523: Lube Pressure Alarm on Mazak VTC-41
The machine has been off for a few months. Today when I brought up the machine I noticed it would only execute one line at time, like it was in single block mode. Checking the alarm screen I seeing an error 523: Lube Pressure Alarm. The oil reservoir was half full so I gave it a quick couple pumps and the alarm cleared. I could definitely feel it building pressure while pumping. It worked for a while but eventually came back. I topped up the reservoir. Same issue. No obvious puddles forming around the machine. No air bubbles in the line from the oiler.
The machine has been off in the past and this is the first time I've encountered this issue. I suspect I may have a cracked oil line, a bad pump or maybe a check valve someplace is leaking. Everytime the alarm triggered it only took two or three pumps to clear the alarm. I'd think if it was gushing I could pump indefinitely without building pressure.
I'm likely going to limp it along tomorrow and see if I can find any leaks. It's possible it may clear itself with more run time. If you've hunted this issue is there anything I should look for first?
Re: 523: Lube Pressure Alarm on Mazak VTC-41
I'm suspecting a leak someplace. I verified the pump motor is running and the pump cam appears to be moving very slowly, as it should. If I pump it up and then come back a few minutes later the pressure has clearly dropped. Now I just need to pump enough oil to see where it's leaking.
Re: 523: Lube Pressure Alarm on Mazak VTC-41
Quote:
Originally Posted by
servtech
If no pools of oil from axis flow valves, then suspect pressure switch.
You could then try blocking off each axis line to isolate the fault.
I blocked off after the pressure switch and confirmed the pump maintained pressure and the switch appears to function correctly. I removed the back panel so I could get a better view. With the Y axis moved full forward it revealed both linear bearings are leaking a lot. I soaked up all the oil in the morning and by noon the drain channels were full with oil draining to the rear of the machine. I suspect the seals are worn out or damaged. I'll need to pull the way covers to get a better look. I'll need to look at the parts diagram on Monday. How hard is it to replace the seals?
Re: 523: Lube Pressure Alarm on Mazak VTC-41
Quote:
Originally Posted by
servtech
I think it more likely the lubricator before the shoe is faulty. The system requires back pressure to maintain pressure, a shoe has too much path to provide back pressure.
Common on the end of a lube line is a "flow popper" that opens on a pressure impulse from the pump allowing a fixed volume of oil to escape. The whole system should maintain pressure throughout the pump off time. Usually on time of 30secs is enough to allow all flow popper valves to open and close then maintain the pressure until the next impulse. The pump off time could be 20-30 minutes.
Your shoe lubricators are the issue.
That makes a lot of sense. Is the shoe lubricator at the shoe, maybe the brass block where the tube connects? Or located at the distribution? I assume I'm looking for a poppet valve of some form.
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Re: 523: Lube Pressure Alarm on Mazak VTC-41
I figured out what I need. I'll pull the size off the units in the morning and get some coming. I'll bet they're gummed up and stuck open. Can they be cleaned? Or is it not worth the effort?
https://www.allworldmachinery.com/itemdetail/105009
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Re: 523: Lube Pressure Alarm on Mazak VTC-41
Quote:
Originally Posted by
servtech
.
Exactly that.
The number on the flow popper indicates the volume of oil per pulse. 5/10/20 etc.
They're not repairable, the diaphragm inside goes bad and either leaks or blocks up.
They screw into a manifold on each axis fed by a common oil circuit pipe. Sometimes, this supply pipe can split and leak.
To test, all pipes from the poppers should be removed and clean paper put under to determine how much oil is being used at each manifold point.
Thanks so much for your help. They turned out to be AJB-1 which crossed to the HJB-1 that I ordered this morning. I ordered enough to replace them all. I'll see how it goes in a few days when the parts arrive.
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Re: 523: Lube Pressure Alarm on Mazak VTC-41
servtech, your suggestion was spot on. I replaced the poppers yesterday morning and so far no more oil pressure issues. After replacement I tested with paper and the flow looked very even. I suspect I have another distribution point someplace in the column so I may need to be proactive and do those poppers also.
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