Grunta How old is your machine (when was it manufactured), as although Jake is correct…he is only correct for earlier models. The Vostok has used compression fittings on the back of the steam/water arms for a while now, probably 6 months or so. The Evo doesn’t have space to allow the use of them.
P.S. Even before those dates of compression fittings (on Vostok), flexible sealant began to be used around 2 to 2.5 years ago which also makes the problem far less likely to occur. It was caused by the expansion and contraction of the metals and a permanent (non flexible threadlock). The semi permanent is not only much easier to remove, but is flexible which alleviates the problem.