SM Live Pump Suction Hose

kopeck · Mar 13, 2014

Good morning,

I'm have a '52 SM that has been converted to live hydraulics using the belly pump as a reservoir with a IH pump.

I'm collecting all the parts I need to install my Saginaw 3-point hitch and part of that is I'm going to replace the hydraulic hoses (what's on there are all pretty worn).

The one thing that always stuck out to me on this machine is the PO used a pretty huge suction line, pretty sure it's 1 1/4". I guess it being bigger doesn't hurt but what size line can I get away with? Looking on line most pictures show something more like 3/4", which is what the outlet/pressurized hose is at the moment. Right now it looks like I have a sewer line on there!

The pump isn't a huge GPM/PSI pump by any means.

K

DeltaRed · Mar 13, 2014

I used 3/4" hydralic hose on mine.Look at the
fitting size.That will pretty much tell you the
size of hose.

kopeck · Mar 13, 2014

(quoted from post at 07:33:14 03/13/14) I used 3/4" hydralic hose on mine.Look at the
fitting size.That will pretty much tell you the
size of hose.

I'm going to have to go out and look but I'm guessing the PO had to up size the fitting to get that hose on there.

K

Janicholson · Mar 13, 2014

The intake side should be almost twice the flow area of the output. (Not twice the diameter!!) The area of 1/2" pipe is about .19 sq inches the area of 3/4" pipe is .44sq inches.
The reason for this is because the suction side depends on air pressure to push hydraulic oil into the pump, if restricted at all, the pump cavitates and that can ruin it, as well as restricting flow.
The pressure side has pressure forcing it through the hose.
It is the same reason intake valves are bigger than exhaust valves. Jim

D Slater · Mar 13, 2014

SM that came with live hydraulics used what's called a 1 inch suction hose and a 3/4 pressure.
Will be bigger on the OD. Manifold block that bolted to the pump had 1 and 3/4 inch pipe threads. M&W pumps on the tractors used a 3/4 suction and pressure hose. 3/4 would probably work for you. Only thing to watch for is the ends installed on some newer hose has openings a lot smaller than old hose or the hose IH used. Also depends what size hole the reservoir suction opening is tapped to.

notjustair · Mar 13, 2014

Mine is an inch on the suction side and 3/4 on the pressure
side. Uses the belly pump as a reservoir with an additional
tank mounted on the frame rail.

mkirsch · Mar 13, 2014

1" diameter is about .78 square inches
3/4" diameter is about .44 square inches

Still pretty close to that magic 2:1 ratio.

kopeck · Mar 13, 2014

Thanks for the info.

I went out and gave it all a good look. The suction looks like a 1" port upped to 1 1/4". Not sure why they would do that, maybe they just had the stuff laying around.

The outlet is 3/4".

Pretty sure the IH Christmas tree valve is 1/2" all around but that's easy to take care of.

I'll stick to 1" on the suction.

Thanks guys,

K

SM Live Pump Suction Hose

kopeck

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DeltaRed

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kopeck

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Janicholson

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D Slater

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notjustair

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mkirsch

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kopeck

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