Hydraulic Fluid Mystery

[Mr. Clean]

For the second time in the last three weeks the site glass on the hydraulic pack reservoir indicated low fluid level at morning start-up. Thorough inspection found no leaks. After washing several vehicles the level rose about a quarter inch on the glass w/o having added any fluid. Where and why is oil being sequestered? Temperature expansion/contraction causing the variation?
Thanks.
MC

 

[under pressure]

I was thinking temp variation, before i was done reading your post, keep an eye on it tho

 

[Mr.Aap]

Gets warm and expands....

 

[Mr. Clean]

The level doesn't seem to fluctuate with temp. Came in yesterday morning and it was on the mark before any anything got washed. Reservoir tank was at ambient temp. ~ 60 degrees. No change throughout the day

 

[MEP001]

Hydraulic fluid does expand and contract with temperature changes. Perhaps it was colder during the nights when it was found to be low. In any case, since it comes back up to a normal level it appears to be a non-issue.

 

[mac]

There are some things in life that man is not meant to understand.

 

[Chuck Ivey]

There are some things in life that man is not meant to understand.

Truer words have never been spoken Mac.

 

[Chiefs]

You may or may not have a leak, but have you put any dye into the hydraulic oil? A red dye will help you diagnose a small leak before it becomes a big one. An ounce of prevention....

 

[MEP001]

You may or may not have a leak

If the fluid level returns to normal without adding more, there's obviously no leak.

 

[Chiefs]

I was not intimating that he did have a leak, but just to pass on a tip that makes leaks easy to find and able to detect far more quickly than waiting for a catastrphic failure. If you don't have due in the fluid leaks are much harder to detect.

 

[packerscw]

Definitely cant be a leak if the fluid level is changing on its own

 

[JimmyJaffa]

Check your sight glass, for what you are saying, the most likely problem. Clean out where the lines go through the tank. Both bottom and Top!