3-Point Hitch help please i have lost all hydraulic pressure on my MT1601D

ch85st · Jun 3, 2018

Dave M7040 said:
Be careful using a pressure gauge. You do NOT want to hook it at the end of a line that might not have the relief valve between the pump and the gauge.

I suggest you first see if your pump can deliver a reasonable volume of oil without worrying about the pressure. Come up with a temporary line connected to the pump output with an open hose which you can direct into a clean bucket so you can reuse the oil. This would be a connection at the put outlet and certainly before the hydraulic block.

The pump should be able to deliver at least 6 US gallons per minute or 22 liters per minutes with the engine at full speed.

If it does not deliver close to that volume you either have a restriction in the suction line, screen or filter. Or a serious air leak into the pump suction.

A pump which will deliver the proper volume will usually deliver the oil at pressure as well so this is a test you can do without a pressure gauge.

There should be oil constantly returning to the reservoir from the FEL valve. A hose in the wrong place does weird things if you removed any or all hoses.

Dave M7040

Thanks again

No i havent removed any hoses on the control valve on the FEL

I will try to test the pumps capacity the way you suggested.
and there are 6 connections on the Control valve for the FEL And no power steering on this small tractor, On last picture one can see the bolt and high pressure line mounted on top and in to the Hydraulic Block

Kernopelli · Jun 4, 2018

ch85st said:
I will try to test the pumps capacity the way you suggested.

Your pump should be 3.4GPM/12.9L/min

Industrial Toys · Jun 4, 2018

No argument. I am trying to learn something. But the oil is not always flowing back to reservoir at low pressure, if a circuit has been chosen and now the oil is returning from a cylinder, and if at end of stroke, some relief kicks in. At that point, I guess the oil going back to the reservoir is going via relief but from no other place.

Kernopelli · Jun 4, 2018

ch85st said:
I will try to test the pumps capacity the way you suggested.

Your pump should be 3.4GPM/12.9L/min

The way your FEL is plumbed it is in line after the 3 point hitch and is the last demand on the circuit,. If you don't have pressure at the 3 point hitch, the problem isn't in the FEL control valve or its relief. I believe you either have a suction/supply issue or a pump issue....here again, you really should put a pressure gauge on it.

I'm curious, does the 3 PH or FEL cylinders move even a little when the contols are cycled?

lens12 · Jun 5, 2018

I'll guarantee you the problem is the pump. First ---the pump was rebuilt, they are not rebuildable. They are a throw away pump. Second ---You are using 80 gear oil. It works good when it is cold, but once it warms up it becomes thinner & quits working. third--, you have 2 separate systems & both are malfunctioning. What are the odds of both systems working & both quitting at the same time. You can put a pressure gauge on the bucket loader hose & dead head it. The valve has a relief valve. If it didn't you'd wreck the pump every time you extended the cylinders all the way. Surplus center has reasonably priced pressure gauges.
It is not the loader relief valve. You do not have power beyond so all the OUT flow is going to the 3 point if the relief is stuck open or closed. You would also need a malfunction in the 3 point system too.

Dave M7040 · Jun 5, 2018

lens12 said:
I'll guarantee you the problem is the pump. First ---the pump was rebuilt, they are not rebuildable. They are a throw away pump. Second ---You are using 80 gear oil. It works good when it is cold, but once it warms up it becomes thinner & quits working. third--, you have 2 separate systems & both are malfunctioning. What are the odds of both systems working & both quitting at the same time. You can put a pressure gauge on the bucket loader hose & dead head it. The valve has a relief valve. If it didn't you'd wreck the pump every time you extended the cylinders all the way. Surplus center has reasonably priced pressure gauges.
It is not the loader relief valve. You do not have power beyond so all the OUT flow is going to the 3 point if the relief is stuck open or closed. You would also need a malfunction in the 3 point system too.

Don't forget this line in one of the owner's posts:

"I will see if its possible to find one of those Pressure Gauge here in Bulgaria"

He likely does not have the easy option of a new pump.

