Loose on clutch pedal, stiff brakes.

Hi.

I’ve some issues with clutch pedal. I’ve looseness on return which is very annoying. I can say it’s about 1-2cm. A few months ago I’ve replaced whole clutch kit including flywheel.

I suspect vacuum pump failure as I don’t get any fault codes. I can hear different engine work sound when I waiting on red lights with brakes on and when I release the pedal. Also brakes are quite hard. I’ve done simple test pumping brake pedal while an engine was off hold it and started the engine. The pedal went down a bit. I’ve no brake fluid loss.

I started thinking about replacing the vacuum pump, and found vacuum pump 03L 145 100 J it’s quite expensive. I just wonder if anyone replaced it with eg pierburg one which is less than 1/3 off price genuine one? Also I found the pierburg one cover all versions of vag vacuum pumps. So I started thinking maybe it is possible to use genuine vacuum pump but with different end letter?

Superb 2014 2.0 tdi cr 140 cffb.