Hey there first time posting here, I have a 963b that is giving me a fit. if I set the brakes wide open and stall out the hydrostat both the left and right drive pressure is in spec, if I slowly bring it up in reverse only it’s around 1000 psi difference, low on the right side I’ve checked case drain rebuilt the servo cylinder and replaced the cylinder hoses and no luck I’m at a loss. Any help would be appreciated. Thanks
A 9BL-prefix machine I assume. This is really our resident Cat track loader specialist's area but I'll start off at least. Hopefully he'll see this and comment. Care to share the actual pressures you measured.? Any prior history of poor performance.? Did you perform any external linkage checks and/or adjustments before starting with your pressure testing.?
Left side forward stall 5300 psi Right side forward stall 5500 psi As far as I know it’s had no previous failures or issues my customer says it happened all of a sudden. I know the left side is a little low in Forward but in reverse the right side doesn’t start to build pressure until the left side hits 2500 psi and when I stall it in reverse the left side is 5500 psi and the right is 4800 psi
Also case drain is 0 psi which I figured because in forward it makes system pressure
In this case the transmission serial number will be useful. There were some changes around the loop flushing valve and high pressure side of things. Can you clarify this point? Motor case drain pressure should be measured with a low pressure gauge, maybe 0-20 psi. Are you saying you get system pressure on the motor case drain in forward?
I measured right side motor case drain with a 0-15 psi gauge and it was 0 psi
My transmission serial number is 8EX03374