Oil leaking from under Head cap nuts??

OK. I just reassembled the head and everything is groovy... so i thought. Add new oil, crank her up and OMG SHE IDLES GREEEAT.

wait... what's all that smoke?

OH DEAR there is oil FLOWING out from under the far right head cap nuts.

WHY? I see no indication that there should have been any o rings in the area. What in the world did I do wrong? It is so gorgeous out, and I wanna take her for a spin, finally.

trying to keep my cool here, but this is getting really really old.



it's those two cap nuts that you can see in the photo.

 

Re: Now what did i do wrong?

Mlew has informed me that the parts diagram for this bike (I was looking in the service manual) has different part numbers for the outside washers on the head.

Go figure, the only parts I DIDN'T bag seperately by location.

lets see if getting those in the right place solves the problem...

 

Re: Now what did i do wrong?

hmmm, they all seem to be the exact same size... anyone?

 

Re: Oil leaking from under Head cap bolts??

It has nothing to do with size. It's what they're MADE OF.

Those two bolts run through oil galleries; the washers under them should be soft, copper washers (SEALING washers.) Generally it's a good idea to replace them (to prevent leaks.) Remember how those two studs had o-rings when you were reassembling the motor? They need to seal at the top, too.

 

Re: Oil leaking from under Head cap bolts??

ok. thank you very much. I do remember the o-rings. didn't replace them as they looked to be in good shape. Second guessing that now too.

Thank you for your help!

going to grab some copper d@#!3d washers.

 

Re: Oil leaking from under Head cap bolts??

Dude. Seriously???

THIRTY YEAR OLD o-rings "looked fine?" Are you TRYING to blow this puppy up? To save what, $8 if that?

Thirty year old rubber parts that get subjected to high temps get replaced, period. Especially if the HEAD WAS OFF. How many times you wanna do that?

If you didn't replace those o-rings, it's very likely that you're going to start seeing some oil seepage at the head gasket on the right side within about 2000 miles or less of service. When that happens, you'll know why. Hopefully it happens before an oil-starved cam journal gets galled. If it only leaks IN, you won't know the difference until something bad happens. Or it starts oil-fouling the #4 plug.

 

Re: Oil leaking from under Head cap bolts??

actually... no it looks like the guy who said he got it running last time had replaced them much more recently. But hey, if you're freaking out about it, maybe i really should pull it again, and put the new o-rings in? may as well while everything's fresh and still workable?

I don't mean any insult by saying "freaking out", just saying your reaction makes me think i should go ahead and pull the head again, and to replace those rings.

I'd rather that than "blow this puppy up".

 

Re: Oil leaking from under Head cap bolts??

Head gaskets are a one time torque type gasket. Hope you are not planning on trying to re-use it. Just saying if you do you may be in for third trip down that road

 

Re: Oil leaking from under Head cap bolts??

awesome...

Anyone have any advice on how to get thoe little suckrs out easily? Looked like they had real pain in the @$$ potential.

 

Copper washers can be re annealed with heat ( softend ) with heat from a propane torch . Have done it before ,but carn,t remember the exact procedure. If you google " re annealing copper " you will find the info you need ,
cheers, Murray

 

I'm past the copper washer part. Got that covered. How do I pull those "o-rings" from the two bolt holes in the cylinders?

 

with the head off.

If you're reasonably sure that they were not the originals, but replacements that are still pliable and capable of sealing; don't sweat it unless you get some sign they're leaking, like seepage at the head gasket on that side.

 

I know with the head off, but they seemed to be about 1 inch tall and about 1/4 to 1/3 of that was protruding from the top of the head. unless i have the wrong seals in mind. 1st bike, 1st rebuild, no garage, so I'm doing what I can with it.

I just didn't want to end up ripping the exposed part of the seals and then have the rest stuck in there.

they did seem very pliable and fresh, not brittle or easily torn...

we'll see.

 

You do have the wrong something in mind. I was referring to the o-rings; I think you're talking about the dowel pins. I suspect you think they're assemblies; they're two different pieces.

Those two outer bolts have rubber o-rings located in grooves just to the outside of hollow metal dowel pins on their galleries on the cylinder block; that is what I was referring to and hoped you'd replaced. The dowel pins locate the head/cylinder; the rubber o-rings go in the grooves around the dowel pins and seal the passages. You can dig out the o-rings without pulling out the dowel pins.

The hollow bores those bolts pass through, which are sealed at the top by the copper washers and at the bottom by the o-rings, is how the oil gets to the head and cams. A leak at either end can mean upper-end oil starvation. And you can't see a leak at the bottom unless you're lucky and it leaks to the outside.

Hence my concern.

What manual are you using? I might be able to point you to specific diagrams or page numbers.

 

In the gasket set I bought there were two "o-rings" that were longer, like i said about an inch long. They seemed to be the only ones that would fit around those dowel pins.

I am at work now, but when i get in I'll take a pic or two of the replacement rings I am talking about. When I tried to pry the o-rings out from around the dowel pins (very gently) it appeared that they went into the cylinder block down several mm into the cylinder around those dowel pins. I figured maybe they only got replaced when you take the cylinders off.

well, so far, the leak that was under those washers on the top of the head (now stopped properly with copper crush washers) would seem to indicate that a very fair amount of oil is making it up to the head and camshafts, and I will make sure to check for signs of oil on the plug.

oh, and to answer your question, I am using the original manuals with the addendum manuals. So the 1980 xj650 manual, plus the 82 and other later addendum manuals that contain the changes as years went on.