Hello guys, i have a mk1 punto td, while under the bonnet i noticed something, the check valve of the brake booster is too loose, it doesn't come out but it spins easily, and while driving, the brake pedal becomes too hard every now and then
1- so is it normal for the check valve to be that loose, if no what do i need to change?
2- how am i supposed to remove the check valve? i tried a little but i was afraid to break something, also the hoses are too tight, how to pull them off?
3- i have some blowby symptoms: power loss, fuel consumption, oil loss: on start there's a huge cloud of smoke coming out of the tailpipe and while the engine is running the breather emits a strong stream of oily smoke, so that the air filter housing contains oil (i clean it before starting the engine), i can't add oil even when level is low, i did last week (something like 1/2 liter) i turn the engine on and it felt like it was going to explode and the dipstick was oily 10cm above the max level, so i had to remove some oil. 3 or 4 days ago while the engine was running (and the weather was hot), after 2 or 3 cycles of cooling fan run, the fan came on and it didn't want to stop until i pulled the dipstick out, it stopped after a little while
Note: i changed the piston rings recently

rad fan stopping when pulling oil dipstick out is luck
did you have all these problems before changing piston rings?
maybe something wasnt put back together correctly

the fan didn't stop immediately after i pulled the dipstick, it went on for some time it stopped for 5 sec then run again a little
the problems were there before, and i changed the rings because of those problems, also the work was done by a mechanic
so any clue about that check valve?

smoke like this?

Nope, the tail pipe smokes only when the engine starts