Topic: Correct water pump bolts for 68 200 I6

[Shineycarb]

Hello all
My questions are in regards to a 68 plain Jane coupe with a C4 trans and 200 engine. 
I have been having a hell of a time getting the water pump to seal.  It has a slow leak ever since it came back from the machine shop/rebuilder and I have attempted to seal it more times than I'd like to admit. There is one through bolt that seems to be the issue, even though I use high temp RTV on the threads...but the coolant continues to drip out of this bolt.  It is the 2" bolt below the alternator bracket.  I have even bought a new set of bolts from AMK Products.

I've worked on numerous 289s and 302s; I've never had this amount of frustration trying to get the water pump to seal!

Question #1.  The Hardware list on your site lists the 3 ea water pump bolts as: BOLT,HEX,LOCKING, 2 have a NYL STRIP and 1 has a NYL PEL.  I get that something is nylon but what is STRIP and PEL?  This abbreviation is not listed in the notes.  Also, should these have a lock washer as well?

Question #2.  What am I missing?  I've removed the water pump, cleaned all mating surfaces, ran a tap into the through-bolt hole to clean threads, used a fresh gasket each time, have used Permatex RTV blue and black sealant specifically for water pumps.  As I said I've even bought new bolts which I torque to the shop manual specs...but they did not come with lock washers or any sort of nylon piece.  My rebuilder even gave me a new water pump to try.  I make sure the mating areas are dry and I let the RTV cure for days before I fill it up.....but it always leaks.

[Bossbill]

First, RTV and regular gaskets fight each other. Together they do not help sealing.

On the "NYL STRIP" it might indicate a nylon strip embedded into the bolt threads along its length. Usually closer to the end of the bolt.
Imagine a keyway cutter cutting into the last quarter thread length and nylon being inject into that recess. I've seen it on seat belt bolts. Like nyloc nuts, they hold the fastener in place.
"NYL PEL" could be nylon pellet, like the nuts on the steering coupler that have an embedded nylon pellet on the side of the nut. Not sure how that would work on a bolt.

[jwc66k]

On the "NYL STRIP" it might indicate a nylon strip embedded into the bolt threads along its length. Usually closer to the end of the bolt.
Imagine a keyway cutter cutting into the last quarter thread length and nylon being inject into that recess. I've seen it on seat belt bolts. Like nyloc nuts, they hold the fastener in place.
"NYL PEL" could be nylon pellet, like the nuts on the steering coupler that have an embedded nylon pellet on the side of the nut. Not sure how that would work on a bolt.

Yes to both of the "might" and "could". Both the strip and pellet are designed to have an interference fit and deform as the corresponding thread "passes" by. Back in the 1960, the USAF conduced a study on nuts and bolts. The use of "nylon retention" was forbidden in design.
Jim

[Bossbill]

When I do plumbing thread joints I use "white tube" thread sealant.
When I plumb LPG gas lines I use "Yellow tube" thread sealant.

RTV is not a thread sealant. It's actual uses (not the advertised uses) are quite limited and are usually as a gasket replacement between two highly machined surfaces (gray) and in valve cover, intake rail and pan areas as a bridging seal.
I wish I could buy a small 1 ounce tube of it since it mostly sits on the shelf and becomes a hardened mass.

Use a real thread sealant.

[jwc66k]

I wish I could buy a small 1 ounce tube of it since it mostly sits on the shelf and becomes a hardened mass.

I keep most of my chemicals in the bottom of my beer 'fridge, a 65 year old Philco. (There's white wine in there too.)
Jim