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IH 815 hydraulics

9562 Views 7 Replies 4 Participants Last post by  Ohio Farmer
Okay I have a 1975 IH 815 diesel and am having issues with the rate of the header drop. When it has a head hooked up to it the feeder house will drop a little to fast when I lower it. I've adjusted a screw on one of the pumps that the manual says to, but its adjusted almost all the way in but its not making a difference. Any ideas what it could be? Thanks for any help.
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Not sure which screw you were adjusting? On the slightly more modern combines, I believe you should be choking the return flow back by the header lift valve. Normally, these headers gravity feed down and return it to the same valve block as it came from. I am not sure what an adjustment screw at the pump would do for you!
I had an 815 several years ago and I can't remember exactly where it was at ,but there is definitely a drop rate adjuster that takes 2 , 1/2 inch wrenches if I remember right .It should be on the control valve that the header drop hand lever is hooked to under the cab. Mine also used to drop it faster if I was goofing around the barn lot at a slow engine speed versus having it revved up to normal operating speed. Is yours a cable float control? It seems if I remember right there were some changes that had to be made back at the control valve(where the cable hooks up) on the hydraulic lines when you went to corn head(manual drop) versus platform head(cable control) . Do you have a manual. Mine went with the combine when I sold it but I do remember it showing that adjustment screw along with drop rate setting directions !

Also...your cylinders should have some springs on them that need to be set tight enough to soften the fall rate. Wish I could remember what all the settings were.
I had a 915 at one time. Sold the combine and kept the manual. If its the same as a 815 then the valve is on the left side behind the operators platform. Adjust the screw clockwise to slow the drop. Mine didn't have springs on the cylinders. I think that was if you had the automatic height control. As Ohio Farmer said, you had to block off the fast drop valve if you were going to run a cornhead. This is information that I found in my manual, which may or may not pertain to a 815.
Thanks, this is all good information! It'll give me a few things to try hopefully they work. And yes I have the cable control auto-header height however I have a newer 820 20' platform that has electric auto-header height so I'm just going to have to run beans manually which is one reason I really want to slow down the rate the header drops. It also has the springs on the cylinders which I noticed had no tension on them so if I adjust those maybe it will help as well. Now to block off the fast drop valve is where you turn in the screw isn't it? Because I've got it turned in pretty much all the way but no difference in letting it down. It picks up nice and easy but drops fast. Thanks again guys for the input I appreciate it!
That control valve that the cable would normally hook too prolly can't just be left with nothing hooked to it unless you set those hydraulic lines to a corn setting ! That's prolly whats going on..

I cut beans with a 810 13 foot head manually when I first got that combine and it was also the first time I had ever cut what a learning experience !! I would be hung over top of that steering wheel a nervous wreck and when I would get to the end of a row I would light a ...turn around and do it again. I have since quit smoking and the next year I had a cable controlled 820 header.! Good Luck Bubba
Okay I got it solved! Thanks a lot for the help! It lets down very nicely now. The only slight thing is that when you push the lift/lower lever forward (Down) its almost like there's two notches and slightly forward it wants to raise so you have to push it far enough for lower and I thought that was sort of strange. However, its not real severe and it'll be easy enough to work with now but I wondered if any of you guys knew if it was supposed to do that or how could I make it not do that. If not, it can still be easily operated as it is now.
Probably something in that valve...I can remember mine would try to let down when trying to raise unless you swiftly moved the valve all the way to raise. If you tried to move the handle partially it would drop it !
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