On Fri, 02 Oct 2015 10:57:06 -0700, wrote:

On Thu, 1 Oct 2015 06:22:23 -0700 (PDT), wws
wrote:

On Wednesday, September 30, 2015 at 7:03:21 PM UTC-5, wrote:
I am going to be replacing the hydraulic pump on my Case 580 CK
backhoe this winter. Some time back the hydraulics heat exchanger in
the radiator leaked. This leak led to lots of oil in the water and a
some water in the oil. I fixed the problem by bypassing the internal
heat exchanger and then drained the coolant and hydraulic oil from the
machine. So after new coolant, new oil filters, and new hydraulic oil
all seemed well. After a few years the oil pressure dropped, a gradual
process, to the point where I knew there was a problem. It turns out
the pump is worn out. Checking the pressure where the Case manual says
to check it affirmed my suspicion that the pump is worn. So it will
either be repaired by me or replaced. It also turns out that I did not
get all the water out of the hydraulics. I think this may be why the
pump wore out. Even though the oil looked clear after I drained and
refilled the system I apparently didn't do it right because now the
oil is milky. There is no way for water to enter the system now except
by through the breathers and I run the machine long enough to get the
oil hot enough that this shouldn't be a problem. Speaking with my
neighbor who is a retired backhoe operator who owned his own business
about this I was told that I did not get all the water out the first
time and that this was not unusual. Especially for someone with my
limited experience. So to avoid ruining a new pump I have a plan and
need advice.
First I will replace the filters (there are only two).
Second I will drain and replace the hydraulic oil.
Third I will replace the pump.
Fourth will be bleeding the system.
The advice I need is how to be sure I get all the water out of the
hydraulic system, how best to bleed the system, and is my order of
operations above correct? Should I try to get the system water free
before I change the filters? Or should I do as above but then change
the filters again after changing the oil and making sure it is free of
water?
Thanks,
Eric

http://www.machinerylubrication.com/...g-water-in-oil
This site has some good info. I like the vacuum method at only 28 in. hg.
Thanks, that is an interesting article. In my case though it doesn't
really apply except maybe the vacuum option when the oil is hot. This
is because the oil and water have formed an emulsion and even though
the oil has gotten plenty hot the water won't come out. When I say
plenty hot I mean as hot as it can get when operating the backhoe
during the hottest days we get here. If I had a vacuum pump I would
try pulling a vacuum on the oil reservoir when the oil is hot, then
letting the oil cool and try draining the reservoirs. Right now if I
draain any oil out it comes out milky. I guess this is a common
problem with hydraulic oil.

The million dollar question is "Will that reservoir stand up to a
pretty strong vacuum?" I'd sure as hell be hesitant if it were my
vehicle. Caveat Experimentor.

--
The human brain is unique in that it is the only container of which
it can be said that the more you put into it, the more it will hold.
-- Glenn Doman