Dave M7040

markct · Jun 5, 2018

I just went thru this with my 1801, plenty of pump flow but seemed unaffected by the movement of the valve, was running it with the lift cover off and watching to see if spool moved etc. Finally took the valve all apart, actually a couple times first time I missed the check valve under the large flat head screw, and cleaned them all and oiled and reassembled and finally it works!

ch85st · Jun 6, 2018

Kernopelli said:
Your pump should be 3.4GPM/12.9L/min

Thank you for that information i will test how much my pump gives

ch85st · Jun 6, 2018

markct said:
I just went thru this with my 1801, plenty of pump flow but seemed unaffected by the movement of the valve, was running it with the lift cover off and watching to see if spool moved etc. Finally took the valve all apart, actually a couple times first time I missed the check valve under the large flat head screw, and cleaned them all and oiled and reassembled and finally it works!

Thanks for your reply
Do you mean the large flat head screw on the Control valve inside the Hydraulic Block?

i didnt remove that one as well when i had it off and checked it , Bugger.

ch85st · Jun 6, 2018

Kernopelli said:
Your pump should be 3.4GPM/12.9L/min

The way your FEL is plumbed it is in line after the 3 point hitch and is the last demand on the circuit,. If you don't have pressure at the 3 point hitch, the problem isn't in the FEL control valve or its relief. I believe you either have a suction/supply issue or a pump issue....here again, you really should put a pressure gauge on it.

I'm curious, does the 3 PH or FEL cylinders move even a little when the contols are cycled?

The only movement i can get is if i jump on the bucket to get the tilt cylinders to extend a little maybe 2 cm then i can retract them but Slowly.
and no movement at all on the 3 Point

ch85st · Jun 6, 2018

lens12 said:
I'll guarantee you the problem is the pump. First ---the pump was rebuilt, they are not rebuildable. They are a throw away pump. Second ---You are using 80 gear oil. It works good when it is cold, but once it warms up it becomes thinner & quits working. third--, you have 2 separate systems & both are malfunctioning. What are the odds of both systems working & both quitting at the same time. You can put a pressure gauge on the bucket loader hose & dead head it. The valve has a relief valve. If it didn't you'd wreck the pump every time you extended the cylinders all the way. Surplus center has reasonably priced pressure gauges.
It is not the loader relief valve. You do not have power beyond so all the OUT flow is going to the 3 point if the relief is stuck open or closed. You would also need a malfunction in the 3 point system too.

Thanks again for your Information

i will try what you have suggested before and measure how much the pump deliverers in 1 minute

I have one Bulgarian Dealer in small tractors saying he has a functioning used Hydraulic Pump for my tractor (well being Bulgaria i must check it first so it fits), will buy that one if my Pump dont deliver the expected 12.5 liters/minute

markct · Jun 7, 2018

ch85st said:
Thanks for your reply
Do you mean the large flat head screw on the Control valve inside the Hydraulic Block?
i didnt remove that one as well when i had it off and checked it , Bugger.
View attachment 557416 View attachment 557417

Well I spoke too soon, worked for a day and then stopped, guess I gotta disassemble it again and see what's going on

ch85st · Jun 7, 2018

markct said:
Well I spoke too soon, worked for a day and then stopped, guess I gotta disassemble it again and see what's going on

exactly what mine did, works for a few hours after changing to new oil and fiddling with everything, then stops (well thats how it was) now its completely Dead

Let me know if you find the problem,
i am going to get the used pump from the Small tractor Dealer here in Bulgaria and see if that by any chance helps he wants 200€ (a fortune here in Bulgaria, for some its a Months wages)

markct · Jun 10, 2018

ch85st said:
exactly what mine did, works for a few hours after changing to new oil and fiddling with everything, then stops (well thats how it was) now its completely Dead
Let me know if you find the problem,
i am going to get the used pump from the Small tractor Dealer here in Bulgaria and see if that by any chance helps he wants 200€ (a fortune here in Bulgaria, for some its a Months wages)

