[Flatland Fox]

Best way to overcome the sorrow after seeing the Massey Harris depart is starting a new tractor restoration. Having the choice of a David Brown and a Fahr, I will start the restoration of the Aston Martin of the tractor world: the David Brown Cropmaster Diesel.

 

[Flatland Fox]

First thing to do was to push it inside the shop. No mean feat that I achieved using my MF65 and a tow bar which I tied to the back of the tractor.

I enjoy being a shade tree mechanic but winter in Segovia is harsh and having good lighting and heating inside, I can work many more hours.
First think to do is as many pics as possible. I always regret not having done more pics before starting a restoration.

 

[Jim in NC]

Sheet metal looks nice and straight. Look forward to the results of your hard work.

 

[Flatland Fox]

Thank you Jim.
David Brown was also the owner of Aston Martin Lagonda, that is the reason why Aston Martin cars are coded “DB” followed by a number, and these tractors have a higher quality than others. The finish is outstanding. No rough castings here. This was the first diesel engined DB tractor and Mr Brown was assessed by Sir Harry Ricardo, maybe the best british engine designer. Ricardo had a fascinating life, for example, he designed the engines of the first tanks. Look for him in wikipedia.

 

[Flatland Fox]

There are not many pics of this relatively rare tractor available, so I will post more than with the Massey Harris job.
Some of you may remember that some months ago I made a deal with the owner of a tractor museum: I had to restore a Massey Harris 102 junior and then I could keep the Cropmaster Diesel for me. The MH 102 jr. Is finished and this one is mine.
Restoring the MH I had the expenses needed restricted by the owner, but those restrictions will not apply here.

 

[Flatland Fox]

This tractor came from Caceres, a region of Spain with dry and good weather. Lots of farming there and the best ham in the world, belive me. This weather has preserved this tractor very well. Little rust here and there and lots of dirt but no manure...
Here is the engine with the bonnet removed and with the rocker cover cleaned. I have already removed the air filter, the battery supports and the exhaust.

And this is the aft side with all the bars and chains removed.

 

[Flatland Fox]

Removing the steering wheel was a real pain. The wheel has a big cavity covered by a plate. The plate can be opened prying with a screwdriver. But this arrangement lets water seep in. So the nut was seriously corroded and the wheel spline was fixed to the worm. No way to get it out and finally we had to heat seriously the remnants of the wheel to remove them. Now everything is ok but the worm steel has lost temper. I think I will replace it.

 

[Flatland Fox]

This the engine with the radiator removed short before taking out the fan screws.

 

[Flatland Fox]

Today I removed the rocker cover, the oil pan, the exhaust manifold, the intake manifold, the intake manifold, the cilinder head and piston number two.

ºThe crankshaft turns ok, there is no rust inside. The sleeve of the second piston is ok and the other sleeves also seem fine with very little ridge. But the second piston had the greasing ring broken and the piston itself was heavily scratched just over the pin hole.

My guess is that this tractor suffered a problem with the sleeves that led to their replacement. That´s why they look so fine and the piston so scratched.

 

[Flatland Fox]

Another pic of the block.

And the crankshaft. The conrod bushings are perfect.

 

[Flatland Fox]

Working pressure of the injectors is 175 atm. Yesterday I told Pepe to check the injectors because he has a funny machine to fix the working pressure. He called me today and told me that three injectors were stuck. I drove to his workshop, and they were completely stuck. I grabbed the thin stab with a vise and slowly pried the outer shroud. It worked. The injectors were just glued with solid fuel remnants. Otherwise they were in first class condition. Once cleaned they performed as new.
This week I have to look for some new pistons and rings in the net. I have measured the sleeve bore. It´s 92 mm, that makes 3 5/8”. I thought all Cropmasters Diesel had 3,5” bore. Anyway, it´s great news, because it seems 3,5 pistons are no longer available. 3 5/8 pistons are easy to find.

 

[Flatland Fox]

Some more pics which might be useful for anybody considering the same adventure...

 

[Flatland Fox]

A little mistery:
This tractor lacks the main serial number plate which should be riveted to the dashboard but there is a small plate on the PTO with the serial number:

Tractor number 11086 was built some time between 24/8/1950 and 10/11/1950. But this tractor has a motor block with 3 5/8” sleeves, which was introduced in serial number 15513 in 1952. Two years after 11806 was built.
Was the PTO housing changed and the serial plate with it?
Was the motor block changed to the CAD4-3 model with wider sleeves?
Well, go figure. Every tractor has a little story to tell.

 

[Flatland Fox]

This is the Lucas generator. It needed a bit of oil but seems otherwise ok. This was one of the first tractors with a 12 Volt electrical system.

 

[Flatland Fox]

And this is the fore tray. It is amazingly large. Seems to be asking for two more cilinders.
Tomorrow I will remove the weights bolted under this tray.

 

[Jim in NC]

Could the block have been bored for larger pistons at some time in the past?

 

[Flatland Fox]

Might be. But there was always a good supply of David Brown spare parts in Spain and I think it had been easier to change the block than finding a good reboring workshop in Extremadura 50 or 60 years ago. Who knows.
The sleeves are in very good condition. There is only some mild superficial corrosion at the lowest part of the inner surface, well below the sector frictioned by the piston rings. This is a pic of the sleeve before cleaning.

I think that the corrosion is related to the presence of water in the oil pan. It is a common problem in tractors with vertical exhaust. But I will fill the block with water before rebuilding the engine just to be sure there is no leak.

 

[Flatland Fox]

The motor block without pistons.

 

[Flatland Fox]

The starter motor. I suspect that a rodents family has been living in the flywheel housing...

 

[Flatland Fox]

You know, tractor restoring is mostly cleaning two tons of junk....

The starter motor is a CAV unit.