saw mill hydraulics

/ saw mill hydraulics #1  

rasorbackq

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Aug 31, 2011
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Location
Springfield Nova Scotia Canada
Tractor
Branson 4720
I am a pretty smart guy but when it comes to hydraulics I really know zero.
I have a home made saw mill that I bought . It has hydraulic cut as well blade lift. So this week it was cold out below zero . Saw has sat unused for a month or 2 . Took a boost to get the saw going and then the hydraulics didn't work. The 20 hp honda belt turns a pump which has 2 ccts . One lift and one for run. Neither worked so I thought it was frozen someplace. I popped the tank cap to see the ATF (pink stuff thought the last owner told me that's what he had in there) was pink and all foamy looking. Would have thought the ATF would look like it was pink and clear . I am thinking that It maybe got water in or condensation from the last couple years . Calling for 8 deg C tomorrow and will see if it all works again. If it does I will need to replace the fluid . Any thought ??
 
/ saw mill hydraulics #2  
I think I would replace the ATF and look for a suction leak, which would make the fluid foamy or entrained air bubbles.

Put a heat gun on the valve and hoses to help the fluid flow until you change it out.
 
/ saw mill hydraulics #3  
Hydraulic tools need to breathe a lot, so they often get water in the oil when left outside.
Some ice in the oil could cause some problems, yes. If you see foam, something is
sucking air, and that could be unrelated to the cold temps.

I am planning a bandsaw mill that uses hyd drive for the carriage only. Is yours
a circular saw or bandsaw?
 
/ saw mill hydraulics
  • Thread Starter
#4  
Hydraulic tools need to breathe a lot, so they often get water in the oil when left outside.
Some ice in the oil could cause some problems, yes. If you see foam, something is
sucking air, and that could be unrelated to the cold temps.

I am planning a bandsaw mill that uses hyd drive for the carriage only. Is yours
a circular saw or bandsaw?

Bandsaw mill
+6 outside now so will work on the saw today in the rain.
 
/ saw mill hydraulics #5  
ATF is a very good low temp oil to use. if you have water in the fluid it will turn it light pink and freeze up the hydraulics. this is more than likely your problem. This weekend should be warm enough to get it turning... 20 below is no fun... if it works then drain the oil and replace it, it will take several tries to get all the water out. if you can get some of the oil out of the tank you can do a crackle test for water. Monitor Water-In-Oil with the Visual Crackle Test
for a suction side air leak , this will cause the oil to foam after you use the machine for some time. check all the fillings from the tank to the suction side of the pump, check around the shut off valve on the tank (if you have one) and around the suction filter/screen (if you have one)
 
/ saw mill hydraulics
  • Thread Starter
#6  
So ran the saw today and the hydraulics work but as soon as I used them the reservoir over flowed with light pink foam and fluid. After I removed the cap all over flow stopped. I see there is a drain on the bottom but how does one get the fluid out of the lines.
Run the saw and pump them out?
Ii am thinking if I had a air leak would the saw leak fluid when the pump is turning?
 
/ saw mill hydraulics
  • Thread Starter
#7  
ATF is a very good low temp oil to use. if you have water in the fluid it will turn it light pink and freeze up the hydraulics. this is more than likely your problem. This weekend should be warm enough to get it turning... 20 below is no fun... if it works then drain the oil and replace it, it will take several tries to get all the water out. if you can get some of the oil out of the tank you can do a crackle test for water. Monitor Water-In-Oil with the Visual Crackle Test
for a suction side air leak , this will cause the oil to foam after you use the machine for some time. check all the fillings from the tank to the suction side of the pump, check around the shut off valve on the tank (if you have one) and around the suction filter/screen (if you have one)

I will try the crackle test. Not sure if I can get a hotplate to 160 though.
 
/ saw mill hydraulics #9  
Flush with more ATF.

Blow the lines with air.

Use heavy duty tin foil or a spoon and a lighter or torch.

You might never see a suction leak. Just the results.

Just tighten up all the hoses.
 
/ saw mill hydraulics #10  
we just use the corner of an aluminum snow shovel (don't know where we would find one up here ...LOL) put a cup of oil in the corner and use a propane torch to heat the under side (do this out side) the oil will heat up and if you see any bubbles or hear crackling from under the flame then you have water, pure oil will just heat up and not bubble/crackle Jim
 
/ saw mill hydraulics
  • Thread Starter
#11  
we just use the corner of an aluminum snow shovel (don't know where we would find one up here ...LOL) put a cup of oil in the corner and use a propane torch to heat the under side (do this out side) the oil will heat up and if you see any bubbles or hear crackling from under the flame then you have water, pure oil will just heat up and not bubble/crackle Jim
So Jim what you are saying is my plastic snow shovels not going to cut it?
 
/ saw mill hydraulics #13  
A problem with ATF is that it absorbs/attracts moisture In a normal automatic transmission this usually is not an issue since there isn't constant air movement in and out like there is on most hydraulic systems due to cylinders moving.
 
/ saw mill hydraulics
  • Thread Starter
#14  
So did the crackle test today Failed badly. The water in the ATF just about jumped out of the spoon Blew out all lines . Is there a certain filter that I need to install . Will any filter work?? as long as it will screw on?
Guess I am curious about filters as to why there are so many different sizes for cars.
 
/ saw mill hydraulics #15  
There are hyd filters that will remove a little water.

Best thing is to drain and refill.
 
/ saw mill hydraulics
  • Thread Starter
#16  
Thought that if I got a new filter it would be the best way to get rid of any water in the filter.

HPIM3061.JPGHPIM3062.JPG
 
/ saw mill hydraulics #17  
You should have a drain at the lowest part of the hyd system, and if any water gets in, and not emulsified, you can turn a small valve and drain off the water.

Ones the fluid has been emulsified, you need to replace it, and clean the system. All of the surfaces will be covered.

Also, once the fluid has been emulsified, the mix will develop new compounds, not good for the hyd system.

Looking st your system, it looks like the lowest point of the hyd system is the suction hose, and that is where any free water will collect or freeze.
 
/ saw mill hydraulics #18  
Rasor.. like Jj said, it's best to dump all the oil out you can, replace it with new, then add a water sorb filter, you can get a Stauff sf-6520W filter or any other with water sorb, run it for several hours then replace the filter again with another one. you can use water sorbs all the time if you want.. i think Thursday will be a GREAT day to work on it outside... should be a nice balmy 22 below.... jim
 
/ saw mill hydraulics
  • Thread Starter
#19  
Whole system has been drains . My plan was to fill up the reservoir and let it gravity flow out to clean up the walls Not sure how much ATF can be inside the pump and 2 drive gear boxes but I did get out all I could with the air hose . Will check today at Can tire for a filter . The ATF looks just like Pepto-bismol
 
/ saw mill hydraulics #20  
The next tankful may look similar.
 
 
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