Low brake pressure Volvo l180f 2008

I got a little problem with my loader today.
I got a message that says: Low brake pressure. I checked the pressure in the display and when i push the brake pedal down it climbs from 0 up to 75 bar.
And the acc pressure says 135 bar when there is no warning. if i push the pedal 5-6 times its start the pressure becomes under 80 bar and then the warning comes up in the display.

How do i check that the accumulators is ok?

I think thats something wrong with the charging system becouse the fan is moving slowly and the engine overheated one time today.

Anyone got any ideas?

remove the accumulators and check if you are able to push the diaphragm in the center with a screwdriver, if so they need to be change. Or you can put a special fitting and check the pressure reading with a body jack, if the pressure in under 500 psi, need to be change. As for the fan trouble, when unplugged the MA5502 and put the fan in test mode from i-ecu, give full throttle and you should have 3050 psi at the PFF port on the central valve. If not you have a failure at pump adjustment, max working brake, by pass at coil MA5502, hydraulic fan motor case drain, VECU not sending the right voltage or wiring issue, wrong cut in/cut out signal from sensors... hope it helps

Today when the machine was cold it was no problem with the brakes or the cooling fan but i did the fan test and it peaked at about 2800psi and then it sunk really quick to 2300 psi.
I checked the ma5502 and it seems to work and i couldnt see anything that was worn out on it.
is it possible that the pressure is to low from the pump? Should i increase the preussure on the pump? Where do i do that.

pressure should be at 3050. Pressure is adjust directly on P3 pump flow compensator.

Im going to change the ma5502 valve and see if its get better before i increase the pressure.
Ive ordered the valve but its havent arrived yet.

Now i have changed the ma5502 and it didnt solve the problem. Is there anyway i can test the ls pressure on p3?