I don't think the pump is your issue, on mine I ran it with the lift cover propped up and watched to be sure the valve moved etc and oil flow never stopped coming from the return. If it was the pump not pushing oil it would have stopped or slowed, plus my loader works fine and it is in series ahead of the three point. Hopefully the new valve solves it, I'm confident the problem is within that valve

ch85st · Jun 12, 2018

markct said:
I don't think the pump is your issue, on mine I ran it with the lift cover propped up and watched to be sure the valve moved etc and oil flow never stopped coming from the return. If it was the pump not pushing oil it would have stopped or slowed, plus my loader works fine and it is in series ahead of the three point. Hopefully the new valve solves it, I'm confident the problem is within that valve

Well i gave up and have now ordered a new Pump, it will arrive in about a week, as nothing works on my MT 1601D nothing moves on the FEL or the 3 Point, i suspect it might be that the pump deliver oil but not enough to build up the pressure, if that dont help i will have to see if i can find a new valve for the Hydraulic Block. (Or a new Tractor

)

Eagleview · Jun 14, 2018

Relief valve sticking open when hot ?
The black oil is a mystery, is your crankcase oil level getting lower ?
Does this black oil smell burnt ? If it is actually burnt hydraulic oil, you have serious problems .

ch85st · Jun 14, 2018

Eagleview said:
Relief valve sticking open when hot ?
The black oil is a mystery, is your crankcase oil level getting lower ?
Does this black oil smell burnt ? If it is actually burnt hydraulic oil, you have serious problems .

The oil is no longer Black after cleaning out all the black crap at the bottom of transmission, there was at least 1 - 2 cm of it. its clear and fine now. im sure that what happened was the screen on the filter broke and all the black crap mixed in with the oil.
I have now how ever tested the old Pump, it gave about 9 Liters at 1500 rev during 1 minute so im not so sure its the pump.
Bugger i just ordered a new one

ah well good to have a spare.
Im close now to giving up

Oil is flowing to the Hydraulic Block But nothing moves , just had the piston to lift arms out and no oil is coming in to the cylinder no matter what i do.
Oil is flowing to and from FEL but nothing moves.
There must be a fault in the Control valve in the Hydraulic Block that releases the oil before any pressure can be built any where. thats the only thing i can think of.
Ah well time to find an expert and have the tractor sent there so some one else can get grey hairs

Eagleview · Jun 14, 2018

ch85st said:
The oil is no longer Black after cleaning out all the black crap at the bottom of transmission, there was at least 1 - 2 cm of it. its clear and fine now. im sure that what happened was the screen on the filter broke and all the black crap mixed in with the oil.
I have now how ever tested the old Pump, it gave about 9 Liters at 1500 rev during 1 minute so im not so sure its the pump.
Bugger i just ordered a new one ah well good to have a spare.
Im close now to giving up Oil is flowing to the Hydraulic Block But nothing moves , just had the piston to lift arms out and no oil is coming in to the cylinder no matter what i do.
Oil is flowing to and from FEL but nothing moves.
There must be a fault in the Control valve in the Hydraulic Block that releases the oil before any pressure can be built any where. thats the only thing i can think of.
Ah well timer to find an expert and have the tractor sent there so some one else can get grey hairs

A stuck relief valve or a broken relief valve spring in your valve block will cause these issues .
Oil will just go back to tank and not do any work if this is the problem .
Is the relief valve an external adjustable type, which can be unscrewed from the block ?
Can you upload a picture ?

ch85st · Jun 14, 2018

Eagleview said:
A stuck relief valve or a broken relief valve spring in your valve block will cause these issues .
Oil will just go back to tank and not do any work if this is the problem .
Is the relief valve an external adjustable type, which can be unscrewed from the block ?
Can you upload a picture ?

The FEL is connected on the side of the Hydraulic block (Where the external relief valve used to be)
And the return from FEL goes in to the Filler hole on Gearbox (that one gives oil all the time the tractor is running now, NOT sure but i think it didnt give oil in return unless i moved the leavers before)