We have two Hardinge Conquest T42 lathes, and I am getting to my wit's end with one of them. It is the model with the hydraulic-driven subspindle and live tooling. The machine is "leaking" out of the back of the collet closer. I say "leaking" because the oil is running out of an area that looks like a relief groove. Below is a picture of that groove from the outside. We have had this closer completely apart so both visually and by the drawing, I know that this groove goes straight through to the hollow trough where the hydraulic oil drains into the drain hose. Another image of the drawing below. Here is everything we have tried to fix this issue:
- Remove and clean collet closer and replace all seals
- This machine has a main pump and a gear pump that draws oil through the collet drain hose and circulates it through a radiator.
- Replaced cooling pump with a brand new unit
- Disassembled and cleaned radiator fins and pipes
- We removed the main pump and swapped it to our other T42 and it worked fine on that machine
- Removed all lines from the hydraulic manifold, cleaned all lines and inside manifold
- Drained and cleaned hydraulic tank
- New hydraulic oil
After doing all of this, the pump is quieter but that's all. Our test is using a program that closes the collet for 10 seconds, opens it, closes it for 10 seconds, on repeat mode. This will run for 1.5 hours before the oil start running out of the collet closer "relief groove". This morning I started the machine, let it sit for 2 hours with the hydraulics on but no collet closing. After 2 hours, these are the temps I measured with a laser thermometer:
- cooling gear pump, 105F
- Hydraulic manifold, 119F
- Main pump, 127F
- Hydraulic motor, 165F
- Tank, 120F (viewed on tank thermometer/sight glass)
Started running our collet program, and within 10 minutes it was leaking again. I also notice small air bubbles in the oil in the drain line. This makes me think the heat is the issue, and our other T42 does not get this hot. But we have replaced/verified everything I can think of so I don't know what would be generating the heat.
I have been trying to fix this on and off for almost a year, so any help would be greatly appreciated. Hardinge has been less than helpful and they take forever to respond.
- Remove and clean collet closer and replace all seals
- This machine has a main pump and a gear pump that draws oil through the collet drain hose and circulates it through a radiator.
- Replaced cooling pump with a brand new unit
- Disassembled and cleaned radiator fins and pipes
- We removed the main pump and swapped it to our other T42 and it worked fine on that machine
- Removed all lines from the hydraulic manifold, cleaned all lines and inside manifold
- Drained and cleaned hydraulic tank
- New hydraulic oil
After doing all of this, the pump is quieter but that's all. Our test is using a program that closes the collet for 10 seconds, opens it, closes it for 10 seconds, on repeat mode. This will run for 1.5 hours before the oil start running out of the collet closer "relief groove". This morning I started the machine, let it sit for 2 hours with the hydraulics on but no collet closing. After 2 hours, these are the temps I measured with a laser thermometer:
- cooling gear pump, 105F
- Hydraulic manifold, 119F
- Main pump, 127F
- Hydraulic motor, 165F
- Tank, 120F (viewed on tank thermometer/sight glass)
Started running our collet program, and within 10 minutes it was leaking again. I also notice small air bubbles in the oil in the drain line. This makes me think the heat is the issue, and our other T42 does not get this hot. But we have replaced/verified everything I can think of so I don't know what would be generating the heat.
I have been trying to fix this on and off for almost a year, so any help would be greatly appreciated. Hardinge has been less than helpful and they take forever to respond.
