Cat 257B High Flow question

   / Cat 257B High Flow question #1  

heliotrope

New member
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Dec 27, 2009
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3
Hi,

We've just purchased a snowblower for our Cat 257B. The problem is that it seems underpowered - not shooting the snow very far and bogging down under load.

When we switch on and off the High Flow switch while running the snowblower dry, there is no tangible difference in the rotation speed.

Can anyone confirm that there is be a noticeable difference when you switch on or off the high flow?

We are suspecting that the high-flow system is not working.

Thanks,
Joe from Minnesota
 
   / Cat 257B High Flow question #2  
Just from looking at the specs, you should see and hear a difference when you shift to high flow. Low low is 15.6 GPM, and high flow is 26 GPM.

Do you have a hyd schematic for the machine?

Is the snow blower sized for that model?

This is an example.

15 GPM to a 5 cu in motor, rpm will be 693

26 GPM to a 5 cu in motor, rpm will be 1201
 
   / Cat 257B High Flow question
  • Thread Starter
#3  
Thanks, J.J.

I'll double check that the snowblower is sized appropriately, and will take a look to see if there is a schematic in the manual or parts book.

Joe
 
   / Cat 257B High Flow question #4  
i dont know much about your particular snow blower or machine, but what is the specs for flow on the snowblower? if its sized to run on say 15 gpm, it may not be able to physicly flow much more than that thru the hoses and couplers etc thus not much change when you try and force more flow to it. are the hoses and couplers sized properly? i once saw a guy trying to run a hyd mower off an excavator that called for 45 gpm, with #8 ( 1/2 inch id) hose, couldnt figure out why it wouldnt wind up as fast as it should, wanted to replace the pump on the excavator till i convinced him to get bigger hoses and couplers first and problem solved!
 
   / Cat 257B High Flow question
  • Thread Starter
#5  
Thanks to you both for your replies.

The snowblower is rated for 24 to 42 gpm, so the loader's 26.2 high flow rate should be appropriate.

I've double-checked the connections according to the manual and they are correct....there is no other way for it to be hooked up, and the manufacturer is familiar with Cat hookups.

Looking at the parts schematic, there is a manifold in the hydraulic system that has solenoids related to high flow. We might take a look and wiggle the wires. Then it's time to call the Cat guys.

Thanks again.
 
   / Cat 257B High Flow question #6  
Put a volt meter on the solenoid that controls the high flow, and see if voltage is applied when you flip the switch to high flow. If the voltage is there, tap the solenoid, it could be jammed. Some solenoids have a manual on /off . Take it off and clean it, and don't over tighten when replacing.
 
   / Cat 257B High Flow question #7  
Put a volt meter on the solenoid that controls the high flow,

Some solenoids have a manual on /off . Take it off and clean it, and don't over tighten when replacing.
push_on_these.JPG


If the valve have these small push "pins" at the end of the solenoid, it can be used to manually force the valve to move. When valve is in neutral, that "pin" can easy be pushed in the lenght of the valve stroke, about 1/8"? (on both sides of the double solenoid valve). When valve is shifted the "pin" meets firm resistance immidiately, like a strong spring force.

I recommend using a soft material (woodstick etc) to push that "pin", to prevent from scratching the inside og soleniod housing. Scratches can easy interfere solenoid and valve from shifting.
 
   / Cat 257B High Flow question #8  
Now that its nearing middle of summer, i stumbled upon this thread..LOL...

You should be able to tell a considerable differance when switching to HIGH flow =overhead left toggle.....Do you have the jumper plug (not the plug cap protector) installed at your hyd port manifold on your loader arm ??? the high flow option will be inop if you do not have it plugged in....
 
   / Cat 257B High Flow question #9  
I know this post is old. I just bought a cat 257b from an auction. Can someone tell me how to know if it is high flow? And how do I find out what the gpm is? I don't know much about the machine, except how to drive it. I'm pretty good with that because I've had another skid steer before this one. The high and low speed is not seeming to work either, and I'm not sure what all the switches are for. I would get a service manual, but Cat told me they want $500 - $1000! Anyone know where it's cheaper? Any info would be great about any question! Thanks!
 
   / Cat 257B High Flow question #10  
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