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Hello,  I have the Gar -Wood hoist ready to install on the MACK AC & have 2 questions;

1  -  What type & viscosity of oil should be in this unit?  The lines are 3/4" pipe & it has a gear pump

2  -  What size of cable is usually on such a hoist?  

Thank you,

Jack

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I would measure the width of the groove in the sheave to get in the ballpark for the cable diameter.  If the manufacturer built it with a 5/8 inch groove pulley, they won't be running 1/4" cable.

It would be nice if there was some info on the cylinder tag for the oil needs!   That vintage cylinder may be using a leather seal so could it use something like a 90 weight gear lube?  I don't know.  A resource to check out may be the HCEA site.

http://www.hcea.net/

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The F series and the previous 1915 and up hoists according to the 1922  flyer from Detroit Wood Hoists call for  glycerin-based medium weight ( 60 wt to 90 wt ?) hydraulic fluid.  Than it was called for because it was corrosion resistant, non hydroscopic and fire resistant. Still made today. Atlas , ARCO and others make it

 

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Edited by 41chevy
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Thank you both for the replies.     By enlarging & scaling the pictures it looks like the cables are 1/2" diameter which fits well with the sheave as Jim suggested.       Is the flyer mentioned on line somewhere?    

I found the attached  chart that answers the mysterious relation between gear oil, engine oil & hydraulic oil. Medium weight would be in the range of ISO 68,  SAE  20 Crankcase & SAE Gear 80.       I can now speak with my oil supplier to see what is available.

Thank you again for the help.

Jack

 

Viscosity-Chart.jpg 

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I'll see if I can get a photo of it. It's so fragile it is in a plastic sleeve. I'll try to get one with out the flash or at least limit it.  Paul

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a couple questions as I am rigging up the same pump on my truck now. What is the thread type on the pump called that you adapted to npt? did you have the pump rebuilt and if so where did you find parts? and finally what oil did you settle on

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I had two sets of fittings, one has a 45 degree taper & a thread that is slightly larger & coarser than JIC fittings. These use 1" hydraulic tubing with flared ends.   The other set that I used has a rope packing under the nut, again using 1" od hydraulic tubing.  These have a small flare on the ends to keep the tube in place while tightening the pack nut.    To use these I turned the od of 3/4" black iron pipe to 1"  & turned the id to about 7/8" for about 3/16" to facilitate making the flare - carefully with a hammer.    The turning needs to be done before bending the pipe.

I have used ISO 68 hydraulic oil which is noticeably thick in our current weather.

My pump was not in bad shape & I overhauled it myself.   I think any parts would need to be made.   The main wear was on the replacement side plate where the gears ride.  I had it ground on the surface grinder used for cylinder heads & flywheels.      The gasket thickness is important - measure your old gasket.  Mine was .006 thick.

Something to check on your pump are the bosses that contain the gear shafts.   I have 2 spare pumps in poor condition, one has a cracked boss that has been brazed at some time & the one on the pump pictured leaked when filled with oil due to the same cracked area.  I think water has accumulated between the end of the shaft & the casting causing a frost break.    I was able to salvage an un-cracked side plate & hopefully it will be ok.   You would be wise to have your pump Maganfluxed .

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will thicker oil iso 68 to iso 100 be more likely to pump and not leak if the pump is a little worn? being that it is for a show truck, I am not looking for any exceptional performance, just for the body to raise without a load on it...

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Wood specified medium weight hydraulic oil & ISO 68 is a little heavier than a modern "medium" weight.   At about 40 degrees F.  it puurs about like heavy pancake syrup.   ISO 100 is not common around here & would obviously be thicker.

The drive shaft & control shaft both have rope seals that should not leak if tightened properly - much more forgiving than lip seals.

If all connections are sealed there should be no leaks. Loctite makes a very good thread sealer.  

    

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