Foamy hydraulic oil, want to add 10w-30?

[bdryer]

OK. So i think i know what my problem is. I used the cheapest hydraulic oil i could buy at Walmart. Super Tech i think its called. Now i have foam. it foams right out the filler tube and the hydraulics are slow. I now look at the manufacture specifications and it says use 10w-30 motor oil instead, ok, so if i drain the reservor and fill it with 10w-30 is that going to be a problem? the fact that they will be mixed? Thanks for the help

 

[jerry]

I really doubt that the oil is the problem. The hydraulics are slow because of the air in the oil which you do not want as it will cause damage. Mixing the two oils will not hurt and is almost unavoidable even with draining the tank. Find the air leak first, under the fender where the hoses are routed to the boom cylinders there are short metal tube lines and one of them started leaking on my 665 . I replaced it but it was hard to locate till it started leaking bad. I haven't looked but have read that there are metal tubes down in by the belly pan that wear through sometimes also. How did you end up with the Wal-mart oil, was it a normal oil change or was the oil level down a lot from a leak?

 

[Planenut99]

I really doubt that the oil is the problem. The hydraulics are slow because of the air in the oil which you do not want as it will cause damage. Mixing the two oils will not hurt and is almost unavoidable even with draining the tank. Find the air leak first, under the fender where the hoses are routed to the boom cylinders there are short metal tube lines and one of them started leaking on my 665 . I replaced it but it was hard to locate till it started leaking bad. I haven't looked but have read that there are metal tubes down in by the belly pan that wear through sometimes also. How did you end up with the Wal-mart oil, was it a normal oil change or was the oil level down a lot from a leak?

A few more places to look for leaks that will cause foaming. The two seals on top of the hydrostatic pumps where the input shafts connect, & if there are any signs of leakage in between the pumps. The "case drain" system for the hydrostatic pumps and motors all actually operate at a negative pressure. Check all of the metal lines and hoses in this drain system for being tight. They don't always leak oil.

 

[bdryer]

I really doubt that the oil is the problem. The hydraulics are slow because of the air in the oil which you do not want as it will cause damage. Mixing the two oils will not hurt and is almost unavoidable even with draining the tank. Find the air leak first, under the fender where the hoses are routed to the boom cylinders there are short metal tube lines and one of them started leaking on my 665 . I replaced it but it was hard to locate till it started leaking bad. I haven't looked but have read that there are metal tubes down in by the belly pan that wear through sometimes also. How did you end up with the Wal-mart oil, was it a normal oil change or was the oil level down a lot from a leak?

The level was down from the leak / foaming. I put the 10W-30 in and same problem. I guess i will start looking for a leak per your recommendations. Thanks. More to follow.

 

[bdryer]

The level was down from the leak / foaming. I put the 10W-30 in and same problem. I guess i will start looking for a leak per your recommendations. Thanks. More to follow.

Been looking for leaks but have not found any yet. I found a hose that had a bad worn spot on it so i replaced it thinking it was the problem. $70 dollars for hose and didnt do a damn thing. worked on it today for a while and noticed something that might be an indicator of the problem. I checked the oil level in the tank and it was right were it was supposed to be, started it up and let it idle for a couple on minutes, could not see the oil level any more so i stuck a 3' hose down the tank to check the level and found the oil to be foamy. i didnt do anything but start the engine. What does that tell me?????

 

[jerry]

Been looking for leaks but have not found any yet. I found a hose that had a bad worn spot on it so i replaced it thinking it was the problem. $70 dollars for hose and didnt do a damn thing. worked on it today for a while and noticed something that might be an indicator of the problem. I checked the oil level in the tank and it was right were it was supposed to be, started it up and let it idle for a couple on minutes, could not see the oil level any more so i stuck a 3' hose down the tank to check the level and found the oil to be foamy. i didnt do anything but start the engine. What does that tell me?????

If you turn your air compressor down to about 10 lbs and wrap something around the blow gun and so you can stick it in the fill opening and pressurize the hyd tank it may show if you have a loose clamp where it is sucking air but not leaking oil out? works sometimes on things sometimes doesn't but it won't hurt. Suck out a small jar of the oil and see if you agitate it if it foams. You may have to sneak the egg beater or blender from the house to do it though.