Brakes vibrate and lose pressure at very low speeds

not necessarily
if you have abs brakes it is the pulsations as the wheels lock and unlock from the abs activity
this transmits as a pulsation under your foot
it may also mean that the discs have warped and the warp is pushing the piston back in then letting the piston out
it is more noticeable at low speed light pressure stops but it depends on the speed
Take the vehicle to an accredited brake shop specialist and get a proper diagnosis done

I have a Mitsubishi lancer also and I found out after a discussion with the dealer service manager that a similar problem comes from warped front disc rotors. I noticed that there was a slight pulsing of the brake pedal at low speeds but the brakes worked as they should. I went to a brake specialist where I get all my clutch and brake parts and he informed that the genuine rotors are made of inferior metal and warp early in the service life. As they are not covered by warranty I bought after market discs of good quality and the problem went. What I am trying to say is that your low mileage problem is about the same as when mine started. If the disc rotors are warped then at speed the continuous touching of the pads will produce a vibration affect at high speed as at lower speed the vibration will be barely noticeable. Take the car to a reputable brake specialist and have him test the discs as to running true and are not warped.

brake fluid comtaminated, all your seals are probably shot, @ master cylinder, wheel calipers, etc., the combination valve is stuck ., Is your fluid black ? Bleed entire system, completely, see if that helps, otherwise, good luck

Blockage in the lines or calipers possibly warped rotors take to brake specialist for proper repairs and cleaning. I hope this helps

it all depends on the speed and what u are doing at the time the vibration occurrs, if during braking you have warped brake rotors, if at higher speeds tire balance, at low speeds front end wear. Any tire shop will road test and give u an idea of the cost to repair in most cases free of charge.

the abs pump is losing pressure and kicks on when you apply the brakes at all to get up to the correct pressure.

If you get a bad vibration in your steering wheel at low speeds without braking it is either a bad tire or a bad rim. If you get a vibration at speeds around 45-50+ and goes away you probably have a balance issue. If the vibration only occurs while braking then your rotors are warped. If low speeds it shakes i'd take it to a shop to check your tires.

A bad tire, a loose wheel, a loose tie rod end, a bent rim, (tire balance at higher speeds), a piece of rust or whatever caught between the rim and brake rotor, or between the brake rotor and hub. Have you done anything to it prior to this starting?

I had this issue and it was one of my winter tires about to blow out, showing signs of weakness.. hopefully this helps!

Clutch would show different ugly symptoms - it is definately a warped/warn rotor and/or brake pads from high speed deceleration or "riding the brakes".

Fairly easy to fix, probably 2-3 hours of work for each corner

ITS STILL UNDER WARRANTY! LET THE DEALER TAKE CARE OF IT.