Water neck install tips needed

[JohnJohn]

I truly hate Ford water necks. I have had so many problems installing them and not having it leak.
Either the thermostat falls out on the way in or slides out of the pocket or the gasket leaks.

I use Fel Pro gaskets with a light coating of black RTV that i let tack up and I lightly glue the thermostat in with a bit of RTV but nothing seams to be fool proof.

Please tell me your tips.

 

[DJs74]

I've experimented over the years - with gasket plus RTV, with gasket and no RTV, no gasket with RTV.
All have been successful and I've also had a few leaks. I very thin layer of RTV on the thermostat lip will help to keep it in place during the install.

I can't say one approach was any better than the other but I do always use RTV because it compensates for surface imperfections and ensures a reliable seal.

Probably the best solution, and I haven't used this on any older SBFs or BBFs but many times on later model engines is a water neck with an o-ring seal... no RTV or gasket.


DJs74

 

[NicksTrix]

be sure the neck is flat on the sealing surface

 

[toddz69]

I think everyone hates them!

I use a thin coating of Right Stuff on either side of the gasket. Seems to work well.

Here's a trick I use now to hold the thermostat in place. Wrap some dental floss around the thermostat piece that sticks into the housing and route it up through the top of the neck. Tie it around a pencil or some other small piece of wood or rod and then twist the pencil or whatever until the floss is tight enough to hold the thermostat in position. That will keep the thermostat from slipping when you're maneuvering the housing into place. After things are bolted into place, cut the floss and pull it out through the top of the neck.

I also let the RTV/silicone/Right Stuff etc set up overnight before I fill the cooling system too.

I had one a few years ago that I couldn't seal to save my life - I finally decided the intake end was not a flat sealing surface anymore.

Todd Z.

 

[ENDLIFE]

The best method I use, I was taught by an old engine builder, and It has been flawless. His secret to almost any build was to spray down one side of the gasket with a simple spray adhesive and then stick it to the part that is to mount to the engine. However, he would never spray the gasket and stick it to the engine, as that was a huge no-no. I have used this method for years, and I LOVE it. I have even used it on metal gaskets for oil filter adapters, and I have yet to have a leak come back to the shop.

Correction: He would use it on intake manifold gaskets, and oil pan gaskets.

 

[cs_88]

Here's a trick I use now to hold the thermostat in place. Wrap some dental floss around the thermostat piece that sticks into the housing and route it up through the top of the neck. Tie it around a pencil or some other small piece of wood or rod and then twist the pencil or whatever until the floss is tight enough to hold the thermostat in position. That will keep the thermostat from slipping when you're maneuvering the housing into place. After things are bolted into place, cut the floss and pull it out through the top of the neck.

I've done this same thing with a zip tie and a small screwdriver.

 

[75302auto]

I agree with Toddz69. I use RTV solely. Install on a day you don't need to crank or drive it and allow the RTV to set for 24 hrs with zero liquids touching it. Snug it at first, then come back and tighten about an hour later. Fill fluids the next day and you should have a leak free installation.

 

[pcf_mark]

I put a few dabs of weatherstrip adhesive on the t-stat to glue it in place. Then I use a thin film of rtv on the housing, slip the bolts through the hole, put the good blue Fel-Pro gasket on, put a thin film on the block side of the gasket then fit the whole thing in place.

As Nick noted if the housing or intake surface is not flat it will leak. Just assume any aluminum housing is not flat. You can get a new cast iron one at NAPA or AutoZone that is also drilled and tapped for a fitting on top which comes in handy.

 

[JohnJohn]

Thanks guys. I ordered 3 more gaskets this morning and will pull the neck off this weekend and give it another go.
I like the dental floss idea and I will use a straight edge I have to double check this aftermarket neck i am using.

I don't have much room on this EFI motor so i knocked the thermostat out on the way in. I also started to fill about an hour after I installed the gasket. I will give it a day before I top it off.

 

[SevenT]

Water neck

John,

I use a zip tie and a nail to hold the thermostst in. Run the zip tie thru the steeple on the thermostat and put the nail over the hose opening (make sure the locking end of the zip tie is next to the nail for removal). Use your choice of gasket sealer to put the gasket on and let it seal (5 to 10 minutes). Gasket sealer on the intake, then bolt the water neck on, then grab the zip tie with needle nose pliers, then cut the zip tie. I have done this for 16 years with no leaks. Good luck.

v/r,

SevenT

 

[JohnJohn]

Ahhhh... now I understand how to use the zip tie. I was wondering how you got it out at the end.
Great Tips Guys!!!

Is funny... I completed a frame off by myself, rebuilt my C4 by myself, EFI conversions, did many ring and pinion changes but the freaking simple water neck kicked my ass.

 

[SteveL]

Like they said make sure it's flat. I've found most of the pretty aftermarket ones arent. Any more I only use the cast iron ones from the local ap store. While it's apart drill a 1/8" hole in the t-stat.it helps keep out air pockets.

 

[Rustytruck]

Make sure the step for the thermostat is deep enough. Install the thermostat in the housing. I then glue the gasket in place over the thermostat housing using gasgacinch adhesive. Now before I mount the housing to the intake I clean the surface and then smear the thinnest film of rtv on both the intake and the housing gasket and let them fully tack off. Only then bolt it all up.

 

[ransil]

I always use weather strip adeasive ( aka monkey snot ) put it on both the gasket and the housing in a few spots let set for 15 minutes before putting the 2 together.

 

[englewoodcowboy]

I use gasgacinch on the gasket however I do place 3 dabs of rtv in the flange and set the tstat in it and let it dry. I drill a hole in the top of the T stat to let air escape easily if your tstat does not already have one with a little brass t check, those must be oriented up. I also have bought some housing gaskets that have a peel and stick adhesive in them from the factory and they have worked well.

 

[ntsqd]

Also, Chrome housings are notorious for not sealing and not being flat. Stay away. One engine I couldn't buy the needed water neck and had to make it out of stainless (figured I only wanted to make one once!). Flange is 3/8" thick plate, made from sched 40 SS pipe, a weld elbow and a pipe cap:

 

[gambling209]

I use a rubber band to hold the thermostat in place