cleat 6,868 #1 Posted February 18 (edited) This procedure is for the valves installed in 300, 400, and 500 series. May be others as well. This valve is from a 520HC Here is the valve ready for new O rings. You know the O rings are worn because it had a leak and the control rod is very easy to turn. Getting ready to remove the screw retaining the rod. Screw in end of rod removed. Rod pulled out. It came out really easy since the O rings offer no resistance because they are worn out. O rings removed using a brass pick to prevent damage to the rod. You can use any tool, just be careful not to scratch the shaft. New #111 Nitrile O rings ready to install (Viton would be better but Nitrile is what I have on hand). I also used 111 O ring lubricant which is basically silicone grease. O rings installed. O rings lubed with the 111 O ring lubricant. Rod inserted into valve body. This will take a bit of a push with the new O rings Screw installed into end of control rod. Valve is now complete and should no longer leak. I did not touch the pressure relief cap as I have never had one leak from there and don't want to mess with the relief setting. Edited February 18 by cleat 2 11 Share this post Link to post Share on other sites
pfrederi 18,201 #2 Posted February 18 (edited) So much easier than the seals on the older control valves used on Chargers electros etc. Teen tiny snap ring to remove instead of the simple screw... and not o rings but a cup like seals that are hard to get put back into the housing with out damaging them. Edited February 18 by pfrederi 2 Share this post Link to post Share on other sites
ri702bill 8,769 #3 Posted February 18 (edited) Easier to reinstall the control rod assembly if you push and slowly rotate the shaft. Excellent writeup - perhaps it should belong in the Instructional Section ?? Edited February 19 by ri702bill 2 Share this post Link to post Share on other sites
JCM 9,931 #4 Posted February 18 18 minutes ago, ri702bill said: Excellent writeup - perhaps it should belong in the Instructional Section ?? 1 Share this post Link to post Share on other sites
kpinnc 13,147 #5 Posted February 18 42 minutes ago, ri702bill said: Excellent writeup - perhaps it should belong in the Instructional Section ?? Though it should include the nightmare of getting the valve out and reinstalled... Joking of course. Excellent write up @cleat!!! 3 1 Share this post Link to post Share on other sites
lynnmor 7,495 #6 Posted February 18 20 minutes ago, kpinnc said: Though it should include the nightmare of getting the valve out and reinstalled... Joking of course. Excellent write up @cleat!!! That ain't no joke, without instruction it can be difficult till one figures out the answer to the puzzle. 2 2 Share this post Link to post Share on other sites
cleat 6,868 #7 Posted February 18 1 hour ago, kpinnc said: Though it should include the nightmare of getting the valve out and reinstalled... Joking of course. Excellent write up @cleat!!! I will be replacing the O rings in my 520HC with Viton ones soon. The O rings are on order but should be here soon. The Nitrile ones have swollen making the valve hard to move. I am blaming the synthetic oil I put in this tractor for the swelling since it has not happened to any of my other tractors with regular oil. I will document that as I do it. 1 1 Share this post Link to post Share on other sites
ri702bill 8,769 #8 Posted February 18 41 minutes ago, cleat said: I am blaming the synthetic oil I put in this tractor for the swelling since it has not happened to any of my other tractors with regular oil. I am a firm believer in checking the compatability prior to switching to another style fluid - home, cars, tractors. 1 Share this post Link to post Share on other sites
Brockport Bill 1,786 #9 Posted February 18 3 hours ago, kpinnc said: Though it should include the nightmare of getting the valve out and reinstalled... Joking of course. Excellent write up @cleat!!! did the a remove and reinstall of master valve twice in past 2 yrs -- first on C175 Series 2, then on C175 Series 1 a few weeks ago - - absolute nightmare -- i still have the wounds on back of my hands to remove and put back in -- did the O ring replacement as well as new hoses -- hopefully never again !!!!UGH !!! 2 1 Share this post Link to post Share on other sites
pfrederi 18,201 #10 Posted February 18 (edited) Okay so Charger Electro control valves were harder to rebuild but getting them off lots easier Edited February 18 by pfrederi 3 Share this post Link to post Share on other sites
ebinmaine 69,812 #11 Posted February 19 @cleat Excellent write up as usual. I also vote for this being added to the Instructional Section. @Sparky The ease in repair and maintenance is one of the reasons we have the older Herd here! Share this post Link to post Share on other sites
