changing/flushing hydraulic fluid from lines on dump trailer

[hawkeyestoob]

I have a 5X10 dump trailer that the pump started leaking badly on when it had any type of load on it last week. After some research I have ordered an entire new pump, motor and reservoir assembly for it that should be a direct bolt in replacement. How do I best get as much of the current hydraulic fluid out of the system before I install the pump assembly? Or am I overthinking this and as long as the current fluid is good looking with no particles in it should I just top off the reservoir with a good quality fluid, cycle everything a few times and go?

This is not used commercially but will see a good deal of use in the next few months as I finish grading my yard and will be moving dirt and mulch around.

Thanks,
Craig

 

[larry_g]

Hydraulic lesson learned today

I have a large 14k dump trailer. This trailer has its own battery powered hydraulic system. A year or so back The battery was way low and when lowering the bed it over run the pump and forced hydraulic fluid out the tank vent. So I topped it up with some AW-46 hyd fluid I use in a lot of the...

www.garagejournal.com

In my thread above I relate my experience with my dump trailer. Suggest you read it.

lg
no neat sig line

 

[hawkeyestoob]

Hydraulic lesson learned today

I have a large 14k dump trailer. This trailer has its own battery powered hydraulic system. A year or so back The battery was way low and when lowering the bed it over run the pump and forced hydraulic fluid out the tank vent. So I topped it up with some AW-46 hyd fluid I use in a lot of the...

www.garagejournal.com

In my thread above I relate my experience with my dump trailer. Suggest you read it.

lg
no neat sig line

Thanks Larry. That is some excellent information. Unfortunately the manufacturer of my trailer is no longer in business and the original paperwork does not indicate what type of fluid they used. It is 10 years old and from day one I have thought the fluid smelled like ****** fluid which I know is common. I ma also hopeful that because of it's age that they would not be using the water based fluid. Since it is only a single cylinder trailer worse case pumping the new fluid through and catching what runs out would not be the most terrible thing in the world.

 

[Sumboodie]

Aw-46 is too thick unless you live somewhere that doesn't get cold.

I'd use ATF or an ISO 15 hydraulic oil.

Water based hydraulic oil? Never heard of that. The customers I service work out in places like ANWR and use normal oil.

 

[mike93lx]

At 10 years old I think I would take the opportunity to put new fluid in it

 

[hawkeyestoob]

At 10 years old I think I would take the opportunity to put new fluid in it

That is where I am. It has lived a very easy life but while I have it apart I figure I should flush out what is in the lines as good as reasonably possible and add some fresh hydraulic fluid.

Any tips on how best to flush something like this?

 

[larry_g]

That is where I am. It has lived a very easy life but while I have it apart I figure I should flush out what is in the lines as good as reasonably possible and add some fresh hydraulic fluid.

Any tips on how best to flush something like this?

Is this a single or double acting cylinder? My thread I linked to above outlines the procedure I used on my double acting cylinder near the end of the thread.

lg
no neat sig line

 

[hawkeyestoob]

Is this a single or double acting cylinder? My thread I linked to above outlines the procedure I used on my double acting cylinder near the end of the thread.

lg
no neat sig line

My trailer is a DA single cylinder.


I saw that in your thread and that is what got me thinking about how exactly I would remove all of the existing fluid. I am thinking that I might just take all the the fittings and let gravity get most of what is in the cylinder out. A little compressed air to the lines should get the majority of it out there.

 

[PCustoms]

My trailer is a DA single cylinder.


I saw that in your thread and that is what got me thinking about how exactly I would remove all of the existing fluid. I am thinking that I might just take all the the fittings and let gravity get most of what is in the cylinder out. A little compressed air to the lines should get the majority of it out there.

Was going to suggest this.

In reality as long as you use compatible fluid you don't need to get it all out. This have a filter?

 

[hawkeyestoob]

Was going to suggest this.

In reality as long as you use compatible fluid you don't need to get it all out. This have a filter?

No filter on the system unless there is a screen on the intake side of the existing pump.

I figure that gravity and a little coaxing will get enough of the fluid out that I will be OK. If I get ambitious I can always raise and lower the bed with by front end loader to help push the fluid in the cylinder out.

 

[AA/FC]

I would run ATF. That is what most of those types of universal 12 volt hydraulic pumps use. In fact, I've never seen anything but ATF used in that type of pump.

As for fluid change, unless the system got water in it, or you ruined a pump and contaminated the fluid with metal bits and pieces, the fluid really doesn't go bad in that type of application. It never gets hot enough, for long enough to cook the fluid, and it's not like engine oil where it gets cooked and full of carbon, etc, etc... If the fluid looks good, it's probably good. However, if you're in there doing a pump change anyway... then sure, change the oil. And don't kill yourself trying to get every last drop of old oil removed from the system. Dump whatever you can and let 'er rip with the new stuff!

In fact, looking at the link you provided in post number 1, under the "installation" tab on that page you can click on a PDF called "installation manual" and on page two of that document it shows the recommended hydraulic oil..... ATF or ISO 15 is the recommended oil for the pump you just bought. I'd use ATF.... it's easy to get anywhere.

Edit:
This is the link to the installation manual that I found at the link you provided to the new pump you recently purchased. I will paste it here to make it easy for everyone to find.
http://cdn.premium-supply.com/KTI_Docs/double-acting-pump-manual.pdf

 

[Steve_P]

It's very doubtful that it's some type of water-based fluid, but I'd assume there would be an easy way to verify that by trying to boil or freeze some, or similar.

Some specialized hydraulic systems do use conditioned water as a fluid because they cannot allow for an oil leak in that location. And hydraulic systems eventually leak via a failed hose or fitting. We had some tube fittings catastrophically fail which made a huge mess, thankfully it was water as the fluid. They were a reputable brand fitting, and were replaced with Swagelok and no more issues.