Oil Leak.

[Bobb]

My ST has a small oil leak at the rear of the engine that will "dirty up" the backside, but never enough to drip. I recently changed the oil and spent some time cleaning it up. Shift shaft area, oil filter base, hose boss, and as far "up" as I could get. Here's the question....it is weeping and I haven't started the bike yet or moved it off the centerstand. Fresh, clean 5w-40 Rotella oil drool. What component lies below the oil level that could be the cause? It's NOT the shift shaft, gotta be something higher, but not above the oil level! Oil level right now at the exact top line in the sight glass. It's also spotless around the filter. Clutch fluid not going down at all, clean and reservoir full. Speedo sensor or clutch slave??

 

[SupraSabre]

Can you get a picture of the area where you see the fresh oil?

 

[Bobb]

The bike has yet to have a valve clearance check. It's an '04 with now 36K on the odo, and the prior owner did not bother to do it. It's on my to-do list. Since I cleaned and wiped the oil drool off though, and have not started it yet, the drool went from "used, darker oil" to the brand new Rotella.........so I'd assume the leak is BELOW the level of the oil in the sump......it's worth a check though!

 

[Bobb]

Suprasabre.................Will do tonight!

 

[Bobb]

Pics of the belly....

 

[SupraSabre]

Looks a little wet, and I can see where it looks like oil is coming down those hoses, which I would think could be a valve cover gasket leak. You might want to run it for a short period and see if it's an obvious leak.

 

[DavidR8]

A trick I've used to find leaks is to dust the area with talcum powder. I have plastic container with small holes in the top. I quickly squeeze the container and out comes a light dusting of powder. Keep dusting till the area is uniformly covered.

The source of the leak will soon wet the powder.


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[Bobb]

Looks a little wet, and I can see where it looks like oil is coming down those hoses, which I would think could be a valve cover gasket leak. You might want to run it for a short period and see if it's an obvious leak.

I'll give that a go, but.......remember that prior to the oil change, the weep was obviously "darker, used oil", whereas after I changed it......and did NOT run it yet, there was a weep of new clean oil. I'm going to assume it's below the oil level in the sump......leaning towards the speedo sensor o-ring. Need to clean it better and look closer.

 

[Bobb]

A trick I’ve used to find leaks is to dust the area with talcum powder. I have plastic container with small holes in the top. I quickly squeeze the container and out comes a light dusting of powder. Keep dusting till the area is uniformly covered.

The source of the leak will soon wet the powder.




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Thank-you. I've used that method on some prior bikes and agree it works great. Especially in difficult to locate leaks.

 

[Bobb]

I "think" I've discovered the leak originating from the u-joint / boot. Quite possibly the seal for the output shaft. There may be others, but have traced some oil towards that area. Question I have......does anyone know if the rear fuel tank removal will give me better access to that "area"? I might as well change all of the seals/ o-rings on the rear engine cover. There aren't that many. Any procedural recommendations? Looks like the swingarm, shock and tank removal might let me get there.

 

[SupraSabre]

Interesting, It never even occurred to me for the output shaft to leak! 4:

If you are removing all of that (which I have never done before...) be sure to replace the starter o-ring as well!

Also, the o-ring between the oilcooler and the engine is one I have yet to find anywhere in the Honda Parts books!

When I had my 2005, I had bought a spare engine to replace mine @ 200K. I was going to replace all the seals and o-rings. I never saw 200K, I sold the bike to my son, who is still riding it, but only puts a few thousand a year on it.

Good luck and keep us posted.... with pictures too!

 

[Igofar]

No need to remove the lower fuel cell. You can search the forum for U-Joint replacement and find your answers there.
You'll need to remove the rear wheel, mufflers, side step, rear shock, driveshaft housing, etc.
You'll also want to check your swingarm bearings while your in there.
Be very careful and follow the SM to the letter when replacing the swingarm and tightening everything back to spec.
Depending on what model you have, you may have to deal with shims too.
I responded to this thread and pointed out that it may be the output shaft seal, but for some reason I couldn't post it from my phone.
Sorry for the delay in my response.

 

[Bobb]

Thanks Guys!
I plan on doing this within the next few weeks on again / off again. I'll try to post pics once I get to the area in question. Have to mix it in with my normal "life" responsibilities.

