1811 Hydro Problems...

[mgonitzke]

My 1811 has been giving me heck lately. Ever since I converted it from an 1810 to an 1811 it has been performing strangely. When driven at first it seems normal, until it warms up, when the neutral zone grows and the tractor jerks when transitioning from forward to reverse. It also makes an odd vibrating noise when moving from forward to reverse. I welded up and re-drilled the 5/8 hole in the triangular shaped part of the linkage to remove excessive play and shimmed it with a washer. This didn't fix the problem. I can't seem to get neutral in the right place anymore, and at idle the tractor won't move in either direction, at partial throttle settings when you slowly move the hydro lever forward it does nothing and then all of the sudden jerks and abruptly moves forward. At full throttle the neutral zone is much smaller but it still jerks. I have read the FAQ's and am totally stumped. Anybody got any ideas or had a similar problem?

BTW, I didn't change the hydro pump, it already had a ported pump for some reason. I just changed the implement relief valve spring.

 

[rbedell]

Matt:

Have you changed the HyTran fluid and have a new Hydraulic Oil filter on it...?? Did you change the Charge Relief Spring also..??

 

[digger]

You might do a operation neutral adjust. Can't hurt.
http://cubfaq.com/neutraladjust.html

 

[mgonitzke]

Roland-

Less than 50 hours on hytran and filter change, although the stuff in the cylinder, lines, valve, etc. may have been questionable. I can't remember what the parts tractor the lift parts came out of had in it. I had no idea there was a charge relief spring. I'll swap it with the spring from the parts tractor's pump.

Charlie-

Will do the neutral adjust next time I get a chance.

Thanks guys, I'll keep you updated.

 

[rbedell]

Matt:

I was thinking along the lines that maybe that there is a restricted fluid flow. Only until you build enough pressure, do you get to move. The filter is suppose to catch any junk floating in the system. Maybe that needs changing again. Next, I would look at the Charge Pump. See attached:

 

[mhomrighausen]

Matt G. Let's try this. If the systems operates jerky when starting.... inspect control linkage. If that is okay then inspect the charge check valves. Also, when you changed the implement relief spring by chance you didn't lose any shims did you? Both implement relief and charge relief have tiny shims that are real easy to lose. I know it always says to check the charge pump and I actually know of a gentleman that insists on rebuilding the charge pump everytime that the least bit a 15U acts up. This gentleman worked for years on full size tractors and Cub Cadets. Yes, sometimes the charge pump really does need rebuilding. More often than not--- if properly taken care and with normal usage - they don't. My experience with being on the test stand with the big brothers of the 15U pumps is that if they are making a noise then there could be a wrong part or a part installed improperly or blockage within the system. Here is something else to comtemplate. With charge relief valves or implement relief valves you should not interchange parts with another valve. Check the poppet and the seat in the pump housing for damage and any foreign matter. You may have accidently gotten foreign material introduced into your system that has gotten passed the filter. If it were me then I'd check the basics of what I have done during installation. Also, how did the pump run before you did the transfer. I'm tired so if'n this doesn't make sense let me know and I'll try and get ahold of you this weekend via phone and try and help. I may not have actually worked on the asembly of these little critters ... yet... however from what others with a lot more experience have told me... since I am versed in troubleshooting the big 'uns... apply the same principle to the little 'uns. (Disclaimer... Others may say that I am dang good at troubleshooting. That is their opinion.)

 

[mgonitzke]

It worked just fine before the hydraulic lift was added. When I swapped implement relief springs I also swapped shims. I will do the same for the charge relief valve. I am tempted to change the filter. The hydraulic lift itself seems to work fine, if that helps. The odd noise is only made after the tractor has been used for 45 minutes or so.

 

[rbedell]

Matt G:

Done some research this morning on your issues. I don't know what you did to "convert" your original Hydro, but there is differences in Parts between the 1810 & 1811. See Attached:

As I understand, you have an issue with tractor movement and that the implement lift is OK. I am guessing that the larger Charge Pump needed on the Ported Hydro's might be the problem. See Attached Hydro diagram. The Check Valves help establish the pressure for the Axial Motor (MF output) in both directions.

 

[mgonitzke]

As far as I have been able to tell, my 1810 came with a ported pump from the factory. The charge pump and housing appear identical to the parts tractor's pump. The charge pump is thicker than one on a non-ported hydro. I was told when I originally converted this that the factory probably had a shortage of non-ported pumps when this thing was made, so they just put in a ported one and plugged the ports. The ports had plugs, which I removed and installed the nipples for the lines. I also change the implement relief spring and shims, replacing the originals with ones from the parts tractor that the other parts were removed from. Today I'll change the charge pump relief springs and shims in the same way. Thanks for the additional info, I'll let you know how it goes.

 

[rbedell]

Matt G:

That is possible on the situation with the Hydro Pumps. That same thing happened with the 169 production.

This puts my speculation back to the Filter or the Check Valves.

 

[mhomrighausen]

Matt G. Okay, here goes...your system after awhile is being starved "per se" for oil thus causing the jerky movement when the tractor has been in usage for awhile. Roland is onto something when he said filter or check valves. One of check valves may be sticking in a partially open/closed position. At this point try the valves.

