Hydraulic Oil Replacement

[eray1066]

When is it time to replace hydraulic oil in a pt425? Tractor is 10 years old and never changed hydraulic oil, but replace hydraulic oil filter regularly. Oil is same color as the day it was bought but does not smell like fresh oil any more. Is this a problem? All hydraulics seem to work fine, no leaks.

If changing the oil, do all the lines/cylinders need to be bled, and how would this be done? What is the recommended weight (for hot climate) for the hydraulic oil? I have read 10W40 or 5W40 on posts.

Thanks,
-Tim

If you have ever had to split a tractor to replace a hydraulic pump (or two in some instances), you will change all the the oil and filters every year. $250 for oils and filters is way cheaper than a multi thousand dollar repair bill. That said, it is still painful to see all that seemingly clear oil draining out of the tractor.

[BobRip]

I talked to Keith at Power Trac and he said that with me using Mobil 1 that a change was not needed for a long time even with my 12 year old PT 422.. I am sorry but I did not ask the broader question of using regular oil. Call Keith. He is always very helpful.