That is the way to do it... Did you keep the hydraulic oil topped off, (don't overfill), as you ran the air out? May take 5 min forward and reversed while it is jacked up. Engine at idle...
Check the idler pulley on the drive belt... the spring can be weak and allow it to slip and that may be the source of the sound...
:smile:KennyV
The cap is vented, but it would allow the air a quick exit with the top off... should not matter once air gets to the reservoir.
If it is air in the system , it may take a bit more time running with the drive wheels jacked up... run with No load. :smile:KennyV
Up just enough to clear the tires should do it...
Synthetic will blend with anything so that will not cause any problems. Synthetic is great for hydro use...
20w50 is the correct oil... continue with the air purge if you have already checked all the external possible sources for the noise... If you can post a short youtube with the sound recorded...
:smile:KennyV
Get a Scag filter of the correct part number. Bear in mind that when you remove the filter, the oil reservoir will drain out.
When I replace this filter I fill it up with oil and let it sit to soak and vent off the air, top off the oil and then install it. I then fill the reservoir to the level of the tube, run the machine, check and top off the reservoir. This minimizes the removal of air in the system which is usually very quick. You will need 3 quarts of 20W50 oil.
A vented hydraulic reservoir needs to have sufficient air space above the oil level to allow the returning oil to release the air bubbles, overfilling the reservoir will affect the release of the air bubbles and underfilling can cause cavitation of the oil being drawn in by the pumps.
Make sure the by-pass valves on each pump are shut, check you manual for location and tightness of these valves.
Mad Mackie in CT
I guess it's possible I overfilled slighty? (used 3 Qt including filter fill) I did use the correct Scag brand filter however it looks different than the original one I took off. Looking down at the holes on the filter there are crimps sort of hexagonally around the filter housing. The new one I just bought to replace the one I just put on :frown: (also Scag brand same #) is round with no crimps? I wonder if they have different manufacturers making their filters? I will check the bypass valves for tightness. Thanks for the tip. Are you saying that you fill just below the metal tube initially to bleed, then fill to specs? Should I leave the tube out when bleeding? Maybe I'll try and bleed again without the tube in see if that solves the problem. Thanks appreciate the help. Don't want to mess up my "new to me" Scag.