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Low brake pressure Volvo l180f 2008

mrcowboy ยท 2015-07-31 15:20

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?

Replies5
  1. #1Steve 6502015-07-31 22:53

    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

  2. #2mrcowboy2015-08-01 08:01

    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.

  3. #3Steve 6502015-08-16 22:39

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

  4. #4mrcowboy2015-08-18 01:22

    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.

  5. #5mrcowboy2015-08-28 02:57

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