The Grizzly G0678 mill has been a good mill, but from the very first day of ownership the oil lines have always had a slow leak. After the mill sat for a week or so, one side of the oil system would always drain down into the drip pan so it would take several pumps from the oiler to get the system full and flowing again. The DRO installation was coming, so it was time to get this annoyance fixed.
I decided to replace all the plastic tubing and used clear tubing because it's easy to see the location of the oil in the system. I bought all these items from a vendor in China via Ebay.
Replacement Parts Specifications:
- Clear Tubing 4mm OD (5/32") 2.5mm ID
- Brass Compression Insert Hose Fitting 2.5mm ID
- Brass Compression Sleeve Fitting for 4mm OD Tubing
Here's a close-up shot of how the parts fit together. First the OEM nut is pushed onto the hose, followed by the sleeve and then the insert goes inside the hose. When you tighten the nut inside one of the fittings, the insert and the sleeve will crimp together and provide the oil seal against the fitting.
A shot of the mill with the table removed. The pump has two outputs: The output on the left has a somewhat circuitous route, leaving the pump for the other side of the knee, then entering a splitter were one line oils the dovetail way on that side while the other line returns to oil the pump side way.
The right output of the pump feeds a splitter which then feeds two lines that oil both ways of the X axis (table). The oil lines go through the casting and end right at the oil pathways cut into the top of the ways. Excess oil from each X axis way goes down through a hole to oil one of the Y axis ways (saddle).
On this mill, the screw nuts are not lubricated with the oil pump. You are expected to regular apply grease to the screws. I use Superlube grease which doesn't seem to dry out and coats the screws well.
Some of the oil fittings aren't of the greatest quality, but usually if you seat the line a few times you can get them to stop leaking. One of the splitters, however, was enough of a problem that I just replaced it. I couldn't source an exact replacement, so I settled for the one shown above. It uses the same size oil line, but it's a bit bigger than the factory splitter. It has never leaked a drop.
Since it's so simple to do with the one-shot oiler, I like to keep the ways well oiled to keep rust at bay. It's definitely nicer to have the oil going onto the ways than draining down into the drip pan when I'm not in the shop.
For way lubrication, I use Mobil Vactra Oil No.2 way oil in the one-shot oiler.