930 G cat loader brake alarm going off

This topic contains 1 replies and was last updated by joe-dirt 6 years 8 months ago
Author
joe-dirt
June 17th, 2014 10:07am
Post
I have a 930g cat loader and the brake pressure warning light/alarm keeps going off when the pedal is pressed , we have tested the brake pressure at 750 psi and have also checked to make sure accumulator Is working it is putting out 750 at first hit of the pedal and approx. 100 psi every hit there after I have had the brake valve apart and resealed couldn't find anything wrong with it, also replaced the sensor on the brake valve and the sensor on the brake/fan hyd pump that drives off of the engine . cat is telling me the brake pressure is ok at what I tested . what am I missing that would set the light /alarm off ? please help thanks!
andy-stoecklin
August 12th, 2014 10:53pm
Hi Joe. I am not a CAT mechanic. I can just give you a couple of general ideas. Run the machine until the warning light is off. Shut off the engine and turn the key back on. How many times can you press the pedal before there is no more pressure in the system? On machines I work on it takes about 30 applications to empty the brake accumulator. With a gauge installed at the accumulator, the pressure should not drop very much. It sounds like you tried that already. I assume there are two accumulators. Are they both reading the same pressure drop when the brakes are applied? In order to test the accumulator, the hydraulic line has to be removed or all the pressure has to be drained. I prefer to remove the line. Then install a pressure gauge at the service valve. Most accumulators have a service valve. You might need a special tool to hook up a pressure gauge. You can also drain of some pressure and see if there is any oil in the nitrogen.

Are the brakes working fine? Often a faulty sensor causes the alarm to come on at every brake application. All you have to do then is to replace the sensor.

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