4500 Mahindra Steering

[dhillis84]

FIL has a Mahindra 4500 that we have been having steering problems with for the last year. I finally decided to get it fixed myself so we have it to use out at the farm. A year ago the hydrostatic pump that is under the steering column busted a leak. We took the pump to a dealer and had the pump rebuilt. We reinstalled the pump and have been having problems since. A couple of weeks ago we replaced the hydraulic pump that is on the engine block. The wheels turn much better but the steering wheel never hits a stop. The wheels will turn and stop, but the steering wheel continues to turn freely. This occurs in either direction.

I read that to test the pump you can detach both of the lines that connect to the cylinder and plug them. If the pump builds pressure and stops then the cynlider has an internal leak, and if it doesn't then the hydrostatic pump is bad? Does that sound right? Any tips or suggestions before hauling it to the dealer.

 

[Jabonee]

I would perform a leak by test on the cylinder.You only have to disconnect one hose from the cylinder.:thumbsup:

 

[dhillis84]

Can you elaborate on the test. First hydraulics I've messed with. I'll look online also.

 

[oldpilgrim]

The steering wheel will never hit a stop as it has no direct connection to the front axle. It doesn't turn a gear box like conventional steering, but just directs hydo fluid to a cylinder.

 

[Jabonee]

Can you elaborate on the test. First hydraulics I've messed with. I'll look online also.

Turn the steering wheel till you hit the stop on front axle. determine which side hyd hose moved the wheel in that direction on the cylinder.Probably ram retracted. Remove the opposite side hose and cap it. Continue to turn the steering wheel in the same direction and observe the open port on the steering cylinder. There should be little to no oil coming out. Careful it could be messy if the cylinder is bad.:thumbsup:

 

[dhillis84]

The steering wheel will never hit a stop as it has no direct connection to the front axle. It doesn't turn a gear box like conventional steering, but just directs hydo fluid to a cylinder.

I'm 95% sure it use to have a stop?? After thinking about it, maybe it wasn't a true stop, but shouldn't there be enough back pressure that the wheel gets hard to turn?

 

[dhillis84]

Turn the steering wheel till you hit the stop on front axle. determine which side hyd hose moved the wheel in that direction on the cylinder.Probably ram retracted. Remove the opposite side hose and cap it. Continue to turn the steering wheel in the same direction and observe the open port on the steering cylinder. There should be little to no oil coming out. Careful it could be messy if the cylinder is bad.:thumbsup:

I'll try this. Probably won't be until some time next week before I can get back to it.

 

[Jabonee]

I'm 95% sure it use to have a stop?? After thinking about it, maybe it wasn't a true stop, but shouldn't there be enough back pressure that the wheel gets hard to turn?

Yes.Steering wheel should get hard to turn when at full left or right.:thumbsup:

 

[dhillis84]

Yes.Steering wheel should get hard to turn when at full left or right.:thumbsup:

Thanks for the help so far. I'll try to test the cylinder at some point over the next week. I'll reply back.

 

[oldpilgrim]

After thinking about it, maybe it wasn't a true stop, but shouldn't there be enough back pressure that the wheel gets hard to turn?

yes, but you can still turn it. there is a stop on the axle but there is nothing in the steering column.

 

[dhillis84]

yes, but you can still turn it. there is a stop on the axle but there is nothing in the steering column.

I should have clarified. The steering wheel doesn't get hard to turn at all. Just keeps spinning at the same resistance, which is hardly any. Need to find out if it is the cylinder or the hydrostatic pump under the steering column.

 

[Jabonee]

yes, but you can still turn it. there is a stop on the axle but there is nothing in the steering column.

Correct. Once the steering cylinder strokes out oil is forced over the steering relief valve.Wheel will still turn but be hard.:thumbsup:

 

[dhillis84]

Turn the steering wheel till you hit the stop on front axle. determine which side hyd hose moved the wheel in that direction on the cylinder.Probably ram retracted. Remove the opposite side hose and cap it. Continue to turn the steering wheel in the same direction and observe the open port on the steering cylinder. There should be little to no oil coming out. Careful it could be messy if the cylinder is bad.:thumbsup:

DO you happen to know what size threads I need to cap the hose?

 

[Jabonee]

DO you happen to know what size threads I need to cap the hose?

No not off hand. Best guess is JIC flare #6. You can test with out the cap. It just keeps the mess to a minimum.:thumbsup:

 

[dhillis84]

No not off hand. Best guess is JIC flare #6. You can test with out the cap. It just keeps the mess to a minimum.:thumbsup:

I also remember reading somewhere else that to test the pump I could plug both hoses and see if pump built pressure when turned. Does that seem accurate?

 

[Jabonee]

I also remember reading somewhere else that to test the pump I could plug both hoses and see if pump built pressure when turned. Does that seem accurate?

Yes. Idealy though you should install a pressure gauge. That would tell you if the relief valve and supply pump are working. If I was looking at your tractors service manual correctly,it has a dedicated supply pump. The relief valve is in the steering valve. Most times I see the steering cylinder fail but it could be any of the three components.:thumbsup:

 

[dhillis84]

Yes. Idealy though you should install a pressure gauge. That would tell you if the relief valve and supply pump are working. If I was looking at your tractors service manual correctly,it has a dedicated supply pump. The relief valve is in the steering valve. Most times I see the steering cylinder fail but it could be any of the three components.:thumbsup:

Finally got around to testing the cylinder yesterday. Took off the wrong hose the first time. Oil everywhere. Put it back on, took off the other and again oil everywhere. Guess the cylinder is bad. Ordered the seal kit today. Hopefully by end of next week i'll have it right by next week.

Also, where did you find the service manual?

 

[Jabonee]

Finally got around to testing the cylinder yesterday. Took off the wrong hose the first time. Oil everywhere. Put it back on, took off the other and again oil everywhere. Guess the cylinder is bad. Ordered the seal kit today. Hopefully by end of next week i'll have it right by next week.

Also, where did you find the service manual?

I have online dealer access for owner/service manuals.To clarify test, you had oil coming out the open port on the cylinder when you turned the wheel and the cylinder was stroked out?

 

[dhillis84]

I have online dealer access for owner/service manuals.To clarify test, you had oil coming out the open port on the cylinder when you turned the wheel and the cylinder was stroked out?

Yes, turned wheel all the way to the right. Accidentally took the wrong hose off. I didn't take it directly off the cylinder, there is much easier access to a hose about half way between the tires and seat on the side of tractor hoses run on. Oil shot out everywhere towards the front of the tractor. I put that hose back on, took off the inside hose, and this time when I turned the wheel oil shot towards the back of the tractor away from the flow of oil towards the cylinder.

 

[Jabonee]

Yes, turned wheel all the way to the right. Accidentally took the wrong hose off. I didn't take it directly off the cylinder, there is much easier access to a hose about half way between the tires and seat on the side of tractor hoses run on. Oil shot out everywhere towards the front of the tractor. I put that hose back on, took off the inside hose, and this time when I turned the wheel oil shot towards the back of the tractor away from the flow of oil towards the cylinder.

10-4 thats definitely a bad cylinder.:thumbsup: