Question about hyrdaulics

[rasorbackq]

In late summer we bought a Band saw Mill . It has hydraulic lift and cut. Is there something I have to do use it during the winter months ? Noticed the other day when below zero the travel portion of the saw was not moving with the level in the direction of the cut.
Today the temps are -5 and the saw up and down was slower then norm and the travel didn't move. I heated the valve with a hand torch and then it began to move .
Not sure if water has gotten in and formed ice or if the fluid is just cold. The travel portion of the saw in just a hydraulic pulley with a cable wrapped about to shuttle it along.
Would like to use it the winter but its just getting cold now and I am having problems.

 

[rasorbackq]

Was just looking at the valve Seems its boot is all cracked. Handle movement is not the same as the up down handle.
Can these boots be replaced?

 

[J_J]

Have you considered changing out the fluid to ATF.

You could also put a magnetic heater on the bottom of the reservoir.

You could also hold the lever in relief until the fluid is warm.

Maybe put an insulated box/blanket over the reservoir and pump.

Show us some pictures.

 

[Zebrafive]

You need some way of warming the hydraulic fluid.

 

[wdchyd]

Warming the hyd oil before opertating is best, adding low-temp aircraft oil is good for equipment that doesn't run continuously (ie: elec plow pump, scissors lift ect)

the problem with low-temp oil is it is very thin, which is not very good for lubricity for the hyd pump when the hyd oil heats up or using for summer use

warming the oil can be done by adding a diverter valve inline between the pump and control valve, then off the new leg deadhead a pressure relief valve (preset at 1/2 to 3/4 of your existing PRV on the control valve) and return the excess flow back to tank.........the constant blowing over the relief valve will heat up on it's own, warming the oil going into the reservoir.........kinda like leaving the 3ph lever in the up position when starting/warming up your tractor, same effect

Before doing anything further best to check to make sure their is no water/milky oil in the system.....many times the water in the oil sluges up in the freeze cycle and causes havoc

 

[J_J]

I envision a Band Saw mill using a small amount of hyd fluid, I would drain and replace with ATF. It has a very wide temp range.

You might change the location of your hyd valve so water can not get in the spools, or cover sufficiently.

What is the size of your hyd tank.

If you are concerned about the temp in summer, place a temp gage in the tank and monitor the temp. Up to about 200 degrees.

How often do you use the saw.

 

[rasorbackq]

Have you considered changing out the fluid to ATF.

You could also put a magnetic heater on the bottom of the reservoir.

You could also hold the lever in relief until the fluid is warm.

Maybe put an insulated box/blanket over the reservoir and pump.

Show us some pictures.

I am unsure as to what ATF fluid is . I have seen it but never really looked at the jug.
The heater for the reservoir ........ how is that powered and where can they be purchased?
Will get some pics today.

Quote...Before doing anything further best to check to make sure their is no water/milky oil in the system.....many times the water in the oil sluges up in the freeze cycle and causes havoc How does one do this check? From the reservoir????

 

[J_J]

ATF is Automatic Transmission Fluid.

Magnetic block heaters can be found at any auto parts store.

Drain a quart of fluid from the reservoir and sit out in the cold and then see what the flow characteristic are.

Testing for water. Place a couple of drops of fluid on a heated surface, and if it crackles, it has water in the fluid.

 

[rasorbackq]

I envision a Band Saw mill using a small amount of hyd fluid, I would drain and replace with ATF. It has a very wide temp range.

You might change the location of your hyd valve so water can not get in the spools, or cover sufficiently.

What is the size of your hyd tank.

If you are concerned about the temp in summer, place a temp gage in the tank and monitor the temp. Up to about 200 degrees.

How often do you use the saw.

Don't know much about hydraulics as you will see but didn't know there was an issue with the fluid getting hot. Guess the saw engine runs for 15-20 minutes to make the cuts on one tree. The pump not sure if its moving fluid during the time or just during the level operation. The cut portion runs for maybe 1 minute and then log is rotated to make next cut. Lets say 1 minute one 2-3 minutes off.
Did find some replacements boots for the levels.
Both the up and down and cut controls are BM 30s.
Will get some pics today . as the temps will be just above zero this week. Will have to get all the work done there if I want to saw this winter.

 

[J_J]

If the hyd system is an open center system, the fluid is flowing as long as the engine is running .

Fluid temp running much over 180 will deteriorate.

Excerpt:

Hydraulic Fluid Temperature

How hot is too hot? Hydraulic fluid temperatures above 180°F (82°C) damage most seal compounds and accelerate degradation of the oil. While the operation of any hydraulic system at temperatures above 180°F should be avoided, fluid temperature is too high when viscosity falls below the optimum value for the hydraulic system’s components. This can occur well below 180°F, depending on the fluid’s viscosity grade.

Solving Hydraulic System Overheating Problems