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Bus Discussion => Bus Topics ( click here for quick start! ) => Topic started by: Cary and Don on June 16, 2011, 08:50:03 AM

Title: Air Jack
Post by: Cary and Don on June 16, 2011, 08:50:03 AM
We want to weigh the axles on our Eagle.  We have 20 ton air jacks and was wondering if there is a way to attach a gauge to the jack to do this.

Don and Cary
1973 05 Eagle
GMC 4107
Neoplan AN340

Title: Re: Air Jack
Post by: Len Silva on June 16, 2011, 09:06:49 AM
If the jack has a gauge port, it's pretty easy.  I would use a 10,000 lb. gauge and good quality hydraulic fittings.

Use the diameter of the jack piston to get the area and use that as a multiplier.  For instance a 1" piston and 10,000 Lb load would read 7853 on the gauge.
Title: Re: Air Jack
Post by: TomC on June 16, 2011, 09:08:07 AM
I don't know of a way you could get an accurate reading from the air jacks since the air pressure is used to pump on the hydraulics of the jack.  Individual platform scales are made that you can put under each set of tires to read out-course these are expensive and don't know anyone that rents them out.  Easiest is just plainly drive the bus to a truck stop and use the Cat scales splitting the axle groups on the split platform scale.  The weight should cost maybe $10.00.  Good Luck, TomC
Title: Re: Air Jack
Post by: HighTechRedneck on June 16, 2011, 09:29:35 AM
I second the suggestion of using the truck stop scales.  I did that on a trip and it even gave me the weight of my toad separated out as an additional "axle".  Couldn't have been simpler and was only $8 (that was a couple years ago).
Title: Re: Air Jack
Post by: Len Silva on June 16, 2011, 09:52:44 AM
Truck scales are fine but if you are trying to set up the bogeys on an Eagle, you need to be able to weigh them in the shop.

A cheap 12 ton bottle jack with a pressure gauge works fine for that purpose.
Title: Re: Air Jack
Post by: ojgetaway32 on June 16, 2011, 10:44:28 AM
Tractor-trailer drivers who obsess about knowing their weight in real time often use load gauges on their air bags.  It's a matter of aftermarket air pressure sending units on the bags and dash gauges.  The only problem is your steer axle is probably spring not air, so you can't get a gross weight just axle weights on the ones that are air ride.
Title: Re: Air Jack
Post by: luvrbus on June 16, 2011, 12:22:34 PM
If it is a HF jack you have to drill the boss on the bottom not the cylinder part but on the side where the flat boss is and tap it there check some better jacks have a plug for the gauge if you have 1 of those
In the Eagles manual they use a 12 ton with a gauge,I bought mine from these folks www.hyjacks.com (http://www.hyjacks.com) but you still have to build the figuture for the jack and the wheel and you remove the outside dual to use it

good luck