Matthewand horses 2 #1 Posted March 9, 2023 Where do I fill the hydro transmission when I drain all of it out, first time I have messed with hydro models. 1974 C120 2 Share this post Link to post Share on other sites
Achto 27,743 #2 Posted March 9, 2023 45 minutes ago, Matthewand horses said: Where do I fill the hydro transmission when I drain all of it out If there is a dip stick under the seat you can fill though there. Share this post Link to post Share on other sites
daveoman1966 3,758 #3 Posted March 9, 2023 (edited) To prevent over-spill and a mess, get a small funnel and a 12-14" drinking straw... then. CAUTION... do NOT overfill. After you first fill it, drive around for a few minutes and work the hydraulics. After that, go back and 'top off' the trans fluid to mark on the dipstick. If you over-fill the unit, it will foam up at some point with potential damage to internals. Edited March 9, 2023 by daveoman1966 3 2 Share this post Link to post Share on other sites
rjg854 11,472 #5 Posted March 10, 2023 @Matthewand horses I use a large cable staple on the outside of the funnel tube that goes inside the filling neck. Keeps a spot for the air to get out. The staple is to big to fit down the filling neck, so I just use one leg of the cable staple. Works for me. That's my 2 cents. 1 Share this post Link to post Share on other sites
Sailman 1,294 #6 Posted March 10, 2023 (edited) 19 hours ago, Matthewand horses said: Where do I fill the hydro transmission when I drain all of it out, first time I have messed with hydro models. 1974 C120 Definitely take the advice of the folks here allowing a path for the air to escape as you fill. If not it will "burp" and you will have oil spattered all over! Funny thing is, I have had a C-120 that filled just fine and a second one that was a PIA...burping all over....before I heard about the suggestions here. One other thing recommended is to jack the front of the tractor up when draining the oil out. It helps clear a small hump in the transmission and get most of the old oil out. Also, be sure to replace the filter with NAPA 1410 or WIX 51410 filters as they are designed for hydro's and are not an oil filter. Edited March 10, 2023 by Sailman 1 Share this post Link to post Share on other sites