I’ve got a little bit of a head scratcher. I’m fairly inexperienced with hydraulic brakes but I am pretty comfortable working with mine.

My MTB has Shimano Saint levers and Magura 4 post front and 2 post rear (MT5/7 I think) for a Shigura setup. It’s *****in, I like it so much better than the Magura Trail/Sport levers I used to have.

Anyway, after i set it up this summer, I went on several rides. They were flawless. I was riding fairly often if that matters.

A broken rib, smoky air, and emphasis on rock climbing means I haven’t ridden that bike much in maybe 6 weeks .

3 weeks ago I noticed my front lever went all the way to the handle. Not on a ride, just on a park cruise with my 5 year old. I took it home and bled it and it was fine. I got quite a bit of air out. I figured it was leftover from the initial setup.

Today, I figured I’d ride tomorrow. I checked my brakes and the rear went to the lever and the front was spongy.

I bred them again and got quite a bit of air out of each. Like kind of a surprising amount.

I’ll ride tomorrow and I’m sure it’ll be fine. Will it need bled again after sitting next time? All mine and my wife’s bikes don’t have these issues. They’re good for literally years.

I’m sure it’s my fault. I wonder what I’ve done wrong.

Here are my ideas.

-The mineral oil I used is generic, not name brand, it’s also been opened and stored with the lid closed. Does it absorb air from the environment?

-I have MAGURA lines and Tecktro barbs and olives. It all fits. There are no visible leaks and I ride in ultra dusty Central Oregon, it would be noticeable. I don’t think this is the problem but it’s worth mentioning.

-The lines are 2 years old. Again, no leaks. No dust accumulation.

-My process. A syringe at the caliper, a funnel at the lever. Lots of moving back and forth. Lots of line tapping, lots of lever flicking, and then a deep cleaning with denatured alcohol. Seems right.

-The bike is stored vertically. Maybe saints are more finicky about air rising into their levers.

-It’s possible that I’ve gotten all the air and they’re good for a long while, this was just a hiccup. I’ll know in a few weeks/months I suppose.

Given what I’ve said here, what, if anything would you recommend looking at next?