Skip to main content ↑ ↓
Topic: Power steering oil tank.. oil looks "milky"!!!!! (Read 743 times) previous topic - next topic

Power steering oil tank.. oil looks "milky"!!!!!

What Broke???  Looks like water in the oil

Re: Power steering oil tank.. oil looks "milky"!!!!!

Reply #1 –
I was working on a coach several years ago and saw milky looking oil in the reservoir. I drained it changed the filters and then ran it with the return line into a bucket until it was clear. I have no idea why it was like that.

Re: Power steering oil tank.. oil looks "milky"!!!!!

Reply #2 –
Have you confirmed the INSIDE content is milky vs oil leaking out of the lid gasket and contacting water on the outside?

Re: Power steering oil tank.. oil looks "milky"!!!!!

Reply #3 –
Quote from: wolfe10 –
Have you confirmed the INSIDE content is milky vs oil leaking out of the lid gasket and contacting water on the outside?
Yup, pulled the dip stick and the oil is milky.. May be part if the story on why the steering is kinda herky jerky..
Question is ..is there a water/oil cooler (radiator) on this system? Trying to follow the oil lines is a challenge from the tank to the oil pump to the hyd fan motors and then forward to steering pump.
We had the radiator and air to air rebuilt 2 years ago @ Cummins..

Re: Power steering oil tank.. oil looks "milky"!!!!!

Reply #4 –
Quote from: red tractor –
I was working on a coach several years ago and saw milky looking oil in the reservoir. I drained it changed the filters and then ran it with the return line into a bucket until it was clear. I have no idea why it was like that.
Did it ever "repeat"

Re: Power steering oil tank.. oil looks "milky"!!!!!

Reply #5 –
The hyd oil is air cooled. With the system pressurized I don't know how a seal leak could admit water. I don't think the tank is pressurized and if the cap had water getting to by it from heavy rain a possibility but not likely. Let us know what the outcome is on this one it's new to me.

Re: Power steering oil tank.. oil looks "milky"!!!!!

Reply #6 –
Air from cavitation when you come to the limits either left or right and the pump cavitates. Here is the skinny: Cavitation or Aeration? How to Tell the Difference  This is a common condition and happens all the time. Just pour a little milky oil in a glass and it will be clear in a few minutes. That's what the nasty noise in the PS pump is. In a water pump, it can chunk off pieces of the pump.

Pierce

Re: Power steering oil tank.. oil looks "milky"!!!!!

Reply #7 –
Condensation?

Re: Power steering oil tank.. oil looks "milky"!!!!!

Reply #8 –
Quote from: craneman –
The hyd oil is air cooled. With the system pressurized I don't know how a seal leak could admit water. I don't think the tank is pressurized and if the cap had water getting to by it from heavy rain a possibility but not likely. Let us know what the outcome is on this one it's new to me.
That is what I thought, but the dip stick for the  tank is not pressurized..
 I followed the oil lines to the  cooler behind the radiator. .
I mean..... it is a closed circuit system.. got me flummoxed  .
The only other thing I can think of is that the Power steering/radiator fan motor(s) oil pump  is injecting (cavitating)air into the oil..  OR.......Hmmmm.... The filter is kaput?? Just checked my receipts from Cummins and Foretravel and DO NOT see that the filter has ever been changed....

Re: Power steering oil tank.. oil looks "milky"!!!!!

Reply #9 –
Quote from: Pierce & Gaylie Stewart –
Air from cavitation when you come to the limits either left or right and the pump cavitates. Here is the skinny: Cavitation or Aeration? How to Tell the Difference  This is a common condition and happens all the time. Just pour a little milky oil in a glass and it will be clear in a few minutes. That's what the nasty noise in the PS pump is. In a water pump, it can chunk off pieces of the pump.

Pierce
Very True on systems that use ATF fluid..Ours uses 15/40 engine oil.. but even then I have seen cavitation issues in other systems.

Re: Power steering oil tank.. oil looks "milky"!!!!!

