Sram Level back brake dragging

Mine had that issue on hot days too.  Common problem with a certain model / year.  Some sort of plastic piston / plunger would expand in the heat.  From memory you can replace the part but it looked like a pain.  Instead I just wrapped the brake in tin foil when it was sunny which did the trick....

Thanks r8jimbob88,

That's a pain, and I don't fancy putting tin foil on my brakes, it's bad enough with this tin foil hat on 😉

When I had Levels I didn't like the amount of freestroke before the pads engaged. So I pumped the pistons out a bit and then topped up the master cylinder/lever with more hydraulic fluid. Wonder if you try doing the opposite i.e. push the pistons back in but ensure the bleed screw on the lever is left loose so any excess fluid is squeezed out.

I've got a few of these brakes on my build-kit bikes and 2/3 of the bikes' level brakes have gone this way. I decided after messing with them and taking mechanic advice to bin them off.

Definitely a hot weather thing - once they start they get worse - and I wouldn't have specced them but these bikes were pandemic models and I didn't get much choice at the time.

You need the replacement piston, done this on my 2016 Guide RS's - stuck within the first two years, both replaced. Not had any issues since.

Should be easy on the 'Level' - was fairly straight forward on the Guide RS (some extra hardware in the lever).  You'll need to remove a tiny circlip - bit small for circlip pliers, so I used a 'bit' from a precision screwdriver kit to prise the clip out. Pushing back in, requires you to hold the new piston down whilst putting the clip in, so two small screwdrivers.

Thanks all for the replies and advice, at least I know it's a known issue that can be fixed.