 

[mgonitzke]

UPDATE

I went to swap charge relief valves today and found that the 1810 pump didn't have a charge pump relief spring or the thing that looks like a carb needle. Parts tractor has a spring and carb-needle looking thing. Is it supposed to be this way? I assume this means that the non-ported hydro pumps aren't supposed to have a charge pump relief spring, but I'm not sure.

 

[mhomrighausen]

Matt G. On the top between the two check valves you should find what you are looking for on the non ported pump. That is if'n I'm reading my 123 - 125 hydro pump service section correctly. On a ported pump the implement relief spring is located in that area and the Charge relief is on the side. Both ported and non ported have charge relief springs in them. It is just a matter of location.

Have you considered changing pumps? Maybe pics of both pumps would help us also. And maybe someone would have some good pictures of both the 1810 and 1811 pumps to further help.

 

[mgonitzke]

Marlin H.-

I could change pumps, but I had to do extensive repair and replacement on the one on the parts tractor, and I'm not sure that everthing would work fine on there either. It worked well enough to drive the chassis of the tractor around but I don't know how it would hold up if worked.

I'm referring to the charge relief valve on the side lately here. I changed the implement relief valve spring (the top one, NOT the side one) before. The one that's confusing me is the side one.

Let me see if I'm understanding your post correctly. Are you saying that an non-ported pump has a Charge pump relief spring, but no implement relief spring, and that a ported pump has both? The parts tractor had both an implement relief valve spring and an charge relief valve spring, while my 1810/1811 has only an implement relief spring, but no charge relief spring, just the port and a plug.

I'll attempt to get pictures and perhaps model numbers maybe tomorrow, but more likely Tuesday.

 

[rbedell]

Matt G:

Here is a Diagram for component & valve locations for the Sundstrand Hydros. Please note the locations for items #2 & #4.

 

[mgonitzke]

Ok, I think I see it now...non ported hydro has no valve on the side...that must be why the 1810's pump just has a plugged port on the side. Ported hydro made to resemble a non-ported unit. I'll put the charge pump relief valve parts where they belong and see what happens.

 

[mhomrighausen]

Roland B. Thank You for the pics. They explain fantastically.

Matt G. Roland's pics should help you. I asked a couple of coworkers about the jerky movement when warm. Contamination or a sticky valve or a combination of both. You would be amazed at how a human hair will actually freeze up a charge pump on the test stand. It doesn't happen very often however it has. So if a hair can do that then a piece of what ever floating around in a hydraulic system (contamination) could cause a sticky valve. Or the valve may be faulty.

Now for something somewhat off topic. When my Mom purchased a new 1971 966 the hydraulic system never quite worked right. It would either work fine, stick up in position, seep and lower when the tractor was not running or even when running. After several under warranty trips to the local IH dealer the problem was never fixed. Their "qualified" Bondafide top notch mechanics were perplexed. I watched them work on the tractor. Everytime they would just put some weight on the tractor and move the levers. Now here is where the DUH factor sets in. That is ALL they did. The following spring and now out of warranty the hydraulic system literally dropped the disc one morning while the tractor was running. If my right foot had been a few inches further then I would have lost it at that moment. We took the tractor immediately to Dean Bassett by Davenport. Three days later and over $565.00 later they discovered that from the factory the valve under the seat was faulty. None were available from the factory so they rebuilt it even though it was supposed to be nonrebuildable. The ball wasn't seating properly everytime. Their mechanics said that problem should've been caught under warranty. We remembered that when a year later we purchased a 990 cut/ditioner... from Dean Bassett instead of the local guy.

Now I guess what I am trying to say is this. You have a system at least How old? If the tractors were sitting for a couple of years there is the possibility of one of the valves sticking.

Thank you for your patience and my rambling. Hope this helps.

 

[mgonitzke]

Thanks for the info. Here's the current plan:

1. Add the charge pump relief valve in the correct location

If that doesn't help then I'll:

2. Remove and inspect valves (If they are sticking, how do you get them to stop?)

3. Change the filter.

 

[rbedell]

Matt G:

Here is a picture of a Automatic Check/Relief Valve, cut open. The only maintenance is, remove the valve from the Hydro. Note, the plunger, springs and ball. Those components have to be clean and free to travel up and down the internal bore of the valve body. You could clean these parts with products like: brake cleaner, lacquer thinner, acetone, etc. Once cleaned up, blow out assembly real good with compressed air. By blowing air in the end, you can see the plunger move up & down. Once cleaned and dried, then you could immerse the valve in Hytran and re-install. You should be good to go at this point.

 

[mhomrighausen]

Matt G. If a spring is put in the wrong location this tends to affect performance immediately. (If I recall correctly you said the problem happens after the tractor has been operated around forty + minutes and the oil has warmed up.) This being due to the tension on the spring may be different from the required spring. So, therefore either more oil flow or less oil flows through the system. This is why I tend to think the springs are of importance only aren't the cause of the immediate jerky movement.
The jerky movement as I stated earlier makes me think of a system that isn't getting full flow when the entire system is calling for that amount. Or even if it is calling for partial (say half flow) and the system has a restriction somewhere.
I've seen on a test stand where after a pump was accidently "blown up" that a piece of whatever broke got stuck in a valve and that valve either stuck open or would have such restricted flow that we had to have the valve replaced. Yes, I've accidently "broken a few" pumps by not having a hose hooked up all the way. You sure feel like a dumb***

after doing that. I've since learned to double check. Only a couple people hear that happen. When the charge pump siezes up.... Everybody hears that.