LOW LUBE PRESSURE alarm

[CORBIN92087]

I have a 2005 HAAS VF-2 and the last week or so I've consistantly been getting this "low lube pressure" alarm. So I go around the machine and the PSI on the lube dial is down at zero. I then did what the alarm message told me to do, check the connector on the side of the cabinet and make sure the lines arent blocked, and still cant seem to build up any pressure.

Any suggestions???

[Kool Parts]

Ok..lube alarm comes on and tank is dry. But no pressure on dial?
First I don't think there is any pressure unless it is pumping (small window of time) So you may not be looking at it when it is pumping.
But if its pumping dry that quickly then its on for too long at a time. I "think" there is a way to change that.
Gary

[CORBIN92087]

Thanks for the reply Gary.. No the tank is not empty.. it is full to the max it can be. Ill be machining for a good couple hours then out of no where it will throw out that alarm, and I go back and check it and it is at zero pressure.

[Pondo]

It's going to read 0 if it's not pumping at that time, it is not always on. There should be a plunger sticking up on the top of the oil tank. Pull it up and release a couple times. The pressure should rise, then drop slowly. If you ran the system without oil there may be an air bubble in it. Pump it up until the plunger drops slowly, it may take 5-10 pumps. If it will not hold enough pressure to make the plunger drop slowly, then you probably have a leak in the system somewhere.

[fuzzyracing1967]

This same thing happens to are vf-4, but only during long stretches of hot weather,it sits in a cornor of the building and doesn't realy get much air movment around it. So we have got into the habit of putting thicker oil in for the summer, then it is fine.Could be that simple.

[Haas__man]

The unit should pump approx every 32 minutes of run time i.e when the spindle is running. To check that the unit is running - start the spindle at low RPM. Get a flashlight and shine into the lube tank. You are looking for a small motor shaft that hangs from the top of the tank - it will be quite difficult to see - when the machine spindle is running, the motor shaft should also be turning very slowely (maybe one full revolution in 10 seconds or so).
If this is not turning during spindle operation then you either have no power to the unit or you have a faulty unit.
If you pull up the priming handle - hold it for ten seconds or so - then let go, you should get pressure show on the gauge that will slowly go down to zero pressure over between five and ten minutes.
If you are getting pressure for a very short time - then the pressure drops down to zero then you have a break in a lube line somewhere on the machine.
If you are getting no pressure at all then either the pump could have failed - or it could be blocked. Remove the sump containing the oil. you will see an aluminium filter housing inside. unscrew the bottom and make sure the filter is clean. Also you will find a suction filter in the unit - it is the lowest part of the lube unit once you have the sump removed - check and clean this also.

Hope this helps

[haastec]

Also, if the pump is working and the system holds pressure, it could be a bad pressure switch. Prime the pump so the system has pressure and check diagnostics to see if the machine registers pressure or not. If it does not register, jumper the switch and check diagnostics again. Replace pressure switch if needed.

Good luck.