Well now that Rallies are alive again after a 2 year break, I decided to get David out and give him a bath. He looked like he had been the target at a shit throwing contest with bird poo, spiders and webs and dust an inch thick. Drove him down the driveway and hit him up with the truck wash and gave him a quick lick. Then it happened! Conked out and I just knew what the problem was, once again. Dirt/rust in the fuel tank. Over time I have done all sorts of things to this tank to cure the problem. This tank is a 2 piece tank for petrol/kero. The petrol side is not too bad but is a small tank compared to the kero side which is the one I mainly use especially if going on a trek.
So from blowing compressed air through the tanks to trying to vacuum it out even using a fuel tank sealing system that is supposed to convert rust, prime the metal then coat and protect it. Now the biggest problem is the kero tank has a long tube welded in place from original to act as a splash guard and fuel not blow back up through the vent in the cap. This is what stops me from gaining good access to the inside. So today was judgement day and just as I was about to start on the job of cleaning it out again and see what was going on I got a call from Oliver1950 who made a brilliant suggestion to install a short riser onto the copper fuel line that goes into that tank.
So once I drained the fuel out and put a light over the hole I could see a fair amount of dirt plus a nice shiny silver coating on the bottom of the tank plus a bit of it on the down tube. When I used the sealant kit I poured more than enough of the sealant into the tank and spent the rest of the morning rotating the tank to ensure full coverage of the inside. Only problem is you cannot get it to coat that bloody tube on the outter side of it and this is where I think the crap is comming from.
So back to using the vacuum to remove as much as I could see and then took the short fuel line that runs from one side of the double sided tap to the tank. Years ago I rolled up some stainless steel 'termiguard' mesh like a ciggy and shoved it down into the tube to act like a filter and stop it blocking the tap assembly or getting to the carby. So now with the riser in place I lost a bit of fuel capacity but hopefully the crap will hang around the bottom and not block the riser or fuel supply.
First pic is of David in all his splendor beaming out in the sunshine. Pic 2 you can see my old inline filter no longer in play and the new riser sweated into place so it doesn't fall off inside the tank. Pic 3 is my high pressure vacuum cleaner. Like me it is simple but effective. Pic 4 shows that bloody tube inside the tank and how clean it appears and the silver sealant.. Pic 5 shows as best I can an overview of the fuel tank opening.
For those who need to know the sealant kit is from KLB in W.A. and is a 3 stage kit and comes in various sizes for different size fuel tanks.
Tomorrow I am double checking the repair by having him running again for a while but also testing the electrics from generator to regular. I have trouble getting my head around the Amp gauge on the dash as it is a 60A gauge, a generator will not put 60A out on a good day on these old girls and they should be a 30A at the most to my way of non-thinking.

I seem to recall this has been a issue pretty much for as long as you've had the tractor

Is there a reason that the tank cant be cut open, cleaned out and the welded back up ?

Once I have done this it is the end of these type of issues for me

Some other things that can be done are fitting a hose inside the tank and a simple inline plastic filter, drill lots of extra holes in the filter

The number one problem with blockages forming like this is flow rate, the faster the flow of liquid the sediment moves in and blocks the pickup

By drilling extra holes in a filter the flow is dropped dramatically and flow of sediment is also reduced

Of the pickup diameter is doubled the flow rate is a 1/4, so a dozen holes is nearly a 50th of the flow rate


Paul

Cobba

Your riser system is sort of Ok but it reduces your capacity as you say and can still get blocked by semi-floating crap or even when you go over rough ground and stir up the rust flakes.

A man of your dexterity could make one of these up in 15 minutes. No matter how much crap was wandering about in the tank you will never stop and hardly reduces your capacity at all.

