Intermittent Squishy Brake Lever 2015 850 SP

I was moving my 850sp around the other day getting things ready for a trip next weekend and I left the quad on my trailer over night to be transported with me to work in the morning and I had left the parking brake on.

The next morning i went to move it off the trailer at the shop and noticed the brake lever felt kinda squishy. Normally I can’t squeeze it to the bar, but it squeezed right down to the bar, I assumed it was because i left the parking brake engaged and stretched the lines (I realized that doesn’t make any sense, polaris uses nice stainless lines). Sure enough after a couple minutes the brakes went back to normal, very very stiff brake lever.

Since then though, I noticed that at random the brakes will get squishy and go to the bar, then I’ll release them and try again and they’ll be rock solid again. I consulted a good friend of mine who’s been riding and maintaining Polaris sleds and ATV’s his entire 34 years of existence, he seems to feel it’s a check valve in the master cylinder not doing it’s job all the time. He said he had a similar experience once on his father 2012 850XP, but it cleared up and they never pursued it.

There’s no sign of leaks and the reservoir appears to be full, has anyone else ever experienced this?