Favorite sealants for tractors

I'm going to help cousin finish NAA rebuild soon.

Just wondering these days what is preferred sealer/coatings for various.....

Head gasket

intake/exhaust

water pump

pushrod cover

I've done plenty of motors, old standards sure will work, is anything new "better".

I have never overhauled an N engine so take
this with a grain of salt.
I have been through a number of 3 cylinder
tractor engines and other engines too. And
I've replaced a lot of external componants
on them.
I do not use any sealant.
In a couple of places where gaskets meet
like where the pan bolts to the block And
seperate timing cover I will use a tiny bit
of silicone. But generally I assemble every
thing with a clean, dry gasket.

Based on your list only one you may need sealant on is pushrod cover.

Yep, I concur with Ultradog, none required. They didn't have any goop originally. The head has a gasket, metal if you prefer but no goop. Manifold, carb, engine
inspection covers, and a few others all use paper gaskets. Bolts and nuts only used a dab of clean engine oil for lube. I have done a half dozen N's like this with no
issues whatsoever. That being said, I'm sure others will plug in their perspective, and of course it's your tractor so do whatever the hell you want to it. And still
people post until they hear what they want to hear as well no matter what common sense and logic says. I just find goop a waste of time and money. What do you mean is
there something better??? If you have leakage issue, it isn't a gasket problem inle it is missing, you have another issue going on. I once worked on a guy's tractor that
he had put 6 paper gaskets on his manifold. 6 on each side!!! Instead of fixing the root cause problem which was a worn surface at #4 port.

Tim Daley(MI)

I could give you a profession opinion on the subject but its not needed.

Sealants are used to seal imperfections, Joints, and minor alignment issues and I doubt a 70 year old tractor engine is Palestine. Different engines use a different approach so live and learn. Its your time your money it depends on if you are willing to do it over are join the they all leak club.

Its amazing modern OEM manufactures actually recommend sealants when needed to resolve minor imperfection issues that arise. So there is no one correct winner : (

Every time I think modernization has resolved the issue it has its on issue. There is noting modern about your engine so some imperfections need attention. Unless it has a perfect finish a prefect fit you will need to attend to that.

OK so no general concensus.

In the past on SBCs I rebuilt ,I used Permatex Aviation Form a gasket on most all stuff that would not have to come apart often. It worked great and never had leaks. I also used it on bolts that threaded into water jackets. The big bottle with the brush on the cap might still be good?

When I worked at a motorcycle shop, for cases and covers, we used a very thin film of RTV silicone applied to the gaskets before they were installed. Have done this with water pumps and sometimes carb gaskets too. Bike head gaskets usually went on dry.

Valve cover gaskets I've used a bead of silicone on the cover side only. If you took the cover off the the gasket would come with the cover and could be easily replaced if needed.

Anybody see a problem with what I've used/done in the past?

I've considered trying the Permatex Copper spray for both the head and manifold vs the Aviation Form a Gasket. Experiences with this stuff? The head was surfaced at the machine shop when the valves were done and it's a new replacement manifold. Block surface is very clean, used wet/dry paper on a small piece of plate glass with diesel.

One more question on the NAA. Are the head and water pump bolts blind, or some go into the water jackets? IE do the threads need sealer? I'll use the Aviation Form a Gasket here if needed.

Thanks for your suggestions and thoughts. I'll go back to the thread I started a while back at the start of the project, and update the work there.

As a reminder, this started as a "tune up". Found distributor needed work and didn't run right after ignition work. Head gasket was bad between #2 and #3. Surprised it ran at all on two cylinders. A couple valves leaked a little, so got the head went through at machine shop.

To give you something to research while I chiffer the rest this is gonna be on the top of the list. Rear Main oil seal : ( BTW this is a common Ford rear seal and used in your engine.



https://forums.yesterdaystractors.com/viewtopic.php?t=1474683&highlight=seal

(quoted from post at 19:06:55 03/26/23)
The big bottle with the brush on the cap might still be good?

Click to expand...

Just to add my two cents. I used all paper gaskets and the purple sticky stuff brushed on one surface just to hold the gasket in place during assembly. I did try the Copper Coat for the head gasket and Manifold simply because I had never tried it before and I am sure I read some where that it can't hurt. I also tried RTV on the Governor to make up for a slightly warped mating surface. I "think" the oil weeping out is less than the paper only gasket but I long stopped worrying about weeping oil..... I now tackle leaks when they are dripping. :wink:

I am not a professional Mechanic,but have been working on stuff for about 55 years now. I started using
Gasgacinch many years ago to stick the gasket to the part,a thin coat,then a thin smearing of grease to help
with removal if necessary. I have found that silicone tends to be put on a bit thick and sloughs off into
the engine. Radiators can be a problem when clogged with excess silicone,as can oil pump pickup
screens,causing mayhem. At one time,I bought wrecking yard motors to rebuild as hotrod motors,more
recently,I got dirt-bike motors to rebuild as racing motors. Some of the wrecking yard motors were full of
strands and clumps of silicone. This is not advice,just a suggestion based on a long history of various
motors.