Reply #10 –
Air entering the system and causing the microscopic bubbles is Aeration. Cavitation is when a positive displacement pump can't get enough oil/fluid/etc on the suction side and the pressure drops creating a vacuum,  essentially boiling the fluid and creating tiny bubbles. The warmer the fluid, the more bubbles will be created. The noise you hear is the bubbles being created. It can damage a pump if it goes on too long or very frequently. The more bubbles created, the less efficient the pump is until it may fail to pump at all.

This frequently happens to fire trucks when the discharge is greater than the supply hose(s) can provide. Propellers on boats can also suffer the same effect.

Difficult to get your head around bubbles being created this way. Here are several video examples of the cause. https://www.youtube.com/results?search_query=cavitation

Pierce

Re: Power steering oil tank.. oil looks "milky"!!!!!

Reply #11 –
Put a sample of the oil in a clear glass and let it sit overnight then see what it looks like.

Re: Power steering oil tank.. oil looks "milky"!!!!!

Reply #12 –
Quote from: Pierce & Gaylie Stewart –
Air entering the system and causing the microscopic bubbles is Aeration. Cavitation is when a positive displacement pump can't get enough oil/fluid/etc on the suction side and the pressure drops creating a vacuum,  essentially boiling the fluid and creating tiny bubbles. The warmer the fluid, the more bubbles will be created. The noise you hear is the bubbles being created. It can damage a pump if it goes on too long or very frequently. The more bubbles created, the less efficient the pump is until it may fail to pump at all.

This frequently happens to fire trucks when the discharge is greater than the supply hose(s) can provide. Propellers on boats can also suffer the same effect.

Difficult to get your head around bubbles being created this way. Here are several video examples of the cause. https://www.youtube.com/results?search_query=cavitation

Pierce

Yup, have fought both conditions in the past.... Am thinking that the oil filter is plugged up and causing the pump cavitation)
Will see if I can get it into a shop after Infinity gets their stuff completed.... Going to try Red Tractor's solution  first..( pull  the filter then pull return line and put into a bucket, keep filling  tank  while running the engine until the fluid runs clear,replace the filter with new & top off)....Also will temporarily disconnect the controller for the radiator fans (put into high speed default mode)to insure that any contaminates in those lines are also flushed out....

Re: Power steering oil tank.. oil looks "milky"!!!!!

Reply #13 –
In answer to your question the problem did not repeat. After letting the oil set over night it was still milky plus it had set for several days before I noticed it. We had some really heavy rains ahead of this but the tank was not over full. Still a mystery to me.

Re: Power steering oil tank.. oil looks "milky"!!!!!

Reply #14 –
Quote from: red tractor –
In answer to your question the problem did not repeat. After letting the oil set over night it was still milky plus it had set for several days before I noticed it. We had some really heavy rains ahead of this but the tank was not over full. Still a mystery to me.
Yup same here.. fluid level right where it should be.. thinking a plugged filter, causing the pump to cavitate.
Hope i can find someone that can get to it soonest..

Re: Power steering oil tank.. oil looks "milky"!!!!!

Reply #15 –
If you have the following, this is a VERY easy DYI job:

5' or cheap, clear PVC hose to siphon out the old oil.
The 3 filters.
Top gasket
New oil.

Re: Power steering oil tank.. oil looks "milky"!!!!!

Reply #16 –
Quote from: wolfe10 –
If you have the following, this is a VERY easy DYI job:

5' or cheap, clear PVC hose to siphon out the old oil.
The 3 filters.
Top gasket
New oil.
Yup.. Could do .. however We are full timers so no place to do it at, so going to plan "B"... Should be pretty straight forward.

Re: Power steering oil tank.. oil looks "milky"!!!!!

Reply #17 –
Saddle,where are you?,maybe one of us nearby to help,it's time consuming but save some of the milky stuff and get an oil
analysis.

Re: Power steering oil tank.. oil looks "milky"!!!!!

Reply #18 –
Maybe someone pressure washed the back engine bay, and water got into tank?

Chris
 

Re: Power steering oil tank.. oil looks "milky"!!!!!

Reply #19 –
Quote from: gracerace –
Maybe someone pressure washed the back engine bay, and water got into tank?

Chris

Yes, particularly if the lid gasket is compromised.  Good catch.