MF6840 Error Code T151 - one for the MF experts!

[Farma Parma]

That would figure as it has a mind of its own..
Torque Curve 2 is never active when iam drilling with Combi using PTO
Yet its working when in 3rd Gear Ploughing....

 

[NZ Tech]

had this fault on a 6475 before found out it was the wiring harness at the rear of the cab that was at fault the corrugated conduit had rubbed through the wires just below the multi plug worth a look this conduit causes many a problem on MF's especially if dust gets inside it there was a tech bulletin issued about it

This is a fault of all machines with conduit... It should be smooth.

 

[James]

That would figure as it has a mind of its own..
Torque Curve 2 is never active when iam drilling with Combi using PTO
Yet its working when in 3rd Gear Ploughing....

had a look today on mine
cutting hedges in 2nd gear is in torque curve 1 jump into 3rd to drive to another bit quicker goes into tc2 load figure ranging from 28 to 40 odd
baling in 2nd in tc1 but up to 100 load figure

 

[Oh Deere]

Hi,

I'm usually repairing the green brand of tractors so my experience of these Masseys is limited. I was helping a mate out this weekend who has an MF6840 Dyna-6 with a perkins engine. I noticed whilst driving the tractor it was flashing the brake pressure symbol and error code T151 was present. I questioned him to see if he'd seen the code before, he said that mechanics from an MF dealership had been out to the tractor and tried to solve the problem and had been unsucessful and spent plenty on parts! So my aim is to solve it once and for all. I've a tech manual for the tractor and have read up on how the system operates and cannot really understand why they replaced the following if the fault isn't with these components, especially as it is stuff they could test!

New pressure sensor, could have done a resistance check rather than replace?

HP brake block itself, unsure whether this would include the relief valve or accumulator or internal suction screen

New brake switches - if they checked continuity they could have isolated these parts.

The code relates to: Sudden drop in HP braking pressure (pressure measured by sensor less than 78bar) with no braking.

This to me suggests either a bad connection between sensor signal pin and Transmission control unit 1 (pin 35) or more likely a dodgy accumulator not storing charge and therefore pressure is dropped quickly after being initialised?

Could anyone advise me as to whether I'm on the right tracks or any past experiences of the same problem would be great!

Thanks in advance,
jd6820

We work mainly on Claas machines with the same back end.
There are two problems that we have come up against recently,when the tractor is started the high pressure brake system is charged.There is a solenoid valve in the charge block along with your pressure sensor.
On the Claas the sensor works at 4.5 volts with a voltage reducer in the cab for that particular circuit only.They will become faulty and produce 12 volts at the sensor.
Also putting gauges on the high pressure brake circuit without putting a flow metre on the ccls pump will give you false information.We have had worn pumps giving good pressures and flow at 2000RPM and able to build pressure for standby at tickover but no flow not being able to charge brake circuit at tickover.
Claas test info for pump is at high rpm , it took us a bit to understand why we could not charge the brake circuit as test figures for pump where up to spec but pump was knackered.
Remember to pump brakes with engine stopped until pedal goes soft to release pressure in accumulator
Could also be a can line error ,corrosion in plugs.
Poorly adjusted brake switches will cause this error or someone riding the brake pedals

 

[clem dog]

had a look today on mine
cutting hedges in 2nd gear is in torque curve 1 jump into 3rd to drive to another bit quicker goes into tc2 load figure ranging from 28 to 40 odd
baling in 2nd in tc1 but up to 100 load figure

how can you tell this?

 

[grumpy]

ive been pondering this,any good?

http://www.vapormatic.com/_assets/documents/TEXA_Diagnostics_and_Osiloscope_leaflet_25-7-2011.pdf

 

[Oh Deere]

ive been pondering this,any good?

http://www.vapormatic.com/_assets/documents/TEXA_Diagnostics_and_Osiloscope_leaflet_25-7-2011.pdf

We have the Texa system.
Its a good diagnostic tool.works very well with John Deere.

 

[Pheasant Surprise]

We have the Texa system.
Its a good diagnostic tool.works very well with John Deere.

How much are they? Recall talking about this on another thread ages ago. Need to do a lot of diagnostic work to make it worthwhile as they are a bit on the expensive side from memory.