WheelHorseVH 107 #12 Posted February 19 Ok I need to ask here because @kpinnc @lynnmor @Brockport Bill all mentioned the pain of doing it....does anyone have instructions, pictures, or anything on how to remove the valve from a 520H? I need to do this in order to add another valve in series and I just don't know where to begin. Are we talking taking apart the entire hoodstand? I have no clue how I will get the forward facing P and T metal lines disconnected. Any help is very much appreciated. Thank you. 1 Share this post Link to post Share on other sites
Brockport Bill 1,786 #13 Posted February 19 2 hours ago, WheelHorseVH said: Ok I need to ask here because @kpinnc @lynnmor @Brockport Bill all mentioned the pain of doing it....does anyone have instructions, pictures, or anything on how to remove the valve from a 520H? I need to do this in order to add another valve in series and I just don't know where to begin. Are we talking taking apart the entire hoodstand? I have no clue how I will get the forward facing P and T metal lines disconnected. Any help is very much appreciated. Thank you. sorry i do not have a 520 in front of me to make the comparison to a c175 of the early 80s era generation of WH models -- obviously the hoodstand design is different but hard for me to make comparison to the 520 model not having 520 visually side by side - i did just look at a 314h with that valve unit -- but the dash hoodstand design for 314 is also different than c175 or 520 ---- here was the challenge for me - - the access from engine side is limited - and taking off the front plate facing the engine below the battery tray is not fun -- but it does give me access - - then of course there is removing the dash from the seat side -- i removed both seat and engine sides so i could work and manipulate valve and hoses from both sides -- the challenge for me was removing and then reinstalling the bolts that "hang" secure the valve unit from its bracket and the battery tray area -- what makes it all more difficult is the hoses are very awkward to "thread" in and out of the side wall hole - - they are stiff and not easily manipulated - worse is trying to position the hoses while holding the valve to seat the bolts and then tighten back in place - one decision to make is do you want to connect the hoses to the valve unit before or after removing and or re-attaching the valve unit -- Frankly both options are difficult. Others who have done this may have a few tips or secrets -- one i would suggest is for anyone planning this project is to do at same time as other projects ( including hose replacement ) that may involve that part of the tractor ( eg: steering repair etc ) so it's easier to justify maybe removing/disaseemble of hoodstand or other parts so you are not doing the valve unit now and some other repair soon thereafter - - try to anticiapte other maintenance and do premptively while doing valve/hoses project - - good luck - oh yeah - the bigger your hands the more challenging! Have fun !!!! Bill more photos below Share this post Link to post Share on other sites
WheelHorseVH 107 #14 Posted Thursday at 03:22 AM Thank you for that, its very good info. Hopefully someone with a 520 can chime in as well. I was really hoping that I would not have to pull the entire hoodstand apart. I am utterly ashamed to admit that I am one of the few wierdos on this site who only has one Horse :). And I fear that tearing the hoodstand apart in addition to the additional hydraulic circuit project I am trying to do is going to turn this into months of downtime. Rough order of magnitude, complete removal and reassembly of the hoodstand…no hydraulic work…16 hours? Assume an average mechanic. Share this post Link to post Share on other sites
lynnmor 7,495 #15 Posted Thursday at 10:30 PM 19 hours ago, WheelHorseVH said: Thank you for that, its very good info. Hopefully someone with a 520 can chime in as well. I was really hoping that I would not have to pull the entire hoodstand apart. I am utterly ashamed to admit that I am one of the few wierdos on this site who only has one Horse :). And I fear that tearing the hoodstand apart in addition to the additional hydraulic circuit project I am trying to do is going to turn this into months of downtime. Rough order of magnitude, complete removal and reassembly of the hoodstand…no hydraulic work…16 hours? Assume an average mechanic. Pull the battery and its plastic tray. There are holes where you can use a 7/16” socket to remove the bolts holding the control, an end wrench will be needed to hold the bottom of the bolts. Of course you need to pull both of the console plates which have four Phillips in each. Do that much and come back here if you have problems. 2 Share this post Link to post Share on other sites
