Clutch problem

Hello friends, I have a problem with two vehicles and I think that in both cases it is clutch, to see if you give me any solution that is not changing it.
Both in an 806, and in a megane, when the slopes there are times that the engine is accelerated and the speed does not increase.
In the megane at first it was attributed to the pump taking air, but in doing so now the 806 I have proven more details.

When it accelerates and does not increase the speed is in fourth, in large slopes and without carrying the car thrown. If you go to third and the accelerator is sought, the revolutions rise and increase the speed.
In both cars, with the car stopped if it gets first and clutch is released with the brake, the engine is crowded (the clutch does not skate).

I understand that in the fourth rise of revolutions and does not increase the speed because being a longer march the clutch has to make more strength and skate. The ideal solution already knows what the clutch is changing (if it is clutch failure).

My question is, is the failure because the maza spring is yet giving up or because the album is greased in some way?

If it is because the disc is greased, I understand that water could not be put under pressure and washed because the collar bearings would be washed and they would end up annoying.

If it is because the docks of the mace are losing tension, there is some way of taking more route to the pedal to extend life a little more or you may believe that it is something else and not as a clutch. Thanks in advance!

Hello friend, I am a macanic and I can tell you that the problem is due to the wear of the album, if they were the docks Daria pull the raging or when the car begins to come out.
It is only wear of the album, and in case it was for the pressure or press dish, it always sliding, it would also pass in the future if the album wears more, it is always advisable to change the complete set (press, disc, roller)

It is seen that I am a rookie. I gave the Thanksgiving button, but it was not to thank the subject but to thank the one who answered me.
Rubén, thanks for your answer. I understand that both clutch sets are already playing.

No rookie or not, we are here to help and indeed as Ruben says, that symptom is made of the album, but you change the set so you ensure your work, since the clients arrive in the occasion for the month because it fails and now it is the fault of the press but they want their guarantee., well there is no more to make the clutch kit, the regulation is only for the pedal and nothing more if the album is spent there is nothing to do, and there is nothing The set, that is not done hahahaha, it is of no use just to get wet when you have to take it out and finish killing the disk and bearing.

Cristian, thanks to you also for the answer. Well I know that I have to change them , to see if it endures the passage of the holidays.