What size jack?

[Jriddle]

Here is some pictures of my manual.

John

[Len Silva]

You also want a pad to put under the jack.  I have a couple of one foot squares of 3/4" plywood.  You definitely need it on dirt or gravel, and even on blacktop on a hot Florida day.

[Ed Hackenbruch]

 I use a couple of 1'x2' x1/2" steel plates for under my jacks.

[kyle4501]

I've blown out the seals on a 10 ton jack while jacking up the rear axle of a school bus to swap tires with my dump truck.

That is why I like the 20 ton jack - less stress on the seals for the same weight.

The air over hydraulic is a very nice work saver - IF you have compressed air available.  

[it_mike]

I've blown out the seals on a 10 ton jack while jacking up the rear axle of a school bus to swap tires with my dump truck.

That's what I was worried about.  I'll go with the 20T (on sale at Northern Tool...yeah!)

One of these days, someone will have to show me how to tie into the air system.

[bevans6]

It's a bus - it always has or needs compressed air!   

I carry a generator and a compressor anyway, in  case I feel the need for a stealthy getaway I can air up the bus without running the engine.  I put quick connects and ball valves in two places - one on the ping tank where I put air into the system through the air dryer (always stop the bus on a compressor charge cycle so the purge valve is closed) and one on the accessory tank drain for taking air out of the bus system. 

Brian

[kyle4501]

It's a bus - it always has or needs compressed air!   

I don't know so much about the always has part, but I can confirm the always needs . . . 

When I have compressed air, I don't notice wether or not I need it - it is when I don't have it is when I seem to really need it the most . . .     

One of my air over hyd jacks is either-or & can be used manually. The other one is air only - useless without air.  They use copious amounts of air too.