Bit of a left field question..

After a couple of hours of spirited riding to Morwell and back (In high forty degree temp), i noticed an oil leak had developed on my shovel, suseed it out, it is leaking from the oil pressure gauge (V-twin brand, "liquid filled", screws into the top of the oil pump)

The oil (or whatever it is?) inside the gauge/ facia was leaking out. Took it off  today, turns out there's a bung on the side of the gauge housing. Looks like a fairly straight forward operation, drain, clean, refill and reseal, maybe using a little sealant.

My question is, what is the liquid in liquid filled gauges?

I was planning on filling up with sewing machine oil as the liquid inside is oily  and fairly light, Just thought I'd put it out there for any thoughts / suggestions?

glysirin mate you can eat the stuff if you want too, head down to the local supermarket, comes in small bottles cheap as chips!!, be sure to leave a bubble  in the gauge as this stuff expands with heat, alot of the gauges being mass produced slipp past quality control hence that why the 40deg popped the plug... rember dont fill it all the way ...and dont use oil

At least your seems to be working Shoveltrouble. Went for a ride last weekend and all was fine until i looked down and had NO oil pressure. Now the thing is a bit temperamental at the best of times but i thought OH SHIT. Was only around the corner from a mates so after a few beers and scratching of the head i started her up and was working again. Although i got home ok the gauge began dropping again after about 15 mins at 110km on the Highway???? Hope it is just a dodgy gauge!!

Pressure can drop as far as 6lb at idle, at best it will be around 35lb at 2000rpm. The factory finds between 12-35 acceptable at 2000rpm. Post 79 pumps are supposed to improve flow about 30%. Areas to check are 1- Tappet screen, 2- Oil Gauge, 3-Oil filter and feed and return line to oil tank. These 3 areas need to be checked and cleaned, debris may cause enough of a blockage that flow is slowed down or interrupted altogether, or give you a false reading at the gauge if this is where the blockage is. The main area to worry about is excessive noise coming from your top end. This is a sure sign the oil is not getting through. Heat of course can also create a low pressure situation, and if you are going to be riding in 30+ degrees most of the time changing to 60 wt could be recommended.

Yeah Don it was a bloody hot day and when bike was cold about 30lb but it gradually dropped to nothing on the way out but on the way home dopped gradually to about 8 or 9 lb. Will need to check a few things i think but it was purring along with no strange noises so all good i hope. Cheers.

Oh yeah...am currently running a straight 50wt but may look at the 60wt...just bloody difficult to get your hands on it i am finding.

Hi Hutch82,
Another thing you might look at is an oil cooler. I never used one on my Shovel when in Sydney, (lived in the northern beaches. Avalon.)
But if you are finding it hard to find 60wt it could help. It adds a bit of oil to the total, and when cold weather hits, just put a cover over it to stop the airflow.
Regards,
Cris

Yeah Cris, have one of those mate so i am hoping it is just the guage...too bloody hot to ride at the moment anyway so will check it out when i get a minute.
Cheers mate.