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Graziano Sag 12 oil pressure gauge?

catch22

Aluminum
Joined
Sep 23, 2006
Location
CANADA
Just wondering if anyone can help me out, I have a car oil pressure gauge and was wondering if I could install it on my sag 12 on the transmission oil pump.
And how it was piped into the oil lines.
Thanks Mike
 
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While I'm not sure where you would plumb a pressure gauge into the lathe oil pump I'm going to suggest that it is probably not worth the bother. I think the pressure developed in a lathe headstock would be close to zero and the gauge wouldn't show anything.
 
Sorry I forgot to put in that it's for the transmission oil pump, they pump around 70 psi I think.
 
If there's anything left from TexasTurnado's time - with the imageshack debacle, I'm almost certain he had a picture there. When I tested the pump on the non-12 here, (flexible line replacing the copper hardline) a tee join leading to the gauge on the output side of the pump was all that was used. Vaguely remember it was about 50 or 60lb equivalent.

Again not reliable memory, 1/8 BSPP on the tube nuts???
 
Just wondering if anyone can help me out, I have a car oil pressure gauge and was wondering if I could install it on my sag 12 on the transmission oil pump.
And how it was piped into the oil lines.
Thanks Mike

Mike, I think the obvious place is where the pressure switch is on the oil pump, i.e. fit a tee or whatever fittings are required to fit both a gauge and the pressure switch.

I have seen this done, the gauge was down next to the pressure switch.

In the past I wondered about using flexible tube and putting a gauge up by the "dashboard" alongside the on/off switches.

However, although a gauge would be interesting, I think the pressure switch remains the best thing for safe oil pressure. If the oil pressure is low, something is amiss.

Texas Turnado's thread had some info about the switch thread in the oil pump. TT wrote: "The oil pump is spot faced for the standard BSPP sealing washer (straight or parallel pipe threads need a sealing washer) I think I will make the washer from C110 copper". He made an adapter, male BSPP to female BSPT, to suit a replacement BSPT pressure switch.

If you are taking the oil pump to bits, or in particular taking the cover plate off, there are some important warnings regarding assembly. If you are planning on doing this, let me know and I will dig out the info.

The third photo is the only one I can find showing Texas Turnado's lathe with gauge fitted.


Sag 12 oil pump 01.jpg Sag 12 oil pump 02.jpg Sag 12 oil pressure gauge TT 01.jpg
 
While reading Texas Turnado's epic Sag 12 rebuild posts, I came across this warning/advise. This was after rebuilding the transmission and giving it a run:

-"I discovered another interesting trait - the oil in the electric transmission was slightly below the line on the sight glass, so I added some to bring it up to the line. Lo and behold, the oil pressure when running jumped from 15 to 20 psi to 60+ psi!

When running, the level was also a bit below the line, so I stopped it and added some more to put it higher so it would be on the line when running. This did not seem to raise the pressure more, but it did reduce the variation of pressure while running.


At least on mine, the oil pressure in the trans (I have a full time guage on it) is very sensitive to oil level, so you guys might want to check yours to see if yours is the same.... I think this might be due to the pump taking in bubbles or foam that may be floating on the surface inside the trans, but have not verified that".

Worth remembering though, previously his transmission was damaged and required repair, so low oil pressure could mean something more serious.
 








 
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