Hi guys,
Two of my 3 newly-installed rear remote valves are both very "tight" (takes a lot of pressure on the levers) and seem to be "sticky" when they do move. Sticky enough that they don't return to center very well. Kinda have to be manually set there. The third (farthest outboard) is fine. Silky smooth. The valves are Kubota OEM with float, no manufacturer name is obvious on them. They sat in my climate-controlled basement for the better part of 2 years after I unwrapped them from the shipping wraps. They were SATURATED with a heavy oil inside and out from Kubota. I wiped off the outsides, but assumed that the insides were still plenty juicy. At least enough to prevent any rusting. All 3 have been assembled all this time together with the feed/return lines. Basement stays at 65deg +- about 5deg and 50% humidity +- about 10%.
Now, I fear that just from air migrating through the lines/valves, that the two inboard valve spools or bores have some rust that is causing what I'm feeling. After I got them plumbed, I flushed about a pint of hydraulic fluid through each "side". It was dark, but I didn't see any particulate matter. It also didn't really change their behavior.
So finally my question(s); have I likely ruined these 2 valves? Would it be advisable to connect a "U-hose" between the two rear connections for each of these valves and cycle them back and forth a few times in an effort to further flush and clean and polish the spools/bores? If I use a u-hose then any rust/debris will get routed back to the hydraulic sump, right? Tractor is an HST, so I'm worried about intentionally flushing ANYTHING, even to the sump. If I just connect my new cylinders and use them, any debris will be deposited inside the new cylinders and possibly contribute to early seal failure, right?
Two of my 3 newly-installed rear remote valves are both very "tight" (takes a lot of pressure on the levers) and seem to be "sticky" when they do move. Sticky enough that they don't return to center very well. Kinda have to be manually set there. The third (farthest outboard) is fine. Silky smooth. The valves are Kubota OEM with float, no manufacturer name is obvious on them. They sat in my climate-controlled basement for the better part of 2 years after I unwrapped them from the shipping wraps. They were SATURATED with a heavy oil inside and out from Kubota. I wiped off the outsides, but assumed that the insides were still plenty juicy. At least enough to prevent any rusting. All 3 have been assembled all this time together with the feed/return lines. Basement stays at 65deg +- about 5deg and 50% humidity +- about 10%.
Now, I fear that just from air migrating through the lines/valves, that the two inboard valve spools or bores have some rust that is causing what I'm feeling. After I got them plumbed, I flushed about a pint of hydraulic fluid through each "side". It was dark, but I didn't see any particulate matter. It also didn't really change their behavior.
So finally my question(s); have I likely ruined these 2 valves? Would it be advisable to connect a "U-hose" between the two rear connections for each of these valves and cycle them back and forth a few times in an effort to further flush and clean and polish the spools/bores? If I use a u-hose then any rust/debris will get routed back to the hydraulic sump, right? Tractor is an HST, so I'm worried about intentionally flushing ANYTHING, even to the sump. If I just connect my new cylinders and use them, any debris will be deposited inside the new cylinders and possibly contribute to early seal failure, right?