[Flatland Fox]

Next project: David Brown Cropmaster Diesel.

These are the threads. Probably you all are quite used to do these things with perfect results, but my performance doing threads up to now was rather miserable...

www.antiquetractorsforum.com

Couple of people said they sloshed some sand and gravel around inside to clean the tank before pouring that tank lining stuff in; bit it seems like a bodge hoped you had a better way to do it properly?

The theory of how to clean the inside of a tank could fill a whole book!
These are the procedures I have done so far in several different tanks:
First thing to do is to take a look inside the tank checking the amount of dirt, rust, pitting, foreign objects, holes, etc. Take your time and use a flashlight; fiberscopes are also useful and they are not expensive nowadays. Do not forget to check whether the filler neck has a rim inside the tank, because if it has one it will be quite difficult to take out completely whatever you use to clean it if it is a loose matter like sand. Clean the inside with water and some sort of strong cleaner for oily/greasy stuff. Best advisor for the stuff to use is your own wife. This will clean and dissolve most fuel remnnants which might creat fumes. Rinse it several times. If the bottom is seriously pitted, forget about cleaning it and go to a welders to replace the whole bottom and bumps if there is any. That happened to my MF65. If there is dirt and light rust with no pitting then I put a piece of chain about 2 cm wide and half a meter long inside and another piece of a thinner chain that can reach all the angles of the tank, pour some generous amount of rust solvent of your choice (not too flammable, please) and then you can play the fool shaking it for hours or tie it to a rear rim of a jacked up tractor, start it up, engage the first gear and go for a beer with tapas while it cleans. Check the progress between beers until the inside looks pretty, remove the chains, drain the solvent, rinse with water and whatever your wife tells you, let it dry thoroughly and once you are satisfied, pour some fuel or engine oil and shake it in a sportly manner and then go to celebrate it with with another beer. If the tank shows strong corrosion but you are convinced that the metal thickness is strong enough, once you have cleaned the inside, consider to use a gas tank sealer. But if you see the sheet metal weakened or even holed, the welders is your only option.
This what I actually do, but, remember, I am not a pro, just a shadow tree mechanic…

 

[User27]

The theory of how to clean the inside of a tank could fill a whole book!
These are the procedures I have done so far in several different tanks:
First thing to do is to take a look inside the tank checking the amount of dirt, rust, pitting, foreign objects, holes, etc. Take your time and use a flashlight; fiberscopes are also useful and they are not expensive nowadays. Do not forget to check whether the filler neck has a rim inside the tank, because if it has one it will be quite difficult to take out completely whatever you use to clean it if it is a loose matter like sand. Clean the inside with water and some sort of strong cleaner for oily/greasy stuff. Best advisor for the stuff to use is your own wife. This will clean and dissolve most fuel remnnants which might creat fumes. Rinse it several times. If the bottom is seriously pitted, forget about cleaning it and go to a welders to replace the whole bottom and bumps if there is any. That happened to my MF65. If there is dirt and light rust with no pitting then I put a piece of chain about 2 cm wide and half a meter long inside and another piece of a thinner chain that can reach all the angles of the tank, pour some generous amount of rust solvent of your choice (not too flammable, please) and then you can play the fool shaking it for hours or tie it to a rear rim of a jacked up tractor, start it up, engage the first gear and go for a beer with tapas while it cleans. Check the progress between beers until the inside looks pretty, remove the chains, drain the solvent, rinse with water and whatever your wife tells you, let it dry thoroughly and once you are satisfied, pour some fuel or engine oil and shake it in a sportly manner and then go to celebrate it with with another beer. If the tank shows strong corrosion but you are convinced that the metal thickness is strong enough, once you have cleaned the inside, consider to use a gas tank sealer. But if you see the sheet metal weakened or even holed, the welders is your only option.
This what I actually do, but, remember, I am not a pro, just a shadow tree mechanic…

Thanks for the reply, somebody should write that book I would have bought a copy!

The chain seems an excellent choice of abrasive. However my DB25 still runs TVO; the outer tank is solid no holes but the smaller inner tank is shot so there's loads of rusty flakes and whatnot in there.

I could stand to lose the inner tank and just have one large tank for paraffin mix; then I could simply drain the carb and fill the filter bowl with petrol for starting it.

I think it probably has to be opened up somehow I just don't know where to start; you might be right it's a professional welder job chop the bottom out to clean it all nicely then might as well replace it with new metal?

Perhaps avoiding the two threaded fittings on the bottom that suit the solid fuel lines.

Presumably this isn't something that can have a hole cut in the under side to clear out the inside and then a plate soldered over it? It's not like anybody would see it after its fitted.

Excited to see your next batch of pictures now that the rad decision is made and the front is on.

Regards, Alex

 

[Flatland Fox]

Two tank outlets because it was originally a TVO engine before conversion no doubt; so the little tank to start it on petrol before switching over to the cheap stuff.

Paint wise I find that a good etch primer before the filler primer gives the desired results.

