Yanmar 2010D Head Removal

[yanmar2010d]

All set to remove the head to have it checked out by a machine shop. The thing that got me started was a blown head gasket. I faithfully followed the shop manual and then removed a bunch of other stuff as the head stubbornly held on to the block. The 3 smaller head bolts and the 8 larger bolts are out (with 2 of those being nuts on studs). Intake and exhaust manifolds, injectors, water pump, multiple small bolts, small plate and grounding wire are off the back end of the head. There is nothing that should be holding the head on that I can see. When I attempted to lift off the head, I was only able to lift the front end (breaking the gasket seal) on both sides somewhere between 1/8 to 1/4 inch and eventually got a small gap the whole way back on the (driver's) right side, but the back left holds firm. I put a 1 inch thick piece of rebar on the lip that sticks out on that corner and levered against the loader and can rock the tractor that way, but it does not separate the head from the block. One of the two studs is at that location and if the nut was still on it, I'd expect the head to stay down this well, but it isn't and there is no apparent corrosion. I've been dumping WD-40 down that opening the last couple of days and that hasn't helped (not saying that the stud is the issue, but its proximity to the problem has me suspicious). I'm close to loading the tractor up and hauling it off to a shop just for this, which of course is the thing I was trying to avoid in the first place. Any ideas would be appreciated.

 

[normde2001]

Use PB Blaster, or candle wax and heat, instead of WD-40 and remove the stud.

 

[yanmar2010d]

So... stud need to come out? That was sort of where I imagined this going. Thanks, I'll give it a try and let you know how it goes.

 

[normde2001]

Of course you know to double-nut the stud and turn the bottom nut. you at least need to break the head loose from the stud.

 

[yanmar2010d]

Used wax and heat and maybe that helped, but as soon as the stud came out, the head lifted right off. Thanks so much!

 

[FleetMan]

Don’t forget, a 50/50 mix of ATF and acetone makes a superb solvent for removing stubborn/corroded nuts and or bolts. Every bit as good as Kroil or PB Blaster.

 

[rScotty]

Used wax and heat and maybe that helped, but as soon as the stud came out, the head lifted right off. Thanks so much!

Glad you got it apart. What you are describing is not only unusual - it's common for most engines, particularly high compression engines. Normally if more than one stud is in place you'll end up having to pull the head straight vertical to get it off, and pulling pure vertical isn't easy even without the possibility that you are fighting a stuck head gasket. When taking the head off, the head can't tilt even a liittle or it will bind on the studs just as you saw. The answer is just to pull the studs as you've done.
BTW, I don't ever use a double nut. Use a stud puller. Worth the money....much safer and maintains the stud's thread shape so that head torque is dependable.

Now when you re-assemble, I bet you find it is much easier to get the head started nice and keeping it parallel with the block surface and just slowly slide it down with all the studs in place. I don't know why that is, but I've seem plenty that go together nicely like that. And I've also seen that have to pull that same head off again for some reason it is another real wrestling match to lift it parallel with the studs even though nothing has changed since it slid together so nicely. I've even ended up pulling studs again.
Good on you for taking your time with it.

What did you find on the head and block surface? & how are the valves?
rScotty