Edit: yep sorry found the thread now, it's on the other place (me bad)

http://farmingforum.co.uk/forums/showthread.php?1928-Tractor-Diagnostics-and-Laptop-Software

 

[James]

how can you tell this?

sorry I think I'm getting my threads mixed up on the wee keypad on the steering column press the up button for a couple of seconds will bring up another menu. at the bottom right select ok and it 'll tell you there

 

[Farma Parma]

Bugger that's me Secret Menu Secret out...

 

[jd6820]

Just a quick update, accumulator seems fine so the problem is clearly not here, the supply voltage to the sensor is the correct 4.5-5v so no worries there, I've not had chance to check the signal line back to the TCU so this will be my next job when I get chance, along with a flow and pressure check as suggested.

 

[spitfire]

Just a quick update, accumulator seems fine so the problem is clearly not here, the supply voltage to the sensor is the correct 4.5-5v so no worries there, I've not had chance to check the signal line back to the TCU so this will be my next job when I get chance, along with a flow and pressure check as suggested.

hi we had similar problems with 6400 series massey unable to fix it so px it for newer one still have similar problems with new one,they seem to have a lot of problems due to the orbiter circuits

 

[Georgejlew]

The error code loves to come up there is a option on wintest to switch the light off, normally it is the prv in the high pressure block blowing to early and needs screwing up a bit, however I often have this code on my tractor as the brake pedal switches are not adjusted correctly, I have mine like this as it prevents the 4wd braking coming in under light braking and also means the air brakes do more before the tractor brakes come in, it’s not a truly serious issue more annoying switch it off and on again and it will reset the system

 

[Southmec32]

I am currently repairing hp circuit failures on 7600 and 7700 tractors but would have to double check if it is the same . Does the fault come on on startup or once you have been working for a while. The hp braking runs at lower relief pressure around 150 bar . On a 7700 this pressure is built up by the filling solenoid till the relief blows on startup and you can hear it and is the best time to test the relief valve . Some of these have been set to low from factory and need screwed ip on the hpb block. Also the circuit pressure should not fall below 50 or 70 bar i cant quite remember or it will bring up the light and error code. It will fall below if there is cicuit pressure leakage within so many braking aplications. The accumulor should be charged to 49 bar. Also some machines need a software upgrade as some only read off 1 brake sensor so if brakes are uncoupled it work read every brake aplication. This is for a 7700 and would have to check if it is same for a 6400 but will be the same princable i think

 

[Yorkshire dano]

Any updates on the code? My 6499 does it from time to time if I don’t press brakes for w while

 

[Xealuz]

I am currently repairing hp circuit failures on 7600 and 7700 tractors but would have to double check if it is the same . Does the fault come on on startup or once you have been working for a while. The hp braking runs at lower relief pressure around 150 bar . On a 7700 this pressure is built up by the filling solenoid till the relief blows on startup and you can hear it and is the best time to test the relief valve . Some of these have been set to low from factory and need screwed ip on the hpb block. Also the circuit pressure should not fall below 50 or 70 bar i cant quite remember or it will bring up the light and error code. It will fall below if there is cicuit pressure leakage within so many braking aplications. The accumulor should be charged to 49 bar. Also some machines need a software upgrade as some only read off 1 brake sensor so if brakes are uncoupled it work read every brake aplication. This is for a 7700 and would have to check if it is same for a 6400 but will be the same princable i think

I've got a MF 6616 with a t1.53 code, sounds like a problem similar to this post. I'm able to get it to repeat the problem by pumping the brakes 10-12 times, it then sounds like a prv is spilling and I get a red light that persists until I key off and back on. with it repeating reliably after pumping the brakes, it doesn't seem like a wiring or pressure sensor problem. It will also occur after working in the field for a while, not necessarily connected to the hitting of the brakes. Any advice or experience on this issue would be greatly appreciated.

 

[Steevo]

I’m guessing either the tractor or @jd6820 has probably left the farm now…..

 

[Steevo]

Did you fix it @jd6820 ?

 

[Xealuz]

Not sure if this was for me or @jd6820 but I did fix my issue. I started a new thread, link below, that discusses the fix.
mf-6616-error-code-t153-one-for-the-mf-experts

 

[jd6820]

Exactly as above, accumulator replaced. Problem solved.