T350 No oil in left side line

[T3501972]

Hi, I'm hoping I can get some help here. My T350 is not pumping oil on the left hand side line. I have taken the line off, cleaned it out by spraying WD-40 done it, filled it back up with oil, and refitted it. It pumped out the oil in the line, then just has none, or a few bubbles of oil? The right side line is pumping oil. I have cracked the bleeder on top of the oil pump while the motor was running, nothing came out, no oil or air. I'm thinking it could be the oil line check valves on the left side ?

[Vintageman]

Yup, very well could be a bad check valve... I was trying to explain this on my other post about Aftermarket UK check valves when I discussed twins with their oil lines... ya da ya da

[T3501972]

Yep I have decided to replace the check valves, it's all it can be really, the right side oil lne is always full, and the pump is working, the left side oil line has oil up until the junction, where it splits into two, then there is just air and a few oil bubbles. I'm running pre mix fuel, till I get this problem sorted out.

[ConnerVT]

I had a funky thing happen with my T500 oil lines last year. I had a similar issue, where oil would only move up one side of the line (to the cylinder, and not the bearing, can't remember now which side).

I typically prime the lines by removing the lines from the engine, then removing the pump from the engine. I drive the pump with an electric drill, with a huge flat blade bit.

It was strange, as that one bearing line wouldn't fill. I even attached the old line I have (from the original motor), and it did the same thing! I was really confused at that point.

I put a bolt through the cylinder banjo fitting, with a couple of washers, to seal off the cylinder line. Oil then flowed to the bearing banjo fitting. After removing the bolt, both sides now work normally.

Fluids will typically move toward the path of least resistance. I could be the cylinder side doesn't seal as well as the bearing side, there could be a stronger spring in the bearing side, or just that there was air to compress was not enough to show significant oil flow to the bearing side. All I know is that oil now seems to be moving everywhere it is supposed to go.

[Vintageman]

ConnerVT

I have also seen air get by washer and get sucked in. But even when you fix that a bad check valve appears to cause same problem.

In my case the lines did not leak (or at least quickly)

Your case I would say a check valve was stuck open... getting all the oil. Strong argument for check valves break open point being well balanced.

In my case I could see both lines gettng filled by pump - pistons still and I was using a drill with clutch cover off to run pump. But soon as you run engine it would have air just like noted in this post and my UK Check Valve Review post side bar ( I like your idea of removing pump off case and using tach end to run pump)

There can be more than one reason for this air, bad tubing, forward leaking check valve, fitting, washer seal, but now it does seem a check valve can get air sucked into it (or whatever the reason)? Was an elusive problem for a while?

T3501972
In my case premix may not have helped. The line with air was for the crank bearing feed. You want to fix that soon

[T3501972]

Thanks. I am replacing the entire oil line, with a new Suzuki OEM one. I will post up when I get it back together, and if it fixed the problem.

[T3501972]

A new oil line, with new check valves, has fixed the problem. Oil is now flowing evenly with no air bubbles in the line.