Our 980G has just started to lose brake holding pressure. We don't think it is the disks because the were just replaced 2-3 thousand hours ago. Also it feels like the peddle is soft or doesnt have as much resistance.
980GII? Serial number? This is what Ide do for an AXG prefix. First check oil level. Check filters if you like. Check brake pressure .. Should be 625psi +- 12psi. http://i127.photobucket.com/albums/p124/rosspec/g00476720.jpg If the pressure is low then bleed. Loosen fitting #2. http://i127.photobucket.com/albums/p124/rosspec/g00835023.gif If the pressure is spec then drops off fast, Check Acumulator's. Brake charge & pilot share a pump and its common to lose brake pressure & Pilot if the machine has been recently serviced and sat for a long time. Also low oil level can screw everything up and once air gets in it wont self bleed.
To check the accumulator charge, run the machine for a minute or two. Shut it off and then turn the key back on. Pump the brake pedal until the low brake light comes on. It should take 5-7 pumps. If so the accumulators are OK. Also check the axle oil levels. if one is way overfull the you have a leak, normally a piston seal but could be a cracked tube. what oil is in the axles?
As above. Serial Number..? What make & viscosity of oil in the axles..? Also: What type of work is it doing..? Does it have an axle oil cooler fitted..? Is the "loss of brake holding pessure" the same on both the left & right brake pedals..? Any instances of TC overheating..?
Thx for all the replies. We are just getting back from the weekend and we are going to try you're suggestions and I will post the results
Remember to post the Serial Number of the machine if nothing else. For those of us who have access to Cat systems and diagnostics information it helps us to help YOU ............