MF30 Instant reverse tractor Sudden failed to move

[jkk04]

A couple weeks ago, my beloved 1970 MF30 industrial tractor suddenly failed to move forward or backward while scraping on the ground.
The tractor has Perkin AD204 4 cylinders diesel engine.

The tractor has no indication of any noises nor wrong movement before it happens.

Only I suspect there was no fluid circulation in the transmission internally causing no pump and no supply of the fluid to the torque converter.

I replaced the transmission oil pump because of the seal failure and fluid and sump filter 7 years ago.

Ever since the tractor works without any problem.

Again, I removed the sump pan and cleaned some sludge and filter then added new fluid.

I thought the sludge was to block the fluid circulation through the sucking pipe to the oil pump.

But it did not help.

So, I removed the 1/8" pipe plug at the top of the transmission then connected a PSI gauge for PSI testing according to the service manual.

The pressure gauge shows only 40 PSI.

It should be between 150 to 160 PSI.

Is the pump failing?

I replaced the OEM oil pump about 7 years ago and it has served me for the last 35 years that I couldn't give up this lovely tractor.

Any suggestion from savvy members in here will be much appreciated

Jkk

 

[Dman1981]

Quick question does scraper
Still
Go up and down
If it
Does. you could have broke coupler from trans to pinion which can be replaced they left hand side cover

 

[jkk04]

No, it does not go up or down that means the 3-point hitch is not working neither.
Thanks

 

[Dman1981]

Three point works off trans
So are there any little pieces in the screen

 

[jkk04]

Three point works off trans
So are there any little pieces in the screen

No. It was only sludge in the screen and pan.
Thanks.

 

[Dman1981]

iOS screen still intack
So the two bolt heads on side of trans regulate fwd and rev pressure are
Spring
Loaded with a spool valve a pin inside shims under springs for pressure top bt
Is to cooler and filter screen in filter also

 

[Dman1981]

My typing sucks fat fingers

 

[jkk04]

iOS screen still intack
So the two bolt heads on side of trans regulate fwd and rev pressure are
Spring
Loaded with a spool valve a pin inside shims under springs for pressure top bt
Is to cooler and filter screen in filter also

The procedure you meant to above is for transmission pressure test when the pressures are normal range 150-160PSI.

But the current pressure on the transmission is only 40PSI.

Does it indicate the oil pump failure?

Thanks again

 

[Dman1981]

More than likely but the crud is everywhere could have broken sealing rings also I would pull them make sure they are not stuck pins will stick in plunger

 

[jkk04]

Updating...
Split the tractor then discovered the torque converter main back plate for engine flywheel attached.
It is complete broken middle of section.
Unbelievable
Finding and waiting the answer for the plate through the local MF dealer.