to the slave cylinder, make sure clutch is properly adjusted and check the clutch brake...

chase5726 there no air line going to it .. plus it is a automatic clutch

Yep