318 Lost Hydro Pressure..

monster318 · Dec 3, 2015

Hey guys...

Towards the end of summer, I took my 318 up to a good friends house to push some dirt around for them with the blade, had it loaded down with the blade, rear bracket with 6 suitcase weights on it, plus 135lbs in each wheel. As I am pushing this dirt around, I am using the tractor probably the hardest I have ever used MY 318, (my cousin as 7 318s which over the years I have beat on way harder then how I was using mine). As I am using it, I notice it seemed to be losing power, not really engine wise, more in the hydraulic system. I was having to push the lever further and further up to make it move and to me it just felt like the power wasnt there that it should or used to have. Then I notice that as I am traveling along not pushing anything or even have the blade down, if I pull on either lever to angle or lift the blade, the tractor slows down instantly and starts crawling along, if I release the lever, the tractor takes back off again. I got off the tractor and checked the rear sight lens and it has fluid in it in the glass part where it is supposed to be...

That's as far as I have gotten for now, I brought it home and drove it to the back of the garage and that's where it has sat since. With winter coming and I am responsible for doing about a half a dozen elderly peoples driveway for snow removal, I decided it was this weekend that I will action and figure out what is going on.

I have a Service Manual that I am currently thumbing through, I was wondering if you guys had any input on where to start??

Fluid was changed by previous owner right when I bought it, about 150-200hrs ago.. Fluid Type unknown...and doesn't seem to be leaking anywhere visible.

beenthere · Dec 3, 2015

A place to start... first I'd fire it up and see if it runs ok when the oil is cold.

Regardless, I'd change the fluid to Deere oil. Non-Deere specials may say they meet Deere's specs, but it is very easy to say whatever because no one is checking to see that they speaketh the truth.
Oil filter on this one? if so make that change too.

Amvcane · Dec 4, 2015

While driving with the hst lever in a fixed position, does the tractor slow down when encountering a hill and speed up when reaching the apex or going down the other side?
If so, this may be the classic symptom of worn hst linkage or tired hydraulic dampener. There are, I think 4 different iterations of the hst linkage depending on tractor serial number.
I am very interested in your outcome please keep us posted. You may also want to try Weekend Freedom Machines forum.

monster318 · Dec 6, 2015

Well sorry guys, outcome is going to be delayed a bit, we had some surprise visitors this weekend, my fiance's old roomates from college came and stayed at the house this weekend so I didnt get a chance to go out and tinker in the garage. This tractor does have the filter on the transmission and that will be the first thing I am going to do is change the fluid and filter.

I just signed up for weekend freedom machines like you suggested, there is one forum I signed up for 2 years ago (I think it was mytractorforum) and they still wont let me post, I emailed them about it and no response...thats when I signed up at tractorbynet.

Thanks

Kyle_in_Tex · Dec 6, 2015

I have had hydraulics fail due to one of the levers not quite closing the valve it was attached to. This causes the oil to go through a small crack and get real hot in the process. Eventually, the oil being real hot and thin, is what causes the other systems to fail. This has happened on my ehydro 4310 and on our shuttle shift 5420.

Leejohn · Dec 6, 2015

While changing oil and filter find out if there is a screen filter in the sump, if so clean it.

monster318 · Dec 6, 2015

I have ordered hydraulic hoses from this guy before, I think I am going to order this test gauge to help diagnose what is going on.

Hydraulic Pressure Test Kit

Yeah I could prob buy all the parts and make the tool, but its just easier to buy it right now

monster318 · Apr 10, 2016

Ok so its been quite a long delay but now that I am between seasons and my work schedule slowed down a bit I finally got into looking more in depth of what was happening. First thing I did was change the fluid and filter. My nearest John deere dealer is about 30 minutes away, So I ventured down there and got two gallons of fluid and a new filter. It wasn't until I got home that I realized I grabbed "Low Viscosity Hygard" So i looked up the specs on that and came to the conclusion that it should be alright for my use as long as I don't go out and mow the grass on the hottest day of the summer.

So I changed fluid and filter and drove it around, the transmission doesn't seem to make as much noise as it used to, but still just didn't seem to have the power it used it. So today I took the seat deck cover off and the side of the dash tower. Pretty sure I found the issue, The rod that goes from the turnbuckle to the hydro lever at the dash, the hole in that the bolt goes through is worn very oblong allowing about 1-2 inches of movement in the whole linkage without moving the Hydro lever at all.

So by having this play in the linkage, its allowing me to have the hydro lever almost 1/2 way up the dash before it even starts pulling on the linkage attached to the transmission. Therefore giving me the feeling I am only at half power, cause in reality, I am!