Farmall A Valve Seals

Several months ago I posted a message about my newly overhauled A and how it smoked on startup and at idle. I had installed new valves and guides, so thought that couldn't be the problem. However, I did as someone suggested and ran the engine with the valve cover off. Oil just ran out of the rocker arms putting a lot of oil in the rocker arm/valve area. So I got some umbrella seals from the machine shop that did the work and installed them. What a difference! It doesn't smoke at all any more when running, when idling and on startup. Before the overhaul it did the same thing, so part of my smoke problem to begin with was the valves (there were other reasons it needed an overhaul). Thanks for the ideas to try. Roger

I'm guessing you're a "greenie"?

To a certain degree you are trading valve guide life for a reduction in smoke.

Is it REALLY important that an antique tractor doesn't smoke?

Some of us think a little smoke adds character!

Not likely any umbrella valve seal will cause you any valve guide wear problem. At best they just slow the flow some. A good valve seal like Perfect Circle with the teflon ring does a real good job and still allows for lubrication. I understand some of the newer seals are even better. When those rocker arms shafts and bushing in the rocker arms wear you can throw way too much oil on the valves like you observed on your tractor.

Like Pete said valve guide wear is not an issue and smoke means pollution which we don't need!

I've been putting valve-stem seals on farm tractor and industrial engines for 40 years. Never had one die a premature death over it. And, I'm no "greenie." Not really a big issue on most diesels that don't have engine-vacuum, but it can make a big difference on gas engines or air-throttled diesels.

John Deere was one of the first to install positive-seal type stationary teflon seals in 1960 on 1010 and 2010 gas engined farm tractors and crawlers. Worked fine and their valves lasted just as long as anything else out there. These stationary seals let even less oil down the valve stems then umbrella seals.

Do you have a part number of the seals you use on the A? How about other applications V.S. that will work?

Just go by the valve-stem diameter. Umbrella seals are universal fit and go by size-ranges. You can easily look them up down at NAPA in the parts book by size instead of application. They only cost around 20 - 90 cents each and stretch quite a bit. Main this is the OD has to fit inside the springs. Just a few sizes will fit almost every tractor made (within reason). These umbrella seals go up and down with the valves and act as "umbrellas" to keep oil from running down the valve guides.

I haven't bought any new, across the counter, in years. That because I used to do a lot of head, and engine rebuilding at a Deere dealerhip, and have buckets full of seals from over the years. Mostly leftovers from engine kits, or certain jobs.

If you want stationary positive-type seals, things are much different and they usually aren't worth the bother. They go by the exact size of the valve-stem and also - the tops of the valve-guides have to be machined for them to fit on. they clamp tight to the top of each valve guide and the valve moves back and forth through them. They are cheap, but won't fit most tractors without machining - unless the tractor came with them new. Now adays, it's all that is used in new engines of most makes.

SEP MV1796 umbrella seals at NAPA are 19 cents each and have a .315" stem-hole. So they'll fit many that are slightly larger diameter.

SEP MV1921B umbrella seals at NAPA are 99 cents each and have a bigger stem-hole at .337"

One of those is likely to work fine, but I don't know off hand what diameter your valves are.