Topic: Found The Oil Leak

[jx25]

So I replaced the head gasket on my cb750k8 over the winter months and all the other gaskets above that, but for some reason I didn't bother to flip the heavy motor over and inspect the bottom half.  Got everything back together and noticed that after sitting over night, it had left a pretty good sized oil stain on the cardboard underneath it.  So I tightened up the drain plug and thought problem solved.  Well I was wrong, I started her up and played around with the carbs and noticed the oil stain had grown.  So I got a mirror and discovered a crack.  So I dropped the oil pan and found this.....
Im planning on trying to weld it up but I'm not sure it's gonna work......

Can't do much on this side

can probably fill this side up

hopefully can get in there and fill this side up


Could this be from overtorqueing the drain plug??

Otherwise CycleX is about an hour north of me and this weekend I'll have to take a ride up there and get a new oil pan

[fuzzybutt]

do yourself a favor and prevent headaches, get the new pan. either welding or using some kind of epoxy (like jb weld) may  or may not work as i imagine that it might be difficult to get ALL the oil out of the metal around the crack and that would prevent the patch from holding well.

[martino1972]

+1...
Due to the fact that you will have to use the drain plug again to drain oil,I'd would get a different pan...
If it was at a spot where you could leave it alone after the fix,you could JB weld it,but I doubt it would be wise to do it here....

[bryanj]

Caused by overtightening on a repeatedly used sealing washer Only real cure is another pan

[mystic_1]

+2 you'll spend less on a new pan then you will in time and aggravation in trying to fix the old one.

mystic_1

[ugmold]

I had the same problem on 78 550k, the JB Weld slowed it down, actually worked fine on the side crack, but the face where the drain plug goes leaks. I tried a copper washer, but still leaks.
-ug

[Sporkfly]

I'd go with the new pan.

But just to be the devil's advocate! You could completely fill the crack on all sides (even over the threads) and retap the hole (through the JB, it says right on the package you can tap the stuff.) On the mating surface for the washer, sand it smooth and flush.

Just saying, JB could work if you did proper surface prep and filled in all sides. Again, I'd go with the new pan.

[Frankenkit]

I'm devil's advocate AND a pack-rat.  I'd recommend getting a new one and seeing just how well you can fix the old one. That way, if something bad happens (it'd have to be pretty bad to mess up your sump...) you'll have a spare to slap on until your new order comes in.

[mystic_1]

Because of the way the crack is spread out, if you just squeeze JB Weld down into the crack, the hole will end up being larger than it's supposed to be.  If you go this route you need to find a way of clamping the casting so as to squeeze the crack together as much as possible.  This gives you a better bond with the JB anyway.

A good TIG weldor could probably seal that crack in about 10 seconds, then just run a tap through it and you're good to go.  Much better fix.

mystic_1

[jx25]

What ended up happening is my father took it to work and clamped the threads then tig welded the crack, retapped the threads, then milled the area the drain plug mates with and made that surface flat.  So far I haven't had any problems.  I have yet to get a non-cracked pan.  I also am using a different gasket than the aluminum ones.