MTFCA Forum

I have an oil leak. Its been there for years, but never noticed a large loss of a lot of oil.

How common are oil leaks with a Model T?
How do you locate the leak?
Where is a leak most likely to occur from a Model T?

Very common. Mostly from the ball cap, also no matter what I do there's always a drop or two from the oil drain plug. Its not hard to track down the leaks...just crawl under the car where its been dripping and look "straight up" from the evidence!
On elec. cars the starter can be a major source of oil leaks, unless you install one of those neat oil seal kits on the shaft. They work! A failing front oil seal is also a good source for leaks. And of course the infamous hogshead will always seep oil either from the shafts or the bolts. Stopping them is a work in progress but moat can be stopped, or at least slowed down a bit. Have fun. They love to mark their territory!

If your Model T isn't leaking oil, it's because it's out of oil.

An engine with loose bearings and/or poor ring seal will emit more oil than an engine with tight clearances. A postive crankcase ventilation system would reduce oil leakage and offer other benefits. A number of available PCV valves would probably work well on a T engine, and could be connected to the hole in the block or the valve cover where the throttle linkage passes through. The other hole would be need to be blocked. That would require using the late-style throttle linkage and adding a breather-type oil filler cap to allow air inflow and to prevent pressurizing the crankcase under load at low manifold vacuum. I'm not sure what, if any, carburetor modifications would be needed in order to accomodate such a set-up. Early 1960s Ford engines, like the 223 six, had PCV systems grafted on to existing designs with no evident carburetor modification. They simply connected the PCV valve to the road draft tube port in the block and connected the PCV valve to the intake manifold plenum area. I suspect that the air flow rate of the oil filler cap may have needed to be restricted somewhat. Besides reducing the tendency to leak oil, such a set up would improve upper cylinder lubrication, improve crankcase ventilation, and reduce emissions somewhat. A tight engine would see the most benefit, and a well-worn engine would see the least.

My current nemesis is the clutch shaft. I even have a spring loaded cup with an O ring inside. Not willing to cut an O ring grove in the small shaft. I think the oil screen is exacerbating the problem by dumping excess oil on top of it. The second hot spot is the front crank seal. Crank was not polished where seals run. Inside & external seals leak. May need a repair sleeve.

Successes: Black ultra RTV does real well on all the gaskets. Pedal shaft cams O ringed.
Current success with sealing the drive shaft flange. Ball is lightly oiled. Flange rear opening is chemically cleaned & beaded with ultra
black. Let to dry over night. Not a drop yet, but only a hundred miles use so far.

I don't think PCV would stop oil leaks. They also are connected to the vacuum of the intake manifold which would affect performance and fuel mixture. PCV is to recycle blow by from entering the air, not for eliminating oil leaks. Most common leaks would be any gasket surface which is not completely sealed including the felt around the front of the hogs head. A new washer on the drain plug would also help that area, however the oil drip there might be from oil running down from other areas. Also any crack or unsealed rivet in the crankcase could leak. Worn seal at front of crankshaft and excessive wear around the pedal shafts. The ball joint under the universal joint should not have a gasket. Only gasket should be between the fourth main and the hogshead/crankcase. One way to keep the oil leak down is to have plenty of thick grease in the U joint and front driveshaft bushing.
Best to park the T with an oil drip pan under it.
Norm

A properly set up PCV system will hold a light vacuum on the crankcase during most phases of engine operation. That will reduce the tendency to leak oil and also help remove gasoline and water.

When I first got my T I remarked to my brother. I looked on the floor, it's not leaking oil. His response: "Wait till you drive it!"

Pat,
Do you have a PCV on your T? If so, how does it run?
Norm

I do not have one. If I had a tapped manifold, I'd try putting one on. I've replaced several carburetors on older engines, like 1960s Ford FEs and 318 Dodges with very basic PCV systems with non-application specific aftermarket carburetors and had no issues. The out of the box jetting and springs worked quite well. The T carbs are readily adjustable, and the PCV system flows very little volume at idle and low speed, light load operation due to the regulating action of the valve. At higher speeds and loads, flow volume is limited by diminished manifold vacuum. Anything that reduces crankcase pressure will tend to reduce oil leakage. A simple road draft tube about 1" in diameter could probably be plumbed to the rearmost valve cover and a breather-type oil fill cap could perhaps be added more easily than a PCV system. It would not be as effective, but would offer some benefits in improved crankcase ventilation. My car has a one piece valve cover with no throttle rod hole in it. The block does have a hole for the throttle rod. A small amount of oil mist comes out of it under some conditions, and dust and bugs could enter. I stuffed one of those expanded bronze type pot scrubbers in the space between the cylinders to act as a filter and bug excluder device. It picks up just enough oil to catch dust, and mud daubers, beetles and crickets cannot get past it.

If you're really determined, clean everything up, then:

https://www.youtube.com/watch?v=LYzTyTlnsr8

Probably the best way to find the leak is just look at the T. If you see
a T, you have found the leak, or MANY leaks !

Best way to get rid of the leak is to sell the T and get a Tesla.

Beware! The Tesla will lull you to sleep..... then crash into a bridge abutment!

Pans under new T's...you bet they leak!

Clean everything, then add UV dye to oil and check with UV light. Then again maybe not Would not want anyone to be too distressed.

Steve Jelf wrote: ↑

Thu Aug 19, 2021 10:18 am

Yesterday I saw a rendition of the Ford Universal Car sign. The motto under it was something like "Successfully putting oil back in the ground for over 100 years"

Looking back at indoor dealer photos, would be safe to state that Ford supplied drip pans with every car delivered?

I'd guess fancy dealers used pans, or hired a kid as a wiper. More typical dealers probably used sawdust, cardboard, or just let 'er drip. Frugal dealers probably used pans or old oil cans to collect the oil for use in shop oil cans. About a hundred things on a T need a few drops of oil from time to time. A little motor oil cut with a little kerosene and mixed with dry sawdust made a good floor sweep compound.

Adam Doleshal rebuilt my engine. I drove the car from Milwaukee to Detroit and back. Car still does not leak. Saves me on buying oil.

You have a very rare car there.