Oil lines

[Ruton]

I see there is a lot of oil line related issues right now and I seem to have one of my own. There is a leak on one of the lines that causes it to create a small pool in the middle engine section before getting to the cylinders. I can also see what I think is a lack of oil in one of the lines sometimes when I am idling. It is usually one of the outer lines. Is it a leak in the check valves causing this or air in the lines? Has anyone rebuilt the lines or, and I know this is a long shot but know where to get some new lines? I've checked ebay and can only find a few used lines. I've also read something about a way to make the oil run through the pump faster, would this work to keep the line with oil and does my T250 have this lever somewhere?

[Fritz500]

I suffered similar problems with my T500. A little pool of oil formed after a few days and there were lots of air bubbles in the section of oil line after the splitter (only to the left cylinder).

You can't buy new oil lines but sometimes old ones (still in the original packaging) pop up on eBay, but don't hold your breath.

The banjo fittings are supposedly not rebuildable...not true. I pulled mine to bits and inspected the spring, ball and seat and found no issues.

I found the section of oil line (beneath the slip-on retaining ring) that fits over the barbed end of the banjo fitting was cracked and seemed to be the main cause of the leak. I haven't decided how to repair that. I'm soaking the damaged end in mineral spirits to wash out any remaining oil then I'll reassemble it with either epoxy or silicon sealer.

Cheers

[jabcb]

The T250/T350 oil lines are NLA.
NOS lines still can be found but they are pricey.

The lines can develop a leak at the one-to-two line junction block.
It occurs on the two-line side between the two lines.
This can be cleaned & sealed.

You may be able to get the check valves to work correctly.
There are some posts about cleaning & flushing the lines.

New replacement check valves are available via eBay.
So far I haven't seen any posts about how well they work.

The plastic washers for the banjo bolts are NLA.
Suzuki provides aluminum crush washers when you order washers.
Leaks often develop at the old plastic washers.
Stat-o-seal washers are a popular replacement that are cheaper & better than the aluminum crush washers.

[Cliff]

Don't forget to remove and clean out the oil tank! Over time a small amount to dust/dirt/crud will get into the tank. When it works it's way through the system it will hold the check valves open causing air bubbles!

[Vintageman]

If you are pooling oil on engine line has failed crack... loose seams 1-2. Unless it is loose at pump outlet leaking between banjo and pump for example. If the bolt is loose it's probably is leaking. If leaking back there you surely will get some air too. So check that bolt for loose.

I have had OK luck with used lines on twins(what option do you have).

If you suck on the check valve end you feel it resist and then crack open... vibrates as it flows its OK. If it take a little suction (~3psi) then check valve working. Next fill lines and hang them up to see if lines hold oil or leaks out of check valve etc over time. Lines still good but engine will fill with oil if it sets a while and smoke until its all gone. Can cause heavy carbon and frequent decarbon of engine.

I am going through hell on my gt550 ... check valves leak a little and have for while. bought used and those leak worse! Changed a couple check valves, but still have few that leak. It is not always easy to get the metal barrel off .

The guy on ebay selling new check valves is getting less attractive to me unless I have a better method. Any body have good technique to remove old Check valves without ruining things?

Order two more sets of used lines. Hope OK

On eBay Check "misc parts" or "bolts" some guys are throwing these oil lines with misc. parts bundle and cheaper usually.

[yeadon_m]

I did manage to remove, repair and refit a few valves but I didn't achieve a neat result. Didn't leak though! A better way maybe to gently heat the plastic to make removal easier. I think they were originally forced on with heat and pressure from the collar?
Mike

[Fritz500]

Don't forget to remove and clean out the oil tank! Over time a small amount to dust/dirt/crud will get into the tank. When it works it's way through the system it will hold the check valves open causing air bubbles!

Very good point. My oil tank had a lot of crud and the filter was damaged.



Cheers

[Coyote]

Correct me if I'm wrong. It seems to me that Suzuki could have avoided all those delicate check valves at the banjo ends by using just a single check valve between the oil tank and pump. Would that not be a viable option for trashed valves at the banjos?
Never mind. I just realized why that won't work. Could have worked with a re-design of the pump - giving it the ability to 'pull' as well as 'push'.

[tz375]

The check valves are really to stop crankcase pressure from forcing mixture up the lines. In theory it also stops the oil from seeping out and filling the crankcases.

Interestingly, the first GT750 pumps had three plungers. One sucked oil from the tank and the other two fed the crank and intakes. That was one of many parts that changed in mid 72.