Agree with ABE, worked for a company that installed 2000s also prior to that worked for US. Back then they couldn't even get it right on a 1 stage jack. Imagine a 2 stage jack it's like double the trouble.

Little story here, was working for US when they came out with their own 2 piece jack. First time we found out there was a problem when the LR in Eastern Washington called a said the hoistway sill and not to mention the carpet at the 3rd floor was getting soaked with oil. We had another 2 piece jack ready to install out in the yard. The engineers in SD figured that bolting the two sections (similar to ESCO) with 4 bolts and no seal would do the job. The rest is up to your imagination.

Our fix was overfill the space with Silicone seal and bolt the things together so there was no room for oil in the joint. Somewhat Caveman but seems to work then.