What's new
What's new

No.4 Oil Pressure and Flow

ChriS2000

New member
Hey guys, couple questions about the oil system.

My machine is up and running now, and the oil pressure gauge is reading at a shaky 45-50psi. Also, the oil sight glass takes a while to show any movement, and when it does it shows a steady drip at best.

I know that the sight glass isn't supposed to indicate pressure, just that there's oil moving through the headstock. Just curious what a correct indication is supposed to look like.

Bonus question - all the literature I have refers to an oil filter on the back of the headstock, but mine clearly doesn't have one. Did some come without a filter, or was mine removed at some point?
 

Aejgx6

New member
I think its behind a plate on the back of the head stock. Dont confuse the cutting oil pump for the headstock pump. I think there is a very non descriptive maintenance "guide" on vintagemachinery.org

As for preasure I'd run it, but I can be a little abusive to mine.
 

ChriS2000

New member
I think its behind a plate on the back of the head stock. Dont confuse the cutting oil pump for the headstock pump. I think there is a very non descriptive maintenance "guide" on vintagemachinery.org

As for preasure I'd run it, but I can be a little abusive to mine.

My manual has a pretty good picture of what the filter housing looks like and the plumbing for it, the manual also describes a lever that can be turned to clean the filter out. Mine doesn't have anything like that, but my machine does have some other differences like the preselector drum etc.

I'm sure the oil pressure is fine, my main question was about what the activity in the sight glass is supposed to look like. The steady drip that I'm seeing could be an indication of a clog if it's supposed to be a constant stream, etc.
 

johnoder

Moderator
Are they all supposed to have one? Also John, do you have any insight on what you're supposed to see in the sight glass while it's running?


I'll have to plead ignorance. But I do know that CUNOs were on all sorts of machinery - including radial aircraft engines
 

Aejgx6

New member
Dribble is fine. It's just supposed to indicate it's working. Without the filter you may have some problems. Unless you plan to use it daily I wouldn't lose to much sleep over it.
 

4GSR

Active member
If the old lathe has a pressurized oil pump, which most do, you should see oil flowing thru that sight glass. Not dripping, but a flow of oil. If not, something is wrong with the pump. if the pump is operated by a motor outside of the headstock, reverse the direction of the pump. I'm not an expert, my dad used to be the expert in the family on these machines back in the days.
 

ChriS2000

New member
If the old lathe has a pressurized oil pump, which most do, you should see oil flowing thru that sight glass. Not dripping, but a flow of oil. If not, something is wrong with the pump. if the pump is operated by a motor outside of the headstock, reverse the direction of the pump. I'm not an expert, my dad used to be the expert in the family on these machines back in the days.

It does have a pressurized oil system (about 50psi) supplied to the headstock from an external oil pump that's belt driven off of the main motor. The steady drips I'm seeing would definitely indicate some sort of blockage or bypass going on, unless the sight glass is only supposed to show drainback / overflow.
 

johnoder

Moderator
Likely that to get any such system to deliver oil more or less equally here and there (and the flow sight) there has to be METERING devices. Bijur made these in many "flows" and numerous configurations

These METERING PLUGS are great until they get plugged up - which is normal with age. People have likely "cleaned" some of these to work properly, and just as many more were not fixable and were replaced with new

Just for grins - here is a fairly modern (1954) big name lathe that uses NO noticeable metering plugs and relies on the "pump up and flow down" scheme - the reason for all the oil trays and strategically located oil drain holes
 

Attachments

  • Dcp_1088.jpg
    Dcp_1088.jpg
    96.4 KB · Views: 98
  • Dcp_1089.jpg
    Dcp_1089.jpg
    94.3 KB · Views: 90
  • Dcp_1090.jpg
    Dcp_1090.jpg
    91.9 KB · Views: 94
  • Dcp_1091.jpg
    Dcp_1091.jpg
    96.7 KB · Views: 90
  • Dcp_1092.jpg
    Dcp_1092.jpg
    96.6 KB · Views: 93
Last edited:

ChriS2000

New member
Thanks John. As I've been using the lathe more, I've been noticing the flow (which is actually just a steady drip)seems to be increasing. I'm guessing that stuff is clogged up inside, but I think the safer option is to just keep running it vs. attempting some sort of oil system cleaner or taking the headstock apart.

I think I will plumb in some sort of oil system filer on it to start catching some of the junk floating around in it though.
 

john.k

Active member
You need a oil flow diagram.....its quite likely with 50psi pressure the system is piped to bearings direct from the filter,with the sight glass a bypass to indicate oil flow,not actually in the pressure circuit.......If its in the pressure circuit ,it should fill up completely in a few seconds of running,and be of substantial construction with thick glass.
 

ChriS2000

New member
You need a oil flow diagram.....its quite likely with 50psi pressure the system is piped to bearings direct from the filter,with the sight glass a bypass to indicate oil flow,not actually in the pressure circuit.......If its in the pressure circuit ,it should fill up completely in a few seconds of running,and be of substantial construction with thick glass.

It's definitely of substantial construction, the manual does say that the sight glass is intended to indicate flow through the headstock, not pressure. What's bugging me though is that it's just a steady drip-drip-drip and not a "flow". The sight glass never actually fills up, maybe gets to halfway full.

Oil has been changed very recently. It is pretty cold though, around 32 degrees in my shop. Even after running the lathe for an hour or so it's still just the same drip-drip-drip. I wish someone else with an M-1420 could chime in on what they see in theirs. Maybe I'll just call Gahr.
 

calvin b

New member
Chis2000, sir
Hey I've been around a few of them thar 1420's ( even owned one for a bit). Oil pressure of 25-30 pounds is somewhat standard with recommended oil ( mobil dte medium ISO 46 ). The "drip" is also normal til the beasties warm up and then it's a sorta stream. If you have 50 psi your plenty good or maybe it's a tad high due to a blockage.. Iff'n it was mine I'd run it and find something else to worry about.
Stay safe
Calvin B
PS my 1200 (#3) runs just fine at 25 psi.. also it takes about 6 hours to really warm up a swasey.. so unless your planning on running a second shift live with the drip it should come on pretty fast at start up but if it takes longer than usual you may have an issue (but I doubt you ever will have one, them critters are darn near bullet proof)
 

ChriS2000

New member
Chis2000, sir
Hey I've been around a few of them thar 1420's ( even owned one for a bit). Oil pressure of 25-30 pounds is somewhat standard with recommended oil ( mobil dte medium ISO 46 ). The "drip" is also normal til the beasties warm up and then it's a sorta stream. If you have 50 psi your plenty good or maybe it's a tad high due to a blockage.. Iff'n it was mine I'd run it and find something else to worry about.
Stay safe
Calvin B
PS my 1200 (#3) runs just fine at 25 psi.. also it takes about 6 hours to really warm up a swasey.. so unless your planning on running a second shift live with the drip it should come on pretty fast at start up but if it takes longer than usual you may have an issue (but I doubt you ever will have one, them critters are darn near bullet proof)

Hey Calvin,

Good to know, I was hoping someone with some 1420 experience would chime in. Truth be told, most of the time I've been running it has been in pretty cold weather (in an unheated shop) so the sight glass may read differently this summer.

Also I don't think I've ever ran it longer than 2hrs... it's definitely way overkill for my use case, but I'd rather have too much machine than not enough when I need it.
 








 
Top