Air in oil lines - please help

[flyingblind]

Gentlemen,
I've got air in my left side oil lines, after the 1-into-2 junction. I know this is a well-known problem. I've read most of the threads already. (I've been researching this for a few days and this forum is by far the best informed.)

What I've learned so far:
- likely a bad check-valve is allowing pressure to push air back into the lines.
- I could have a bad o-ring in the oil pump -- though I'm thinking not, since the right side line is working fine
- someone sells after-market check valves on eBay but they cost a LOT
- there is, somewhere, an oil-bleed bolt on the pump that could need to be tightened.
- the crush washers above and below the banjo bolts could be leaking air in.
- I could even have a bad union bolt, though that's unlikely.

I'm really frustrated. I've had the line off once already and blown compressed air through it. I found a pin-hole and repaired it. I'm going to take the friggin lines off again and clean it out with some starting fluid (or should I use alcohol? wd40?), in hopes that the check-valve is just stuck open and maybe I can get it un-stuck.

ANY help would be useful. I have 2 specific questions, though:
(A) what are the original washers at the banjo bolts supposed to be made of? One parts book says it's 09168-06002 (Gasket 6.5x12.1.5) and another on-line parts fiche says it's #09168-06004 "Gasket 6.2x11x1.2" but neither one mentions the material. Should it be nylon, or metal, or fiber?

and (B) where is the "bleed" screw or bolt? What should I be looking for in adjusting it?

Thanks for any help you can offer.

[pearljam724]

Gentlemen,
I've got air in my left side oil lines, after the 1-into-2 junction. I know this is a well-known problem. I've read most of the threads already. (I've been researching this for a few days and this forum is by far the best informed.)

What I've learned so far:
- likely a bad check-valve is allowing pressure to push air back into the lines.
- I could have a bad o-ring in the oil pump -- though I'm thinking not, since the right side line is working fine
- someone sells after-market check valves on eBay but they cost a LOT
- there is, somewhere, an oil-bleed bolt on the pump that could need to be tightened.
- the crush washers above and below the banjo bolts could be leaking air in.
- I could even have a bad union bolt, though that's unlikely.

I'm really frustrated. I've had the line off once already and blown compressed air through it. I found a pin-hole and repaired it. I'm going to take the friggin lines off again and clean it out with some starting fluid (or should I use alcohol? wd40?), in hopes that the check-valve is just stuck open and maybe I can get it un-stuck.

ANY help would be useful. I have 2 specific questions, though:
(A) what are the original washers at the banjo bolts supposed to be made of? One parts book says it's 09168-06002 (Gasket 6.5x12.1.5) and another on-line parts fiche says it's #09168-06004 "Gasket 6.2x11x1.2" but neither one mentions the material. Should it be nylon, or metal, or fiber?

and (B) where is the "bleed" screw or bolt? What should I be looking for in adjusting it?

Thanks for any help you can offer.

Washers are nylon. Bleed screw is located on the head of the pump. It should be the only screw on the side. It's unlikely, that the bleeder needs tightened causing air to enter. It's more likely that you need to learn how to bleed air out of the system using that bleeder. Crack the bleeder screw open until a drip of oil comes out. Tighten the screw. Start the bike. Hold pump wide open for a few seconds, then release. Open the bleeder again with the bike running until you see drip of oil. Repeat, until all air is removed. Running the bike, will sometimes remove air alone. If this doesn't work. It may be a check valve or cracked line, octopus. Regardless, you need to inspect all of the octopus seals. If they are somewhat hard, replace them. They can be found at any hardware store. If they harden, air has a chance of entering. Check to see if pump mounting screws could use a little turn. Be careful not to over torque though, as the octopus could crack. Check for cracks in all places. It's a bad idea using compressed air. That method can easily damage the check valve spring/ball. Alcohol is fine to clean lines.

[jabcb]

The original washers were some sort of plastic, perhaps nylon as pearljam724 indicated.
Suzuki now sells aluminum crush washers, but I don't think there are even worth trying.

Stat-o-seal washers are a popular alternative.
Are available at McMaster's at reasonable prices.
http://www.mcmaster.com/#93786a125

Check the junction block on the 2-line side. Seems pretty common for a small leak to develop between the two lines.

Bloop2 sells a kit with the pump rebuild parts on eBay.
If you rebuild the pump, pay particular attention to the bleed screw, which has reverse threads.

[flyingblind]

Gentlemen,
Thanks very much for replying and for the helpful advice. I have had to tend to other business but I'm going to pull the left side oil lines this week and check (a) the check valves, (b) the 2-into-1 junction, and (c) the pump air bleed screw as mentioned, in that order. My right side lines are working fine, so I'm fairly confident it's not the pump... Still, I do notice that as the pump pushes oil into the lines it seems to do so in spurts, not a steady stream.

Thanks again!

Adam
1973 T500

[Cliff]

I would remove the oil tank and clean it out to start with. Read my post "viewtopic.php?f=2&t=10469". I was having problems with air bubbles too but after I cleaned out the tank, no more bubbles!

[Coyote]

Still, I do notice that as the pump pushes oil into the lines it seems to do so in spurts, not a steady stream.

Yup. That's how they work. They do not put out a steady stream. So that's one less thing to worry about

[Vintageman]

In the twins I have had this problem exactly as you say. I bought a used line and same problem.

And in most case you run the pump the line works fine (you need clean tank,good pump, good seal on banjo's yadayada) and fills in pulses as you see. But once the engine runs it is as if the engines vacuum causes the air entry.

I suppose the line could have hole, maybe at the 1-2 split, but I don't see one.

I had once changed check valve(s?) and fixed problem. When I did I am sure it did not fail the "fill with oil and hang leak down test"... but not 100% sure anymore for did not treat this as a documented lab experiment.

I have new Kawasaki check valves that came in yesterday.... now it just getting the time to try. My plan is to take my spare left and right lines and change so all four matching Chk Valves... I only have these two spare ... nervous about ff'ng up.

I think I could bugger up the 1 - 2 spilt with JB Weld if it still gets air, but one thing at a time

[Vintageman]

This time my bubbles was caused air getting into the pump I suppose for put rebuild kit now OK.

As I took it a part found the 17mm nut that accesses the pump piston was finger loose and the O-ring looked fatigue. But, I changed everything so who knows exactly.

Like someone else said, it can be anything from supply tank banjo washers, pump seals/o rings, bad lines, bad check valves…