2 Hydraulic questions...fluid change and "speed"

[couchsachraga]

Greetings! I haven't found a good answer to this, so I'm hoping someone here can tell me. Two questions, both relating to my Powershift Yanmar 336D (uses JD type 303 trans hyrdraulic fluid):

1) I have a snow plow rigged up for it now, angles using tractors hydraulics. Works great. I have another, larger plow I'd like to use this winter...BUT it's cylinders have used the typical ATF most folks use in plow truck hydraulic systems. So, what should I do? Is there a way to clean them out? Or just get it set up, cycle through a few times, and then do a hydraulic oil change (due this fall anyway)? For the curious all I did was put 3ph "ears" on the plow with all thread to stabilize said ears, and use an old "A" frame from another implement to attach the top link to, and a chain goes from the top of the A frame to the plow. Works great, though I do end up plowing in reverse.

2) Same tractor...this time the other end (front loader) - when I go from extending to retracting a cylinder under pressure there is a several second time lag - in other words, lower the bucket to the ground, wait a few seconds (keeping the lever in the same position), and THEN it will start to lift the tractor off the ground. As of last fall the pump still brings the pressure up to full spec, though it took a little while. Screens when I cleaned last were very clean. The 3ph lockout valve has been frozen (open, I assume) since I purchased the tractor years ago.


Any thoughts on either question would be greatly appreciated!

 

[kennyd]

1) The best way to "clean out" used cylinders is to remove them from the plow, then disconnect the hoses and cycle them manually. It's very messy but it works well.

2) Sounds like a possible pump problem to me-it should be able to build max pressure almost instantly. There are no bubbles in the hydraulic tank while the tractor is running is there?

 

[couchsachraga]

Thank you for the quick responses!

I've cycled cylinders out in the past..but I know it's not going to get ALL the fluid out. Is getting MOST of the ATF out enough? I don't know much about the negative effects of mixing ATF and Hydraulic fluid...but I do know if some other vehicle fluids with similar consistencies it's not good to mix.


I do not believe there are any air bubbles in the tank, but I'll check when I take a look at it again on Friday. As it's been getting worse over time I've assumed it was likely the pump if it wasn't an air leak...but had been told as long as it builds to max pressure it's still OK.

 

[kennyd]

IMHO the little bit of ATF left in the cylinder will not be enough to contaminate the 5+ gallons of hydraulic fluid in your tractor.

There could be a leak on the RETURN side of the pump causing the pump to cavitate. That could explain some delay.