Hydraulic Fluid

[David Fischer]

I have a C12 Cat engine and the  hydraulic  fluid is showing a little low and I used up my old bottle of fluid and thru out the bottle.  Just some conformation from anyone would help.  It seemed I used Dextron transmission fluid for the hydraulic tank, but not too sure.  It sounds silly, but I just want to be sure.  

[Bill Sprague]

My Beaver Lubrication book specifies Dextron III.  I don't know what the III is about.

[Gerald Farris]

David,
The 1997 Marquis used Dextron III transmission fluid in the hydraulic system. If you change the hydraulic fluid in your system when replacing the hydraulic filter, you may want to consider changing it over to TranSyn instead of the Dextron III. TranSyn is more expensive, however it lubricates better and is more heat tolerant than Dextron III.

Gerald  

[Richard And Babs Ames]

You also do not have to flush out the system as Transynd and Dextron III are compatible.

[David Fischer]

Thank you all for your help.  I have never changed the Hydraulic fluid in the coach so I will have to look up in the Gillig book as to how to do it.