On Monday, December 1, 2008 at 3:36:00 PM UTC-8, wrote:
I am looking for a source for a replacement bottle jack for a cobra
trailer ramp (yes, I know I should switch to the mechanical jack and
all problems will go away, but I don't want to go down that route
yet). The Torin 2-ton jack that Walmart and Autozone sell is extremely
poorly built, in addition to the dimensions not being quite right.
Somebody must have gone through this before and found a decent source?

Yes, another old thread brought back from the not-so dead.

Wings And Wheels are currently out of stock of hydraulic jacks (August 2017).

Tractor Supply and Pep Boys both have the pseudo- replacement for the standard single-seat Cobra jack. The same Torin Big Red 2-ton Hydraulic Floor Jack, SKU 0116479 or 1024519. They have been on sale for $20, but not visible on the Tractor Supply website right now.
CAUTION: Because it's typical Chinese rubbish, there will be slight differences in construction due to which children would work the cheapest when the order came in.
I found the Tractor Supply part 0116479 had the pivot point for the actuator arm slightly higher than the one that was in the trailer, so needed to drill and add a steel rivet and washer to provide the upper stop for the foot pedal. Also drilled a shallow hole in the end cap of the cylinder for the end of the return spring to sit in.
The bleed valve to lower the Tractor Supply jack had different threads to the part removed from the trailer, so no easy swap there.
Jim