 

[stefan7n]

Hi All. I just picked up my ST1300 last week. Due to family commitments slowly working the full service. So far oil and filter spark plugs air filter and final drive oil. Next job is full flush of the coolant systems the expansion is empty, annoying. On closer inspection the back of the engine block is covered in thick black oil similar to the picture above but must have been leaking for a longer period. The previous owner failed to mention. Nevermind.

I’ve yet to take the plastics off but will do shortly when I flush the coolant system. I’ve inspected the half moon gaskets I can see and it isn’t obviously leaking. I do need to inspect the rear ones too though. I can see oil like the above pic as mentioned but also done the rear most cylinders on both sides. I guess the oil could run that far?

Relative newbie to fixing bikes so welcome any advise and apologies for any ignorance.

 

[BakerBoy]

Welcome stefan. That oily appearing black residue can also be from coolant or years and years of road grime. Unless there's a wet drip hanging from something, I'd suggest a cleaning of the area, then take it for a ride and inspect again following the ride.

 

[Bikeric]

Hi All. I just picked up my ST1300 last week. Due to family commitments slowly working the full service. So far oil and filter spark plugs air filter and final drive oil. Next job is full flush of the coolant systems the expansion is empty, annoying. On closer inspection the back of the engine block is covered in thick black oil similar to the picture above but must have been leaking for a longer period. The previous owner failed to mention. Nevermind.

I’ve yet to take the plastics off but will do shortly when I flush the coolant system. I’ve inspected the half moon gaskets I can see and it isn’t obviously leaking. I do need to inspect the rear ones too though. I can see oil like the above pic as mentioned but also done the rear most cylinders on both sides. I guess the oil could run that far?

Relative newbie to fixing bikes so welcome any advise and apologies for any ignorance.

Welcome to the forum from Cornwall UK! Oil gets blown about all over the place when you are riding and often leaks from somewhere else on the bike. When you get the plastics off it, clean everything, then start her up and see if there are any obvious leaks. May just be old crud from the previous owner......

 

[Upt' North]

Hi All. I just picked up my ST1300 last week. Due to family commitments slowly working the full service. So far oil and filter spark plugs air filter and final drive oil. Next job is full flush of the coolant systems the expansion is empty, annoying. On closer inspection the back of the engine block is covered in thick black oil similar to the picture above but must have been leaking for a longer period. The previous owner failed to mention. Nevermind.

I’ve yet to take the plastics off but will do shortly when I flush the coolant system. I’ve inspected the half moon gaskets I can see and it isn’t obviously leaking. I do need to inspect the rear ones too though. I can see oil like the above pic as mentioned but also done the rear most cylinders on both sides. I guess the oil could run that far?

Relative newbie to fixing bikes so welcome any advise and apologies for any ignorance.

Welcome Stefan from Northumberland UK.
I had some panels off my 11 earlier this year and the 1 side was coated with sticky black oil and crud. Strange thing is, the bike uses NO oil. NO OIL?
I wiped it off and put it back together. I'll check it again in another 60,000 miles.
Enjoy.
Upt'North.

 

[stefan7n]

Wow. Thanks everyone for the thoughts already. I’ve been having a tinker today. I was able to get the fairing off the left side but will need some more time to get the right side off. Who ever has had it off didn’t copper grease the bolts before putting it back together. I’ll need to order some new bolts and drill one or two out.

I did manage to get pictures see attached. I’m hoping it’s just a few years of crud and nothing more sinister. Once all the panels are off a damn good clean is in order. Then I need to ride and inspect as you’ve all suggested.

Also I managed to discover the coolant expansion tank wasn’t empty. Just lacking any colour and at the low mark. Topped up temporarily with some pink readymix but will replace with all clean once I get the panels off. Think I’ll pull the radiator and give it a special flush and clean.

Thanks for the advice.

Stefan.

 

[stefan7n]

Should probably mention it’s a 2010 model with 48k miles on the clock. Reasonable service history.

 

[BakerBoy]

First thought on seeing those pics: I'd first look for oil seepage from the valve cover.

There is an oil drain hole near each exhaust header connection--each hole allows oil to drain out of each spark plug well. The spark plug well can accumulate oil if the valve cover gasket is not seated correctly when the valve cover is reinstalled (or if the valve cover bolts aren't seated and torqued correctly). Caution: the valve cover bolts are easily cross threaded, can be mis-threaded into a cranny, and are known to break with more than specified torque. Do NOT overtorque them to 'see if the valve cover gasket is tight enough'.