How clean is your hydraulic system?

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Bandit1047

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Jan 13, 2008
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117
I just read an article in Equipment world that was a real eye opener on keeping your hydraulic system clean of particle, chemical and water contamination. (www.equipmentworlddigital.com/equipmentworld/200802/?) When I purchase attachments or rent attachments my first concern is the possability of fluid contamination. I normally do the best I can in draining as much fluid from attachments as possible, keeping in mind that you can not dry start a hydraulic motor without damaging it. Refilling is also a very opertune time to introduce contaminents into a system compounding the problem. Does anyone have any thoughts on this? Any solutions? I am going to research the possability of building a recirculation filtration system, any ideas would be appreciated. Joe
 

Tazza

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Dec 7, 2004
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The only way i have ever done it was to pop the return line connector off and open my hydraulics to push out the old oil into a waste bucket. Re-connect the coupler and away you go. There won't be a great deal in there but once purged just top up your oil tank. It only really works on gear with motors, as cylinders hold oil and you need to cycle them to get it out.
I have never understood dry starting a motor, if there is no hydraulic fluid it won't move in the first place, so how could it move? Thats what as always have me puzzled. Even if it did move a little, it would have oil residue still inside it to prevent damage.
 

OldMachinist

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May 24, 2006
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The only way i have ever done it was to pop the return line connector off and open my hydraulics to push out the old oil into a waste bucket. Re-connect the coupler and away you go. There won't be a great deal in there but once purged just top up your oil tank. It only really works on gear with motors, as cylinders hold oil and you need to cycle them to get it out.
I have never understood dry starting a motor, if there is no hydraulic fluid it won't move in the first place, so how could it move? Thats what as always have me puzzled. Even if it did move a little, it would have oil residue still inside it to prevent damage.
I never use rental attachments but a have thought some about this problem since it seems to come up often and it seems to me that if you used a lot attachments you may want to buy an extra set of couplers and a filter block to make a portable filter system and hook it to the return line of the attachment to catch any contamination before it can get in your machine. I know you may not be able to leave it hooked up while using some units but it would allow you to flush without making a mess or having to add fluid every time you flush. Just my 2 cents worth.
 

OldMachinist

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May 24, 2006
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I never use rental attachments but a have thought some about this problem since it seems to come up often and it seems to me that if you used a lot attachments you may want to buy an extra set of couplers and a filter block to make a portable filter system and hook it to the return line of the attachment to catch any contamination before it can get in your machine. I know you may not be able to leave it hooked up while using some units but it would allow you to flush without making a mess or having to add fluid every time you flush. Just my 2 cents worth.
Just one more thought. Make sure you buy a high pressure filter housing. They do make them that handle up to 3,000 psi. The normal spin on filters will not handle the full pressure of your system. High pressure filter housings are in the $160 to $200 range but that is cheap compared to a new pump or motor plus down time.
 

Tazza

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Just one more thought. Make sure you buy a high pressure filter housing. They do make them that handle up to 3,000 psi. The normal spin on filters will not handle the full pressure of your system. High pressure filter housings are in the $160 to $200 range but that is cheap compared to a new pump or motor plus down time.
Thats a good point but i always figure the chances of having contamination in the machine that used the attachment before you would be very slim. All machines do run filters to remove this and if they didn't they would quickly fail if dirt or metal particles got in the system. My main concern is the type of oil they ran, a filter won't be able to change that and even possible water contamination. There really is no way to purge all the oil from the attachment before use, but you can drain as much as possible for peace of mind.
With that said, i do remember Ken saying his brush mower was destroyed when he loaned it out and someone got dirt in the lines through the quick couplers. Dropping them in the dirt and NOT cleaning them is a quick way to kill an attachment and your machine. A filter would have surly saved the day here.
 

