lynnmor 7,306 #1 Posted January 20, 2022 I have been keeping two 520H tractors in an enclosed trailer. The temperature has taken some big swings and I believe the trailer exaggerates that some more. Last week I cleaned up a sizable oil spill, so I thought it might be done peeing, but no, it did it again. This time I pulled the transmission dipstick first thing and the oil ran out the top of the tube. This is getting old. I guess that the oil from the pump is draining down into the differential area and overfills it. My guess is that the temperature changes causes a pumping action as air trapped inside expands and contracts. Yes, the vent in the dipstick loop is open. The other tractor hasn’t been a problem. 1 Share this post Link to post Share on other sites
Ed Kennell 38,171 #2 Posted January 20, 2022 I can help. 5 Share this post Link to post Share on other sites
WHX?? 48,815 #3 Posted January 20, 2022 Guessing with your experience with 520's it's not overfilled so rule that out. Could it be that the charge pump is draining back to the sump overfilling it? When to start it does it take awhile for the charge pump to build up? My 520 tractors most notably when the charge pump gets oil and starts to whine. In really cold weather only tho. What oil are you running? 1 Share this post Link to post Share on other sites
lynnmor 7,306 #4 Posted January 20, 2022 18 minutes ago, WHX?? said: Guessing with your experience with 520's it's not overfilled so rule that out. Could it be that the charge pump is draining back to the sump overfilling it? When to start it does it take awhile for the charge pump to build up? My 520 tractors most notably when the charge pump gets oil and starts to whine. In really cold weather only tho. What oil are you running? It wasn’t overfilled, but I do run the oil near the top line. The fact that it lost some oil made me think that it would be OK. Yes, the oil must be coming down from the pump, I don’t know if there is a good fix for that. I use 10W-30 semi- synthetic Castrol high mileage oil and performance is just fine. I wonder if those NAPA filters might be the problem? 1 Share this post Link to post Share on other sites
roadapples 6,983 #5 Posted January 20, 2022 All I use is NAPA filters... 4 Share this post Link to post Share on other sites
kpinnc 12,028 #6 Posted January 20, 2022 One of my Eatons burps every time I push it around. The case needs a vent... Nevermind the slow oil fill issue. 3 Share this post Link to post Share on other sites
WHX?? 48,815 #7 Posted January 20, 2022 12 hours ago, lynnmor said: oil must be coming down from the pump, Leaking seal from either the input shaft or the motion arm on top? Loose fitting on the top or bottom of the charge pump? Those are about the only places the pump could leak. I use the NAPA 1410 on all three my 520s with no problems. 1 Share this post Link to post Share on other sites
lynnmor 7,306 #8 Posted January 20, 2022 1 hour ago, WHX?? said: Leaking seal from either the input shaft or the motion arm on top? Loose fitting on the top or bottom of the charge pump? Those are about the only places the pump could leak. I use the NAPA 1410 on all three my 520s with no problems. The oil is coming out the top of the dipstick, my thought is that oil in the pump is draining internally and goes down to the sump (differential) area. There are no leaks elsewhere. Also, oil from the filter may be doing the same thing. I have four of this model and the issue is random, the only common denominator is temperature changes. Do you keep them filled to near the top line? Do they get exposed to temperatures that are from the teens to very warm? Share this post Link to post Share on other sites
Handy Don 12,223 #9 Posted January 20, 2022 (edited) 1 hour ago, lynnmor said: The oil is coming out the top of the dipstick I'm wondering if the bottom of the filler tube is submerged in the oil which would prevent expansion being vented as air through the dipstick vent and instead forcing oil upward and out. The way the plumbing and internal valves of the hydro are set up, it'd be tricky for the pump oil to flow back into the transaxle, I think. Also, aren't all of those components lower than the lip of the filler tube? My suspect would be any hydraulic components higher up--a control valve or a hydro cylinder in the loop, for example--since their path back to the transaxles has no check valves and is direct through the hydro filter. Also, for oil to flow downward there would have to be air flowing upward to the same spaces or air entering from above somewhere. You don't have any leaks so how is the air entering the system without oil exiting? (Air in the system does, of course, get purged while running via the transaxle "reservoir" and dipstick vent.) Edited January 20, 2022 by Handy Don Share this post Link to post Share on other sites
Goldnboy 920 #10 Posted January 20, 2022 There is a hex drain plug on the bottom front. Mine developed a tiny pin hole leak in the plug. Cost to fix $6 ,time to fix about 6hrs complete tear down to get to it. Share this post Link to post Share on other sites
WHX?? 48,815 #11 Posted January 20, 2022 45 minutes ago, Handy Don said: bottom of the filler tube is submerged in the oil Nope bottom of tube is dang near flush with the top of the gear box and if I remember right the top line of the dipstick is a good couple of inches below that. 2 hours ago, lynnmor said: Do you keep them filled to near the top line? Do they get exposed to temperatures that are from the teens to very warm? My lift cylinders leak like no tomorrow so sealcoating the drive with Mobile 1 and always below the fill line. One of these days I'll get around to installing them seal kits Lynn. My 1100s are all cold weather workers except for the C-195 and never had this issue. Share this post Link to post Share on other sites
