Oiling 40 Ford Convertible Top Vacuum Cylinders?

[glennpm]

Hi,

Does anyone have an easy technique for adding a little oil to the vacuum operated vacuum cylinders? I'd like to just disconnect the air hoses at the operating switch.

I usually just operate the cylinders twice a season so they get little use. A week ago I lowered the top and it was a little slower than normal. I use the switch to get the top around straight up, move the vacuum switch to the middle, and then finish the lowering by hand.

Glenn

[Kube]

Glenn, I do not believe you will be able to effectively oil the cylinders via the operating switch hoses.
Rather, you really need to raise the top and access the hose that goes to the top of each cylinder.

Introduce some very light weight oil via the upper hose nipple. I'd suggest sewing machine oil. Or perhaps 3 in 1 oil.

[glennpm]

Thanks Kube, I was hoping you'd reply. Looks like it's a job for a rainy day. Yes, I would use a light oil. I have both you mentioned and used a third, air tool oil, when I serviced my wiper motor last year.

Glenn

[blucar]

You might be going about the process of adding lubrication to the vacuum top assembly by doing so at the operation valve.
I would suggest the removal of one of the hoses on the top of the cylinder, apply a small amount of 'Neatsfoote' into the cylinder. The seal on the cylinder plunger is leather so you have to be careful with the type of oil and amount you used.
I could not find anyone to work on the vacuum cylinders for my 39 Plym convertible coupe, the first car convertible to have a power top. I rebuilt the cylinders myself using a 3.5 inch engine cylinder hone, the ball type, soaked the leathers in neats-foote oil.. The car had been sitting for 38 years in an open field in Montana when I got the car. Surprisingly the leathers were still pliable. the chrome on the shafts were badly rusted so I had new shafts made out of stainless steel, slightly over size to allow for ware in the upper bronze bushings in the cylinder cap.

[petehoovie]

Originally Posted by blucar

You might be going about the process of adding lubrication to the vacuum top assembly by doing so at the operation valve.
I would suggest the removal of one of the hoses on the top of the cylinder, apply a small amount of 'Neatsfoote' into the cylinder. The seal on the cylinder plunger is leather so you have to be careful with the type of oil and amount you used.
I could not find anyone to work on the vacuum cylinders for my 39 Plym convertible coupe, the first car convertible to have a power top. I rebuilt the cylinders myself using a 3.5 inch engine cylinder hone, the ball type, soaked the leathers in neats-foote oil.. The car had been sitting for 38 years in an open field in Montana when I got the car. Surprisingly the leathers were still pliable. the chrome on the shafts were badly rusted so I had new shafts made out of stainless steel, slightly over size to allow for ware in the upper bronze bushings in the cylinder cap.

Your '39 Plymouth is a good-looking car. Nice lines...

[Kube]

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I would not introduce oil at the switch as it would be sucked back into the vacuum source, not directed to the canisters.
If the top is in the closed position, the piston of each cylinder is down. Introducing oil via the top nipple will allow the oil to get atop the seal.

These tops never worked like the show car at the '39 world's fair. For full disclosure, Ford had a compressor rigged to that car making the top lower and open so smoothly and wonderfully.
I'd restored a number of convertibles. I do hone the cylinders and if the rods are pitted, replace them with new of the same diameter. There is a rubber seal at the top of the tank that surrounds the shaft.
Often times, the small cork seal is absent between the cylinder and top plate, allowing vacuum to leak. When I assemble the canisters, I place a thin layer of RTV in that area.
On "driver" cars, I have installed an auxiliary vacuum tank beneath the rear seat. I install a check valve, typically used in a brake vacuum booster in line so the extra tank stays full of vacuum. Those valves are cheap and available at Napa.
This has proven to make the top operate much better.
Other things to look for are binding and / or worn pivot points.

[glennpm]

Great info, thanks!

Glenn

[blucar]

Kube is pretty well spot on with his description of vacuum convertible top assemblies.
I had a terrible time finding info on the assembly in my '39 Plym until I found out that the '40 Ford convertible top assembly was basically the same as the DPCD cars of '39-40, which are Briggs bodied. The major difference was the top seal on the vacuum cylinder. Chrysler went to a higher level using a bronze bushing in lieu of cork.

When I found my '39 Plym in '94 there were only thrity-one known cars accounting to the Plymouth Owners club, now there are eighty-one