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The magazine's YouTube Channel generates a lot of questions, and I encourage viewers to join us at these forums.  A current exchange involved a viewer installing a 4.0L Jeep water pump and asking about how to seal the gasket and engine-to-block.  This is worthwhile for our forum community, here is the discussion:


Question from Ben D.:  Did you use Gasgacinch between the water pump gasket and block?  Looooong time ago I remember using RTV. Was it necessary?


My reply:  I like Gasgacinch on a cut paper gasket like the water pump.  RTV can slough and find its way into the radiator tubes and clog.  An even coating of Gasgacinch, on each side of the cut gasket, is wise.  Gasgacinch resists coolant, gear lube, engine oil and other automotive fluids.  It works well around higher temperature castings.  Edelbrock private labels the product for its valve cover and intake manifold gaskets, each a higher heat area of the engine.  (Gasgacinch is not for an exhaust manifold where I would use Permatex Ultra-Copper RTV or Permatex Copper Spray-a-Gasket Hi-Temp sealant.)  Like many other professionals, I have used Gasgacinch in motorcycle engine work.  My recent XR650R Honda project's rocker box to cylinder head seal is one example of a precisely machined, interference fit without a gasket, using only Gasgacinch for that fit.  (There is no factory gasket here, just sealant.)  This is a good discussion for the magazine's forums at: http://forums.4WDmechanix.com.  Join us, Ben!...Moses




I use Gasgacinch on transmission and transfer case cut gaskets, engine oil pan (cork, rubber or composition) gaskets, seal jackets and shells, bolt threads, and many other paper gasket and interference fit locations.  It works well when coated evenly, and Gasgacinch has excellent tacking ability for holding an awkward cut paper or cork gasket in place during installation.  The YouTube video series on the Jeep Cherokee 4.0L cooling system and water pump work is at: http://www.4wdmechanix.com/How-to-Jeep-4.0L-Water-Pump-and-Serpentine-Belt.html.  Gasgacinch is a long time respected sealant and belt dressing, and yes, it can help preserve and quiet belts!



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  • 9 years later...
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Hi, Ahmed (Mighty_mix)...Unless the workshop manual recommends a specific sealant (like with machine fitted crankcase halves), I coat the paper gaskets with Gasgacinch (or the Edelbrock equivalent).  The goal is a smooth, uniform coating without excess.  Gasgacinch dries to a rubber-like substance.  Excess sealant could slough off and find its way to the oil screen.  I make sure the gasket gets an even layer on both sides and follow the Gasgacinch instructions.

Some gaskets come with a factory sealant coating.  They do not require additional sealer.  You can see the sealant coating on the gasket.  Sometimes a gasket or gasket set comes with assembly instructions.  Often, there will be sealing instructions and sealant recommendations in the factory shop manual for the motorcycle. 

For minor scratches in aluminum case mating surfaces, a cut paper gasket can compensate.  Either factory sealant or Gasgacinch will help here.  Gaskets like you describe have enough thickness to compress into tiny scratches.  If scratches on aluminum machine surfaces need flattening or leveling, that would require touch-up with fine crocus cloth.  Be sure not to distort, gouge or remove too much material!  Surfaces need to remain square.

Some finely machined engine and transmission cases mate directly together without the use of a gasket.  Factory assembly includes a sealant between the case sections (no cut paper gasket).  Sealers like Kawasaki's Kawabond Liquid Gasket, ThreeBond Case Sealant Liquid Gasket (Gray) and Hondabond 4 Liquid Gasket get applied along the mating surface.  However, if an engine calls for a cut paper gasket, the gasket must be used.  The machining and engine dimensions require the gasket's thickness to get the right spacing between the parts.

Of course, we try to avoid making scratches.  This can be difficult with aluminum.  I avoid using scrapers or metal brushes of any kind.  Some ways to remove remaining gasket material safely are gasket solvents (protect yourself from the solvents!) and 3M fine abrasive discs.  Start with the finer grit discs to be safe.  Lubricate the disc with a penetrant oil/solvent.  Slow the drill speed if possible.  See the 3M catalog below and look for materials that will not damage aluminum: 



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