mllud

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Jun 29, 2007
Messages
635
Thats a good point but i always figure the chances of having contamination in the machine that used the attachment before you would be very slim. All machines do run filters to remove this and if they didn't they would quickly fail if dirt or metal particles got in the system. My main concern is the type of oil they ran, a filter won't be able to change that and even possible water contamination. There really is no way to purge all the oil from the attachment before use, but you can drain as much as possible for peace of mind.
With that said, i do remember Ken saying his brush mower was destroyed when he loaned it out and someone got dirt in the lines through the quick couplers. Dropping them in the dirt and NOT cleaning them is a quick way to kill an attachment and your machine. A filter would have surly saved the day here.
Joe
If you built something that you can plug your hoses into with a small tank to hold the oil out of the attachment. You could have a ball valve at the outlet.Start with tank empty,bleed out the air and incomes the fluid. when you start getting fluid. your flushed.
If you found one of those old canaster filter housings with the drain on the bottom to drain old oil.Then your ready for the next time. Ive seen some of those fairly large. you wouldnt need the filter in the housing.
Mike
 

skidsteer.ca

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Jan 20, 2006
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Joe
If you built something that you can plug your hoses into with a small tank to hold the oil out of the attachment. You could have a ball valve at the outlet.Start with tank empty,bleed out the air and incomes the fluid. when you start getting fluid. your flushed.
If you found one of those old canaster filter housings with the drain on the bottom to drain old oil.Then your ready for the next time. Ive seen some of those fairly large. you wouldnt need the filter in the housing.
Mike
I try not to worry too much about this, I go out of my way to get the quick couplers clean. Rinse them off with brake cleaner and wipe dry.
As for the oil, its pretty tough to get it all out, you can get 90% of it out of a continuos flow attachment, but you will never get it all out of an attachment with cylinders. On a continuos flow attachment you could put a low pressure return line filter in the out flow to protect your loader if you want.
I don't rent my brush cutter anymore, but I also put a high pressure filter in the pressure line on the attachment to catch any dirt that may get in the sytem or any wear that comes from the skidsteer.
However most filters (high pressure and return) have a bypass valve, so unless you warm the oil buy running the attachment slowly, you may open the bypass and allow some oil to bypass the filter until it thins enough from warming to flow through the filter quickly.
I only way to avoid this is to have all your own attachments. Even then you can have the pump going on your loader and wipe out the motor on your attachment. Or the motor wearing out on your attachment and contaminating your loader.
I do believe in filters, the more the better, also change your hyd oil and keep a eye on it for water contamination. Keep you oil cooler clean and monitor the oil temp.
If your really fussy you can have you oil sampled by Caterpillar (and others I'm sure) and see if it contains anything it should not.
If you run equipment long enough, you will have a failure.
Ken
 

perry

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Joined
Aug 22, 2006
Messages
869
I try not to worry too much about this, I go out of my way to get the quick couplers clean. Rinse them off with brake cleaner and wipe dry.
As for the oil, its pretty tough to get it all out, you can get 90% of it out of a continuos flow attachment, but you will never get it all out of an attachment with cylinders. On a continuos flow attachment you could put a low pressure return line filter in the out flow to protect your loader if you want.
I don't rent my brush cutter anymore, but I also put a high pressure filter in the pressure line on the attachment to catch any dirt that may get in the sytem or any wear that comes from the skidsteer.
However most filters (high pressure and return) have a bypass valve, so unless you warm the oil buy running the attachment slowly, you may open the bypass and allow some oil to bypass the filter until it thins enough from warming to flow through the filter quickly.
I only way to avoid this is to have all your own attachments. Even then you can have the pump going on your loader and wipe out the motor on your attachment. Or the motor wearing out on your attachment and contaminating your loader.
I do believe in filters, the more the better, also change your hyd oil and keep a eye on it for water contamination. Keep you oil cooler clean and monitor the oil temp.
If your really fussy you can have you oil sampled by Caterpillar (and others I'm sure) and see if it contains anything it should not.
If you run equipment long enough, you will have a failure.
Ken
Ken is on the money, I buy NAPA brake cleaner by the case and clean all four connections before hook up. As for loaning or renting equipment...NEVER
 

Eric

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Joined
Jan 19, 2005
Messages
169
Ken is on the money, I buy NAPA brake cleaner by the case and clean all four connections before hook up. As for loaning or renting equipment...NEVER
Somebody needs to design an attachment condom! Just kidding.
Bobcat now has an oil analysis program. I think the kit costs $16 and you mail it in. Then you go to a website and see the results.
 
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