All aircraft have them and they can be bought at any aircraft supply place or aircraft wrecker pretty cheap but I have made maybe a dozen of them over the years by soldering a 2 inch length of copper pipe onto the tank fitting then drilling as many tiny holes as I can in the pipe. A two inch pipe with lots of holes will flow enough for a big V8 engine. If you have it available roll up a bit of brass/copper or stainless fine mesh to create the tube.




www.ebay.com.au/itm/403485423273?hash=it...9:g:EiMAAOSwQM1iEPIX

www.ebay.com.au/itm/164695160770?hash=it...2:g:wbAAAOSwLf9gIxZx

www.ebay.com.au/itm/175159725118?hash=it...e:g:5Y8AAOSwmodiC52N

Here is a Holden tank strainer which you can solder or if it is alloy epoxy putty on top of the inlet fitting.

www.ebay.com.au/itm/284278559344?hash=it...ZfuXl&frcectupt=true

And a ready made tractor one.

www.ebay.com.au/itm/402073956335?hash=it...7Ctkp%3ABFBM-LqL8q1g

Hi Paul, yes it has been an ongoing issue and after the sealing treatment that was suppose to be the end of it all but sadly has not. I have always avoided cutting the arse out of the tank and yes it is still an option but if avoidable I will avoid it.

Lang, thanks for the extra info. I have been running the engine today and have had a couple of stops and I have also been able to remove a tiny bit more of the sediment at the bottom. I just might drain the tank again and modify the copper tube I ahve already sweated into the fuel line and rill some small holes in the wall. I do have some very small drill bits but maybe too small for a 3/8" chuck but I have wrapped the shank with masking tape in the past to make it large enough for the jaws to grip. More to play with tomorrow.

After looking at those filters I think my one was way too fine and was blocking up. Now to try and work out what would be the best size drill bit to use as I was thinking 1mm but now a bit bigger.
Any suggestions as to size please?

I recon 2 or 2.5 might be the go.

Thanks for the reply Lang, those sizes are far more workable with a 3/8" chuck in the bench drill. I have drained the tank again and about to remove the fuel line, again. Will see how it goes later in the day.

When you think about it you are just trying to stop major items getting through which will block the line. The normal fuel filter takes care of the fine stuff. You will note how coarse the screens are on most of those aircraft ones.

Fine screens in the tank itself are a pain in the a.... I can remember laying under an old Range Rover on the side of the road, pulling out the tank line and internal filter, getting covered in fuel and stabbing a screw driver through the screen to get the damn thing back on the road.

Lang

Thanks Lang,
In todays episode I removed the fuel line to drill a series of 2mm holes along it and crimp the end, Easier said then done with it sweated in place and I made an ugly job of it but it will not be seen when fitted. Then because the tank was empty again and I saw more silt sitting there so out with the vacuum again to clean it up. Fitted the fuel line back in and tried it and away we went for a while and stopped again. I now had a new suspect, the fuel tap. I noticed a small amount of silt in the glass bowl so while it was off I had a look up where it seals against the tap body. A cork gasket seals the glass bowl and it was breaking down. Now I bought this gasket a few years back and when it arrived I noticed it was not a pure cork gasket, it had black neophrine looking stuff mixed in with it. So I found some pure cork gasket sheeting and made a new gasket with my circle gasket maker, simple but effective. So I cleaned all inside and removed my home made gauze from the top of the glass bowl and it was fairly good in that area.
This tap has 2 inlets and one outlet as David is a TVO engine (petrol/kero or Tractor Vapourising Oil). The tap handle is a tricky bugger and the screw to tighten it up is worn and only just does the job of stopping fuel leaking past that gasket but it is still usable. So after it was all cleaned out and my gauze fitted and new gasket I put it all back together again. I am getting better at doing this job now but don't get much joy from doing it.

some more pics. Also while playing with David I had a suspicion about the charging system. I am still running the old Lucas 12v generator system becasue I like it that way. But lately when I used the multimeter on it I was getting confusing readings and yes I am aware this is positive earth. Something that when I tested did not read as it should was the continuity of the main "D" cable (battery) back to the regulator. So I unwrapped the tape and cut off the old terminal and crimped a new one on and now it passed the test so when running the engine to see how long the engine would run I was testing the generator first by disconnecting the leads at the generator and bridging them then reading the output at idle which was around 12.4v. Put the leads back on and then tested the reading at the battery. Battery held 12.45v just sitting there but when the engine running it was constantly jumping from 13.5v - 15.8v mostly and this is from above idle to about 3/4 throttle. On maximum throttle the meter was blanking out on the 20v scale which meant the voltage was jumping between 15.4v - 19.8v+ but then would settle down to normal after a while. I think the regulator might be a little shitty having to work again after a 2 year holiday of doing nothing.