I appreciate very much your comments.
Whatever I use, I always try to apply thin layers on the sheet metal. I guess it also depends on the climate of your area, but here in Segovia, temps go below -15ºC in winter to over 40ºC in summer. Such a temperature span will blast whatever you use if you apply a thick coat: primers, fillers, paints….
As far as I have experienced, etch primers are a fantastic choice for castings and for sheet metal in a perfect shape not needing any sort of filler. If you have to apply a thick patch of filler it will eventually flake off in the first heat wave no matter what you put below.
That is why I try to hammer away all the bumps no matter how small. Just to avoid the filler as much as I can. And if something cannot be repaired with the hammer or welder, I can even let it there as a silent witness of the hard life of the tractor.

 

[Flatland Fox]

Thanks for the reply, somebody should write that book I would have bought a copy!

The chain seems an excellent choice of abrasive. However my DB25 still runs TVO; the outer tank is solid no holes but the smaller inner tank is shot so there's loads of rusty flakes and whatnot in there.

I could stand to lose the inner tank and just have one large tank for paraffin mix; then I could simply drain the carb and fill the filter bowl with petrol for starting it.

I think it probably has to be opened up somehow I just don't know where to start; you might be right it's a professional welder job chop the bottom out to clean it all nicely then might as well replace it with new metal?

Perhaps avoiding the two threaded fittings on the bottom that suit the solid fuel lines.

Presumably this isn't something that can have a hole cut in the under side to clear out the inside and then a plate soldered over it? It's not like anybody would see it after its fitted.

Excited to see your next batch of pictures now that the rad decision is made and the front is on.

Regards, Alex

If I had your problem, I would go the big way and open the tank like this:

I would do whatever is required inside including a new inner tank the shape that serves you better because nobody is going to see it (I did not draw the second filler neck) and weld a new bottom strong enough to outlive you. It is a very easy job for a good welder or bodywork car mechanic.
And remember to clean the fittings of the bottom. We spend lots of time cleaning the tank and then we forget to clean the outlets. It is amazing the amount of dirt they collect.
TVO tractors are for tough daring guys….

 

[User27]

The TVO block has small external frost cracks in the usual places; the oil and water isn't mixing internally. So it's not overly urgent but I picked up a seized 25d diesel engine with a view to doing the sleeves and swapping out just the block (which appear identical).

However, the replacement block appears to have a lot if not all the diesel bits still attached; so at some point I will have to make the decision between TVO and diesel. Leaning towards TVO since it's more original and I have most of an IBC full of paraffin to boot.

Interesting that your block was replaced with one of the later batch with the different oil filter; I think that happened to quite a lot of them.

 

[Flatland Fox]

The TVO block has small external frost cracks in the usual places; the oil and water isn't mixing internally. So it's not overly urgent but I picked up a seized 25d diesel engine with a view to doing the sleeves and swapping out just the block (which appear identical).

However, the replacement block appears to have a lot if not all the diesel bits still attached; so at some point I will have to make the decision between TVO and diesel. Leaning towards TVO since it's more original and I have most of an IBC full of paraffin to boot.

Interesting that your block was replaced with one of the later batch with the different oil filter; I think that happened to quite a lot of them.

The initial Cropmaster cracked so badly that insurances covered the replacement!
One of the reasons was that they lacked the expansion discs, the other reason was the lack of antifreeze fluid. The 25 D might be very similar but the block might be bored for 3.75 in. pistons instead of the 3.5 in pistons used in the initial VAK Cropmasters.
If the cracks are not leaking you might consider to weld them, but welding cast iron requires skill and special materials. If there is absolutely no leak, you might use a cold weld from Nural or similar and forget about them.

 

[User27]

The initial Cropmaster cracked so badly that insurances covered the replacement!
One of the reasons was that they lacked the expansion discs, the other reason was the lack of antifreeze fluid. The 25 D might be very similar but the block might be bored for 3.75 in. pistons instead of the 3.5 in pistons used in the initial VAK Cropmasters.
If the cracks are not leaking you might consider to weld them, but welding cast iron requires skill and special materials. If there is absolutely no leak, you might use a cold weld from Nural or similar and forget about them.

Love your mentality towards "silent witness of the hard life of the tractor" I forgot to mention this is very much my perspective.

If it's bored differently could I still use the head etc off my TVO engine and just swap the block+pistons+crank?

No idea if the cams are different for the 25d or not.

Anyhow I think the fuel tank comes some time before the block given that it currently runs using a small auxiliary tank.

I have been told block repair would need to be stitched rather than welded to make a proper job of it. Also been told that the sides should be held together with a threaded rod with a large washer and nut either side; however the rod will not fit between cyl2 and cly3 so you have to weld a bit of threaded rod to each end of a flat bar that goes between the two liners.

That said, it's a very slow weeping leak so I just top the rad off before starting it. Also an application of rad seal stops it leaking for a while if needed... Until I find time to go through the other engine and decide what to do long term.

