

| Subject: | Re: Head bolts on Air cooleds oil leaks |
| From: | Dan Johnston |
| Date: | Tue, 8 Sep 1998 19:39:14 -0400 |
Actually I cut the tin on a '78, retorqued the heads and pushed it all back together. I used 3M sealer (that yellow snot stuff) on the tin until the next time when I pulled the engine. Then I brazed my cuts. Worked just fine. dan GMBulley@AOL.COM wrote: > VCR50A@prodigy.com ( MICHAEL G BENTHIN), type2@bigkitty.azaccess.com > Subject: Re: tightening head nuts, '78 > Content-Type: text/plain; charset="us-ascii" > > At 4:33 AM -0700 9/3/98, MICHAEL G BENTHIN wrote: > >No one answered my query on oil leak from engine/cylinder connection in my > >78 Westy. So I went ahead and retorqued the lower head nuts while doing > >the seal work. Stopped it on one side, other side still leaqks a bit. > >Anyone know if this is worse than leaving it alone or know if the upper > >nuts can be reached? Would holes have to be cut in the tin? > > Don't know if cutting holes in the tin would work. I would be very wary of > tightening only the lower head bolts. It is possible (though not easy) to > remove the top tin with the engine in the bus and tighten the top bolts too > - that's what I would do. Were the bottom ones really loose? If not, it > suprises me that tightening them would stop the leak. > > When the engine was put together it should have had sealant applied to the > base of the cylinders to prevent leaks. If this was not done, the only > real solution is taking the motor back apart, cleaning the base of the > cylinders and putting the sealant in. This is a lot of work (Probably 8 > hours for someone that knows what they're doing) so if the leak is bearable > I'd just live with it until rebuild time. > > David-- > > You've brought me temporarily out of "sniveling lurker" mode. I am G. Matthew > Bulley, tollerated mostly on the vanagon list, and former VW motorbuilder. I'm > not trying to flame the above writing, but there are a couple of errors in > fact, and you are considering some no-no's. > > DO NOT cut your tin. never. That would be equal to drill holes in a radiator. > even if you plan to weld over it, the tin is made a certain thickness, color, > and dimension for very (German) calculated reason. Don't paint it, undercoat > it, cut it, whatever. > > There is never any "sealant" applyed to the base of the cylinders. Never. the > base of the cylinder is a heat transfer surface--it transfers some of the heat > from the jug to the block. the only thing that should be there is a very thin > metal gasket, which deforms slightly on torque, and seals and case to cylinder > imperfections. Your builder may have neglected to put these in. The only > remedy is to disasssemble, and insert them. > > DO NOT worry about your upper head bolts. They never get re-torqued, NEVER. > They are about 1/3 shorter, and are on the "cool" side (the top) of the motor, > thus they don't stretch like the lowers. You torque them on assembly, and > that's it. The lower head bolts on the other hand, are on the "hot" side, are > quite a bit longer, and thus stretch. They are to be retorqued every other > valve adjustment, or at least every 20k. NEVER torque above the spec for your > engine as you can hear a sound that will live in your mind forever, the sound > of a case stud popping out of the case. POING! If your torque is correct and > EVEN around the engine, and you still have this leak, disassembly is the only > option. > > HOWEVER: I have (in a hundred or so motors) never seen a leak at the base of > the cylinder that was even worth worrying about. It sounds more like you have > a push-rod tube leak, which is much more common, spills a lot more oil, and > much easier to fix. > > See you at BUGGOUT in Manassas. Stop by, have a free Diet Coke, and see our > 1976 "silent" bus (for sale) Its's marigold Yellow, and has a blue side tent. > Good Luck. > > G. Matthew Bulley > cary, nc > 1982 White Westy > 1985 Jetta Turbo Diesel > 1976 "silent" bus (soon to be former owner) > .
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