Found a part number on the master cylinder so I'm good to go for that now!

It's a FD6656 made in the USA by Wagner Lockheed.

Thanks for the help so far!

A few pictures of the master cylinder.

The original cap was an aluminum one, with a square on top that broke when trying to get it out. The cap on there now is a homemade one from a hockey puck.
[img]https://i.imgur.com/qOUXUfV.jpg[/img]
[img]https://i.imgur.com/6hrvxTI.jpg[/img]
[img]https://i.imgur.com/VOXhUYo.jpg[/img]
[img]https://i.imgur.com/K0cmewI.jpg[/img]

Drillbit,

Looks like an old G51C, probably a 4 to 5000 lb lift. I think I can find a part number for you, but TVH or other aftermarket forklift parts will be the only place to find. Will update when I have some more info. Thanks.

Here's a few pictures. I can take more and post them if it helps.

[img]https://i.imgur.com/HLK5jOk.jpg[/img]
[img]https://i.imgur.com/Tb8Gzh7.jpg[/img]
[img]https://i.imgur.com/obZMJtW.jpg[/img]
[img]https://i.imgur.com/D6ctf2h.jpg[/img]

The other gentleman is correct, one letter six numbers for the serial number. I don't recall seeing a 6 cylinder in anything smaller than 7-8k capacity and the only Dodge engine in a Yale was a slant six. If it is a flathead it is probably a continental engine. The master cylinder on that vintage would be very common and you could probably match one up if you have a TVH book. A picture of the master could be very helpful for someone who has been in the industry for a while.

Drillbit,

From 1940 to 1957, the serial numbers included the year. The first two digits were the year. This is for gas and electric trucks. If they were warehouse lifts and worksavers, the year was the 2nd and 3rd number. Also, the serial numbers were only 6 digits. I would check for another number somewhere on the frame. If you have a floor plate, remove it and check just under that. Depending on how much paint is on the lift, may be hard to find. Check the frame just above the transmission. A picture would help.

Ok, thanks!

So it must be older than 1958 I guess?

I'm thinking I'll need a master cylinder for it, that's why I'm trying to figure out how old it is.

Drillbit,

Most of the Yale serial numbers are 6 numbers long and set in blocks. From 1958 to 1968 the serial number would have stated with letters. AB = 1960, AC = 1961and so forth. From 1969 to 1994 all serial numbers run in blocks. 1973 runs three different sets. 213739 - 219999, 220000 - 232908, 230000 - 242000. Each year is like this up to 1994. Then they went with a 11 digit alpha numeric serial number. Good Luck