TLS problem

[Flat 10]

Good afternoon,
Bit flummoxed here have a 6920 with a bit of a problem. When you start it up TLS goes up to top then down to middle (where it should stop) and then goes to the bottom. In use it will work after a fashion as it constantly corrects itself and oil is clearly being supplied to sort the internal leak. As soon as you stop moving or the key is turned off it sinks to the bottom. A JD trained mechanic has tested the rams which appear fine with no internal leaks and taken off the TLS block and checked it over and can't find any obvious faults. He wonders if the pressure relief valve is the problem letting the oil out when it shouldn't. Not easy to test as radiator etc all off to access the TLS block. Any bright ideas @Phil P , @Tractortech @Timbo or anyone else. All inspiration gratefully received.

 

[Will 1594]

Bonnet up , battery off , under the battery platform is the height sensor. I would change that and see . 6620 was up and down like a ladies ( not a ladies )???I said w h o r e s , draws , height sensor cured it bit fiddly to get in under battery tray , bit of bending up ?

 

[Flat 10]

Bonnet up , battery off , under the battery platform is the height sensor. I would change that and see . 6620 was up and down like a ladies ( not a ladies )???I said w h o r e s , draws , height sensor cured it bit fiddly to get in under battery tray , bit of bending up ?

Did you get any error codes? None here except once when it said no movement detected.

 

[Flat 10]

Bonnet up , battery off , under the battery platform is the height sensor. I would change that and see . 6620 was up and down like a ladies ( not a ladies )???I said w h o r e s , draws , height sensor cured it bit fiddly to get in under battery tray , bit of bending up ?

Rad is out at the moment so should be straightforward. Was it expensive?

 

[Will 1594]

Rad is out at the moment so should be straightforward. Was it expensive?

No idea never asked needed one , and Gary knows not to take the pee

 

[Phil P]

Rad is out at the moment so should be straightforward. Was it expensive?

If it’s dropping with the ignition off your probably isn’t the position sensors, also if you’ve checked your cylinders the only other thing is the valve block. I’ll cut to the chase, if you have an internal valve block fault you may as well bite the bullet and replace it, I’ve never in all my time as a jd tech had any joy at getting a tls valve block serviceable! Unless it’s a solenoid valve I’d say it it’s toast, sorry to be the barer of bad news.

Usually after a lot of p!ssing about you can get it to a slow creep up or down but the valves never reseat properly unless you really lucky.

 

[Flat 10]

If it’s dropping with the ignition off your probably isn’t the position sensors, also if you’ve checked your cylinders the only other thing is the valve block. I’ll cut to the chase, if you have an internal valve block fault you may as well bite the bullet and replace it, I’ve never in all my time as a jd tech had any joy at getting a tls valve block serviceable! Unless it’s a solenoid valve I’d say it it’s toast, sorry to be the barer of bad news☹.

Usually after a lot of p!ssing about you can get it to a slow creep up or down but the valves never reseat properly unless you really lucky.

Well thanks for letting me know. No point in trying the PRV?

 

[Phil P]

Well thanks for letting me know. No point in trying the PRV?

Here you go, this will give you an idea of fow the system works (if you can read hydraulic Schismatics) if it’s dropping with the ignition off it can only be check valve no13, pressure relief valve no5 bleed valve no2 or a cracked housing. Trouble is no parts (other than solenoids) are available so Unless you can repair the valve it’s knackered.

 

[Flat 10]

That is indeed a bit beyond me. I will show you the JD parts diagram I was looking at earlier.
Thanks

 

[Flat 10]

I think we were looking at 14 as the PRV which could be replaced. You obviously haven’t had any success with cleaning it all and putting it back together. Shame it’s such an arse to get to. Thanks for all your help Phil, shame it’s not more serviceable.

 

[Tractortech]

Now Then..
Have you looked in the SFA controller via the dash panel for any codes or just waiting for them to pop up??
I've had 2 valve blocks out without removing the radiator. It's a scrat but they come out under the chassis. You'll need ingenuity and tools to get the round pin hole type valves out. I hot washed them internally, cleaned everything else in degreaser and blew it with air. Brake failure was the cause both times. Both valves worked OK afterwards..

 

[Flat 10]

Now Then..
Have you looked in the SFA controller via the dash panel for any codes or just waiting for them to pop up??
I've had 2 valve blocks out without removing the radiator. It's a scrat but they come out under the chassis. You'll need ingenuity and tools to get the round pin hole type valves out. I hot washed them internally, cleaned everything else in degreaser and blew it with air. Brake failure was the cause both times. Both valves worked OK afterwards..

Thanks. Rad is off now anyway. I’m the second owner of the tractor and I haven’t looked at brakes but the tractor was on a ring fenced farm with basically zero road work so no suspected brake problems.

 

[Flat 10]

Ok so mechanic thought had found problem, replaced o'ring put back on and its just the same. Looks like a new valve is the solution ££££
Thanks for all help. Mechanic as gutted as I was......

 

[manttys]

Just buy a used valve block for 450 pounds and forget the problem. Mine is doing pretty much the same, but sometimes it stays risen after a ride, sometimes not. But always drops (after alignment) when tractor is started. I can't hear that pump would be constantly turning on and off again, so it doesn't bother me too much, but I like when things work as they should. A new one is about gbp 900.

 

[manttys]

Here you go, this will give you an idea of fow the system works (if you can read hydraulic Schismatics) if it’s dropping with the ignition off it can only be check valve no13, pressure relief valve no5 bleed valve no2 or a cracked housing. Trouble is no parts (other than solenoids) are available so Unless you can repair the valve it’s knackered.

When I open bleed valve no 7, tractor rises. So basically there is a chance that lover chamber gets oil pressure when it shouldn't and messes the balance between the two. It there was a problem with upper chamber, tractor wouldn't stay risen for days.

 

[Flat 10]

Just buy a used valve block for 450 pounds and forget the problem. Mine is doing pretty much the same, but sometimes it stays risen after a ride, sometimes not. But always drops (after alignment) when tractor is started. I can't hear that pump would be constantly turning on and off again, so it doesn't bother me too much, but I like when things work as they should. A new one is about gbp 900.

Quoted £1500! Here less 10% discount.

 

[Tractortech]

Have you checked the accumulator pressure and for leaks??

 

[manttys]

Quoted £1500! Here less 10% discount.

Give the part no, I will double check

 

[Flat 10]

Have you checked the accumulator pressure and for leaks??

No. Surely that would only effect ride quality rather than letting it fall down every time it reaches the mid point. There are no error codes and it calibrates fine.

 

[Flat 10]

Give the part no, I will double check

Number I have is AL155982 which is sub for AL151350......
I think the valve is common between late 10 series and all 20 series. 30 series are different. So i'm told anyway. Nick Young doesn't have one and nor do burdens.