Cat 980G Serial number-2kr03683 Our cat 980G won’t move in forward or reverse in any gear. Just put new brake accumulators on and also new bearings for the boom/bucket levers. All the other functions work fine and fluids are all good. It feels like a brake issue as you can feel it go into gear and it shows in gear on the indicator. Is it possible for the brakes to be locked up? Parking brake seems to be releasing. One relevant active fault code is 149.05 Anyone any ideas?
The 149 fault code is related to the ride control. Are you sure the park brake is releasing? Is the brake pedal jammed down?
Pedals both seem fine as you can pump them and watch them return. The parking brake moves when you move the lever. Is there any way to see the shoes at all?
what happens when you give it throttle in low gear ? Is parking brake cylinder rod moving when you release the brake?
Nothing happens when you give it throttle in first, but I didn’t jam on it either. The rod looks like it moves when you release the brake as I could see the shiny part
It should actually drive thru the parking brake in 1st forward it might take almost high idle
Ok I read that in the service manual as well about driving through. Just hate to screw anything up
Is there any way for the service brakes to actually lock up. They do mention it in the service manual but don’t go into detail
Driving thru brakes is a safety thing to get it out of the way. I am trying to think or a way to lock wheel brakes can't think of anything but the foot pedals
It happened one other time before this when we first checked the pressure in the accumulators and they were both at 0. Wouldn’t move at first but then it did after a little messing with it
wonder if accumulator charging valve is screwing up??
It could be from cycling all the time with the accumulators down. I’m not sure how long it was ran like that as we bought it this spring and haven’t put too many hours on it yet
since you have a service manual see if it tells you about checking how many brake applications you should get after running machine to build up accumulators shut engine down turn key on and see how many brake applications you get before brake light comes on
Tested that. Get about 7 applications before the brake pressure light comes on. Says 5-7 is good
The park brake actuator chamber can be manually released by turning the rod. Should tell you which way in the Op & Maint manual. Maybe the brake shoes on are sticking inside the drum by rust or being over centre. I think it's unlikely that the wheel brakes are locking on. You could undo a bleed screw in the service brake lines to see if there is residual pressure.
A couple of suggestions. 1. I know you said that the brake pedals return when pressed but try pulling them both upwards from their “rest” position and check if either of them actually move up when you do that. Also make sure that the area under the back side of the "organ pedal" is clear of debris and that the shaft/linkage between the two pedals is completely free. There are a couple of switches in a housing under the LH brake pedal, one of which is for the transmission neutralizer. If that switch is badly adjusted or the pedal is not fully up then the transmission will not engage gear. 2. In your OP you said "It feels like a brake issue as you can feel it go into gear". Do the driveshafts "kick" when the transmission is put into gear.? Try giving it beans in first gear and see what happens.
Here is the wiring for the two switches. The connections to the neutralizer switch are the black and purple wires.
Ok thanks guys I’ll do some more experimenting
A thought how about firing it up release the parking brake leave it in neutral and have someone give it a push to see if brakes are really locked I would stay in machine just in case it rolls
That’s a good idea I was actually thinking about doing that today with another loader.
Going back to your "you can feel it go into gear" comment. The neutralizer only works on the FWD & REV directional clutches, not the speed clutches. So if you engage gear with the neutralizer energized you should still feel somewhat of a jerk as the relevant speed clutch engaged.
can one use the bucket tilt in neutral to see if the wheels are locked solid?
Update on the 980G After some more investigating we found the parking brake shoes were stuck to the drum. Checked the pedals and they were both free for movement. Pushed on machine with another loader and it wouldn’t budge. Had a hard time actually getting the brake drum off until we took it loose from the yoke. Probably gonna do some more stuff on the driveline while the parking brake is apart. Attached are some pics of the drum and shoe. They must’ve got hot! Thanks for all the reply’s everyone hopefully she’ll be moving material again soon.
From those photos it looks like maybe it was operated with the parking brake applied, which theoretically shouldn’t be possible in normal operation. Some investigation required when you get it all back together methinks.