Hydro 100 steering problems

Hydro10037 · Jul 30, 2023

Hey guys I have a 1974 hydro 100 I bought back in the winter. The steering is stiff and will barely turn under 1500-1800 rpm s. Steers good once moving and the rpm s are up. So far my mechanic has replaced the mcv pump twice, the MCV valve, checked the flow divider, and I even ordered another used MCV body, and changed it but still didn t help. Only getting 250 psi at idle going to the steering pump at idle. He called herrs hydro and they instructed him to check the main hydro pump. They said anything over 300 psi was good. It tested at 450 psi. The main hydro is also very responsive and strong when running it so I don t think it s the main hydro. Right now we are grasping for any way to fix it. Also going to attach a picture from another post from a 1066 hydro about the routing of the hoses and a picture of mine. Is there any way my hard lines could have been Replaced and that is causing the problem?? Completely stumped as you can tell.

caterpillar guy · Jul 31, 2023

When was the last time the front end was greased and is it worn out in the bushings and bearings? Those will make it steer hard. Then when you changed MCV's did you check the springs and valves to make sure they were good. Also did you use new o-rings between the MCV and pump and the transmission casting where it bolts on or the old ones. The old ones squash take a set or just flat will leak allowing for low pressure. IF all this was done you now are down to a flowrater to find the problem of either low pressure or low volume.

Hydro10037 · Jul 31, 2023

The front end has been greased and its tight so I dont think that is it. All the springs and valves in the MCV has either been changed or made sure they are free and working. I will have to ask my mechanic about the o rings between the transmission housing and the pump. Thank you for trying to help! Another question, on a gear drive say 1066 they use the 9 gallon MCV pump.Im the left side of the transmission. That is the pump that was installed in my hydro 100 on the right side where the MCV valve body is. I got to searching last night online, and cant find where it says the 9 gpm MCV pump fits a hydro 100. In the parts diagram of a hydro 100 it shows part 44 the main hitch pump 12gpm on the right side next to the MCV valve body. Behind it is a gasket and then a piggy back draft control pump part 42. My question is does a hydro 100 even use a 9 gpm MCV pump? When I bought the tractor it had a 9gpm MCV pump in it and the steering was stiff. Did the previous owner install the wrong pump and then we have done the same? Just racking my brain for any answers!

Paul swpa · Jul 31, 2023

Simple thing you may have done but didn't mention, did you change or check any filters in the system? Not familiar with the 100 hydro, but other IH tractors have a filter on side of case (usually right side, just in front of wheel, under cover held on with thumb screws). A poor filter or any problem there will affect steering first. Also if air in system usually need to turn steering wheels full lock and hold a bit then go other way full lock and hold a bit, to bleed air out. Some things that get overlooked. Had a filter cover that I didn't get on right one time (pinched o-ring) and thoroughly messed up the steering.

Other than that I would suspect the wrong pump was put on at some time, as you say the book calls for a 12gpm and you have a 9gpm on there. Plus you say it gets better with higher rpm (more gpm flow). Paul

Hydro 100 steering problems

Hydro10037

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caterpillar guy

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Hydro10037

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Paul swpa

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