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JCB 712 identification and parts support

Mobilewrench

Senior Member
Joined
Feb 26, 2020
Messages
380
Location
Kona, hawaii
I'm gonna say straight off; no idea of the serial number.
The data plate is missing. Anyone know if it is stamped on the frame somewhere? Is it possible to reverse engineer it from the engine or trans data plates?

Anyway...
One of my core clients found this unit and was told they could just have it. I honestly don't know what they would even want it for. I suppose that it might come in handy to slow down bed damage on their on road dump truck. Other than that it looks like more trouble than it is worth.

He decided that he wanted it. So he and his foreman spent all of yesterday just trying to get it to start. When they failed it became my problem.

This morning I went up to the site fairly well armed with good intentions and a bad attitude, ("grrrr... Why would you acquire something broken just on the assumption that I can fix it?")

No radiator, no fan, no fan shroud... Soooo much garbage and water in the bed.

I generally take baby steps in these situations. I don't know how long it has been sitting there so I am not even going to try to determine if the fuel is good.

So, external fuel source, electric fuel pump, leave the fuel return open. (Perkins, 6 cylinder, by the way). Crack a few injector lines and crank. I am getting fuel to the injectors but Just a little bit of smoke and no start.

The diesel trinatry is fuel, air compression. I have fuel and I cannot easily bar over the engine (even though the starter is spinning the engine pretty impressively) so I seem to have compression. That leaves air.

I pulled the intake hose off of the turbo and found that the impeller wouldn't turn by hand. Then I pulled another plate off of the intake manifold to let the engine breathe without the turbo. Damned thing fired right up.

I am going to skip a lot of the labor pains here. Hydraulics seem okay, park brake line has rusted through, etc.

For some reason, the transmission control is missing from the machine. I asked the people on site. They had no idea where the radiator even was.
 

sfrs4

Senior Member
Joined
Jul 22, 2013
Messages
697
Location
Great Britian
Occupation
parts admin
This isn't gospel by any means but from what I can see the original part 4200386 has been superseded by a wiring harness change and a different part number gear selector unit, you might be able to find a good used/second hand original unit?
new harness 242156
gear change unit 280/38500
 

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