 

[Flatland Fox]

I think you cannot use a head designed for a different bore but, probably, many other items are interchangeable. If you have a cracked block and It does not leak and works fine, you have got two options: be a wise man, do nothing and enjoy your tractor and luck, or the Flatlandfox option which basically means to disassemble the whole engine, strip the block, see if it is interchangeable with your spare block (I will try to search that), and repair the block properly at a modern facility with experience in cast iron welding. Option B will lead you sooner or later to an strong feeling that you are playing the fool, but don ´t ask your wife for confirmation, run the full gauntlet and you will be extremely proud of you and your tractor as soon as it comes to life.

 

[User27]

Frankly amazing that it runs and the oil and water aren't completely mixed with this internal crack:

 

[User27]

Another picture from the top end rebuild last year, can't immediately see why there would be any issue fitting this head to a block with a slightly larger bore.

Once I get the new (well 70yr old, but new to me) block bare I'll measure them. The pistons in my existing TVO block look a lot better than the ones in the 25d at first glance; haven't seen replacement pistons available so I assume they are normally reusable with new rings and liners.

Looking forward to the next installment of your rebuild series of pictures.

 

[Flatland Fox]

That this crack is not mixing oil with water should be considered a solid proof of the existence of God Allmighty!
The repair needed needs to remove the linings, welding the bores, machining them and resurface/ machining the upper surface.
The VAK had 3,5 inch bores and the 25 D had the same measure. Check this: VAK 1A (1945-1947) | David Brown Tractors
I have the service manuals of both. Hope they are helpful.

 

[Flatland Fox]

You might also finthese suppliers useful:

Home | David Brown Parts Ltd

Home page - Worldwide Parts for David Brown Tractors

www.davidbrownparts.com

 

[Flatland Fox]

And this junkyard also had lots of spare parts, some of them extremely hard to fin:

Tractor Supplies | New and Used Tractor Parts | 1920's - 1980's - David Brown

Richard Pocock, suppliers of New and Used Tractor Parts for Vintage and Classic Tractors built 1920'2 to 1980's British and American - Hard to find parts - Tractor Breaking

www.pocock-tractorsupplies.co.uk

 

[Flatland Fox]

Sorry about the typos. The text corrector takes its own decisions.

 

[User27]

All that information is appreciated and will hopefully help others in future also.

You might be able to see a printed copy of the 25c manual in the background of my last picture there; most useful. I also have the 4 cylinder TVO engine spare parts catalogue which has excellent exploded diagrams:

I see Mr Pocock has a TVO tank with the same issue as my one up for £150+VAT and hundreds of pounds for cracked blocks; good to know these things are available in a pinch but I'm afraid I can't stomach the cost so I have no personal experience with them.

Peter at David Brown Parts has helped me out with a few bits; I have found them to be towards the expensive side for some items but I found Peter to be exceptionally knowledgeable and he has talked me through exactly what I need just for the asking so well worth the money imho.

 

[Flatland Fox]

This is the hydraulics control already cleaned.

The lever had been repaired with rather rough which required some attention. The whole module was adjusted and primed. Here it is together with the support for the rear light switch.

 

[User27]

This is the hydraulics control already cleaned.

View attachment 22308

The lever had been repaired with rather rough which required some attention. The whole module was adjusted and primed. Here it is together with the support for the rear light switch.

View attachment 22311

Looking good.

Will you be doing a full service on the brakes with new liners etc? Or are they working ok on your machine?

 

[Flatland Fox]

I bought a set of new liners with rivets together with many other items before brexit in case I might need them, but now that I can get the engine running happily, I see that the brakes work fine, so I think that I will do no more than greasing the related linkage. Opening the brake chamber requires the removal of the huge axle casting at each side. Seems like looking for trouble in order to repair something that is working properly.

 

[User27]

Best information I have found beyond the manual is this below, it does indeed look like a heavy lump that you don't need to touch if they are working.

David Brown Cropmaster brake upgrade - David Brown Tractor Forum

Presumably shade tree mechanics locate strong overhead shade tree branches for such tasks. Can't say I'm looking forward to the task any.

 

[Flatland Fox]

Well, here I am again. After a full month holiday in a greek island I am back in business.
Just some hours before leaving for Greece, I bought this Deutz D 4005:

As I was loading it on a platform, Pepe convinced me to take it to his shop, so that he could start working in it. I was somewhat reluctant, but Pepe is a great chap and a great tractor mechanic and maybe it was not a bad idea.

I was wrong.

As I arrived home, I visited Pepe and my cherished Deutz looked like this:

Last weekend I have been able to put the oil pan in place, a new rear crankshaft bearing and seal and the extremely heavy flywheel. The engine (air cooled, no radiator, I love it!) looked as new. The clutch had one worn disc and I changed the lining, it also had two rocker springs broken but I was able to replace them with self made springs. The gear box was originally blocked but after one month filled with diesel fuel, now it runs freely. Enough of a teaser, this rebuild will be the subject of another blog sometime!