Hi everyone, I have a 453 skid loader that I recently purchased. When you start the machine up and try and move it takes a second or two to start working but then has plenty of drive power however the lift Cylinders and tilt cylinder operate up and down slowly and jerk as you're lifting the arms up. Whether the bucket is full or empty doesn't seem to slow it down or speed it up at all. Is there a separate pump for the drive and one for the hydraulics or is it the same pump? I don't know why I would have so much power with the drive motors if the pump is failing. Any information you guys had would be great.
Help Support SkidSteer Forum:
flyerdan
Well-known member
- Joined
- Mar 7, 2009
- Messages
- 983
Looking at a parts book for a 463, it should have the typical Bobcat construction of two variable displacement hydrostatic drive pumps with a gear pump for the hydraulics at the end. They are ganged, and driven together.
It sounds like you might be having a suction leak that's pulling air into the system, that would explain the jerky cylinders for sure. Possibly it might explain the lag in the drive; I would imagine that the rotating groups would smooth out any impulses from air in the system, but I can't say for sure. Hopefully someone more versed in this will chime in.
It sounds like you might be having a suction leak that's pulling air into the system, that would explain the jerky cylinders for sure. Possibly it might explain the lag in the drive; I would imagine that the rotating groups would smooth out any impulses from air in the system, but I can't say for sure. Hopefully someone more versed in this will chime in.
Hotrod1830
Well-known member
- Joined
- Sep 14, 2010
- Messages
- 513
Have you checked the fluid level? They both use the same reservoir, different pumps.
The fluid levels seem to be fine with the dipstick in the back but then there is a black plastic tank under the cab that was low and I filled it up and that seemed to help quite a bit but did not completely solve the problem. If there was a section leak where is the first place to start looking? Could this also be a problem with the Bics safety valve not opening all the way ?
Hotrod1830
Well-known member
- Joined
- Sep 14, 2010
- Messages
- 513
Usually filling to the full mark on the dipstick will suffice. How long did you operate it after filling fluid? You have to run them a little bit to get rid of all the air.
The large suction hose from the pump to the tank is where I would start. make sure the hose clamps are present and tight. Check for cracked hose, soft hose, ect... If no luck, check and tighten ALL hose connections. Leaks will often show up as just that, fluid leaks. any hose connection that is wet or dripping needs attention.
If still no luck. check pressure at the auxillary ports and check charge pressure.
I have the same problem. I've just purchased the machine with 2400 hrs on it. Changed all fluids and filters, last oil filter change was in 2016!. The oil in the chain case and reservoir was all watery white. After changing the oil the problem is still there though. Now between the reservoir and chain case there should be around 16liters of oil but according to the manual the hydraulic system has more oil than that. Is there something I'm missing? After running it warm today I noticed that the hydraulic oil at the dipstick was "bubbling" and white. Is it just clearing out air and old water?
