The tap is 11mm X 1.5 I just bought one for my '81 project motor and my son's Corrado head swap.
I'm going for the stock bolts, they are more expensive than the 12mm ones (used on my 82) but I haven't seen stud kits. Im sure they're available but probably costly in the 11mm version.
bscutt wrote:The tap is 11mm X 1.5 I just bought one for my '81 project motor and my son's Corrado head swap.
I'm going for the stock bolts, they are more expensive than the 12mm ones (used on my 82) but I haven't seen stud kits. Im sure they're available but probably costly in the 11mm version.
Thanks for the info. I could feel when retorqing the bolts that they were not clamping evenly and sure enough the gasket started to leak and pressurize the cooling system. It was slow at first, I had to add water every few days, but last monday the leak got larger. Chase those threads, folks.
I also use anti-seize compound on the threads, just a light coating. I never used to tap out holes or use anti-seize on my old American V8 and inline 6 rebuilds, but there's a noticeable difference when you do. Just proves I'm not too old to learn new wrenching techniques! Now that's standard operating procedure for me.
In place of a tap, you can take one of the old studs and file/grind a groove across the threads and then use that to clean out the threads. It works quite well and will not remove any metal from the existing threads. The groove helps collect the debris that gets scraped off.
'91 Golf gasser converted to a 12mm pump, M-TDI.
'84 1.6TD Rabbit with a VNT-15 turbo, still setup to run on vegetable oil.
'84 GTI with 1.7TD pistons and intercooled.
2003 TDI wagon
2000 TDI Jetta.
I couldn't get a tap here locally, you start talking VW and metric at the local parts house and their eyes sort of glaze over. What I did was scrub all the bolt holes out with a wire brush and then cleaned the holes out with q tips, paper towels and rags until they came out pretty clean. I hope that is adequate!
VWCaddy wrote:In place of a tap, you can take one of the old studs and file/grind a groove across the threads and then use that to clean out the threads. It works quite well and will not remove any metal from the existing threads. The groove helps collect the debris that gets scraped off.
The problem with using a standard tap is that the tap is designed to cut new threads into an otherwise non-threaded hole. If you run a regular tap through your old threads, you will remove more thread material leaving less to grip the new bolts. There are companies that make thread chasting taps specifically to clean existing threaded holes, but don't cut new threads into the opening. However, I have no clue if these are made in the metric size, or the size specifically needed for this job.
Everybody else lists their cars here - but not me.
You can also ask for a bottoming tap. Just gives you another option. Its used to cut thread right to the bottom of a blind hole. In a pinch I have taken an extra bolt and ground three flutes into it. Sort of making a thread chaser. You almost need a die to run over it so there's no burrs. You might be able to clean it up with a small set of thread files. Its one of the tricks I do 60 miles from no where and costumers screaming for their compressor.