[Vwdiesel] Head gasket problems

[Roger Brown]

On 11/20/2011 9:39 AM, Craig O. wrote:
> Questions to all experienced VW mechanics out there ---
>    I just removed the head off of my 81 PU because of a blown head gasket
> and I had some difficulty with a few things.
> I broke off a bolt in the left side upper radiator hose housing, and in
> addition while I was removing the thermostat housing (in order to drain
> the coolant) I also broke off a bolt.  In both cases there is enough of
> the bolt remaining to possibly get a hold with vice grips.  Is there a
> tip to loosening it prior to trying to turn with vice grips (IE -
> heating etc)?
>
> AND -- many of the head bolt holes are filled with rust and oil sludge.
> Should I use a thread chaser to clean out the holes?  If so, what is the
> thread pitch on the 12mm head bolts?
>
> Final question - should I remove the carbon deposits from the pistons,
> or just leave well enough alone?
>
> Craig
> _______________________________________________


I hit my broken water pump bolts with a propane torch before removing.  Heat until it 
sorts of bubbles up around the threads.  And maybe tap on the ends with a small hammer to 
loosen the threads.  And for reassembly, consider a stainless steel bolt kit and at least 
use some liquid teflon thread sealer on those bolt threads.  I think that will help them 
release easier next time.

Easy thread chaser is to grind a groove across the threads on one of the old head bolts. 
Use that to go in and out of each hole a few times, wire brushing the bolt threads clean 
each time.  I also found that if I sprayed some solvent down each hole then used an air 
gun blowing across the hole (like blowing across a bottle top) would suck each hole clean. 
  If you do this, hold a piece of cardboard beyond the block to catch the spray of dirty 
solvent.

On the carbon, I stumbled across an easy removal technique by accident.  I had sprayed the 
tops of the pistons with some WD40 to prevent rusting since I was not going to be working 
on my engine for a few days.  Came back and popped the hood and apparently the moisture in 
the air from being parked in the driveway had interacted with the WD40 and carbon and it 
bubbled up like paint with stripper.  Just scraped it off with a piece of wood.
-- 

   Roger