Since you said "cylinder", I am assuming it only has one steering cylinder. The CK (Construction King) model has two.
If it only has one, then it should be a 430 utility/ag model. Now comes the fun part... You need to check and see if it is the heavy duty axle. Easiest to go to Case/IH parts search,
Case IH Agriculture & Farm Equipment and look real close... There is a difference in the front spindles, in the way they are shaped. You will also need to find your tractors serial number.
Or..., if you can find the part # on the cylinder. Probably on the part where the lines go in. Case/IH shows the cylinder # as G14451. for on the HD axle.
Then they show a 430 with loader, prior to SN 82628000. This cylinder # is G45312.
If by chance it is the G14451, these were also used on the 530's, w/HD front axle...
The good news.... Unless it is T-totally trashed, and just leaking... Seals & O-rings are still available to rebuild them.
Actually, the G14451 is still available, new through Case/IH. The bad news... $2100.00+
Depending on how quick you need it, I saw several over the past year on ebay. Most could be bought for $150.00, or less. But you're getting a pig in a poke...
Or, you can follow this link to Tractorhouse
Used Tractors For Sale at TractorHouse.com: John Deere Tractors, used farm tractors and farm equipment, tractors for sale, Case IH, New Holland, Agco, Kubota In the top ledt menu, there is a place there to place a free "want to buy" ad. It goes to numerous salvage dealers all over the U.S. I've found several hard to find parts using this feature. I do believe you need to register with them to do this. No charge, it is free. Most will contact you within 48 hours, if thye have the part.
I tried searching for a 430, and 530 in salvage yards, but none to be found...
Hope this wasn't too long, and confusing...