What's new
What's new

Slide Lube Alarm - Oil Pressure Sensor

JohnXKennedy

Plastic
Joined
Jun 6, 2017
Hey guys, I have a QT15 which is throwing a slide lube alarm and preventing me from running programs. If I disconnect this sensor (see image) the alarm goes away. The pump motor is running and if I manually pump the lube system it is definitely moving oil.

Does anyone know where to source this sensor? I don't see any manufacturer's part no or labeling.


Thanks!

IMG_20200324_114057.jpg
 
From here, that looks like an automotive 2 wire oil pressure switch. You should be able to check it with an air hose and a continuity tester. If the switch is good chances are you have a way lube hose broken somewhere downstream.
 
Broken lube lines should be noticable, extra oil in coolant, or puddles on the floor.
Many systems with broken lines will still seem work properly because the switch will momentarily operate at the start of the lube cycle.

So the real question is does the switch work (doing it's job) and the pump is not pumping oil?

Manually operating the pump means that it can pump oil,
but there are several things than keep the motor from operating the pump.

1. Worn out clock motor, runs but does not turn the output shaft.
2. Some other worn out component between the motor and pump.

So leave the switch out of the threaded port and run the pump for a half hour or so,
or until more than a small drizzle of oil comes out.

My vote is it's a pump issue and the switch is doing it's job, keeping you from running with no lube.
In my experience, it is 10-20 times the pump and only once a switch, and when the complaint is oil in coolant or on the floor, it is a broken line.

Many times the owner screws a switch into a port with the wrong thread (NPT vs BSPT) and causes more problems to fix later.

Just my 2 cents,
Bill
 
Those things have a manual knob for pumping? My machine has knob you pull for a few extra squirts upon start up. if the sensor is not reading press when you do that then it is definitely a line problem, otherwise you are lucky to have just clock or pump issues, maybe an O ring in the pump? NO juice to clock?
 
Just wanted to follow up to to inform the next guy - Lots of good tips given by other members here, I traced the lines as best I could without getting into the X-axis casting etc and when I did not see excessive way oil anywhere I replaced the motor and then the pump.

I initially suspected the motor but after replacing it and triple checking the new unit was working properly the issue remained. I then moved on to the pump.

I was able to find just the brass pump assembly online and did not have to replace the entire unit. This did the trick - I have way oil pressure and the control is satisfied. Thank you everyone!
 








 
Back
Top