I have an older D6N. It is not making full power. I know I have rust in the fuel tank issue. I am not using it much now. I have been blowing back trough the fuel pickup line occasionally to keep her going. The tank has baffles. The right baffle blocks access to the pickup from the fuel cap. I would really like all the advice I can.get before I dive in to this. How to remove the tank, how to clean it and how to treat it or is replacement the best op? Also, I have and older topcon machine controll system for it . Think it is time to sell. Will make another post about that. Any advice appreciated.
Attached the procedure for removing the fuel tank. Re-installation procedure is the reverse of removal. If you are going to the trouble of removing the tank then generally the procedure to gain access to the inside is to cut a square/rectangular hole somewhere convenient (bearing in mind the location of the internal baffles) to permit you to "access all areas" of the inside of the tank. Cutting the hole with a plasma torch would likely produce a plate that could be welded back into the tank relatively easily. Once the hole has been cut the tank can be vapour, sand, or shot-blasted from the inside per your personal preference. At the end the section of plate gets welded back again.
What is "vapour blasting" - Thnaks again. Cool , I found one pic on the web of D6 tank . He cut and bolted a plate back. I am going to have a look at the tank and baffles agian. thinking out loud. Maybe cut without removing? Install a port that will allow access later. Clean / descale tank as much as is accesable through one port. I can reach, I think, the middle to the bottom of the tank. But left 1/3 and right 1/3 of tank is blocked by baffles . Wounder If I can find a flanged port that could be wleded on after cutting hole? Maybe I should scope the tank before just to see how thing look?
Any thoughts on this access port ? https://fueltankparts.com/products/8od-x-6id-bolt-in-tank-clean-out-access-plate
I was under the impression that you had already done that and was the basis of your comment regarding “rust in the fuel tank”. If you have not had a non-invasive look inside the tank first that should be your first step IMHO. You need to know exactly what you are dealing with before you can make a decision regarding how best to deal with it. Vapour blasting is a surface cleaning and refinishing process that propels a mixture of water, compressed air, and fine abrasive media (like glass beads) onto a part. Also known as wet blasting or aqua blasting, it is widely used to remove dirt, grease, oxidation, and old coatings without damaging the underlying substrate.
I have inpected the tank with a flashlight looking in. removing petcocks, reaching in with my hand. But I need to look harder now and come up with a plan. I only generally know what I am dealing with and your help is much appreciated. Lots to consider: take her to my shop? Remove Tank? Inspection hole, weld back or install accesable port. Baffle location . Will I need two ports because of baffles . No mater what a I cut a hole with, it is going to throw debris all over the inside tank inside, I think. Got to be rinsed, I guess, after. What will I rinse with ? Is this practicle without removing the tank?
You are correct that cutting the access hole will result in additional debris inside the tank. This is why such a procedure is normally performed with the tank removed so that it can be turned upside down or similar so that debris can be flushed out.
I'd have to see the tank and do a good inspection with a boroscope but if it needed a hole cut I'd try to do it with a hole saw. You could weld the plug back in or weld in a flanged bung fitting you could thread a pipe plug into (like on a slip tank). Then you'd have a simple way to inspect the tank if you had more issues. You wouldn't be blasting sparks and slag everywhere. Other option is a cut off disk in an angle grinder but that would still throw some sparks all over.
Nobody mentioned “boiling” it out with Muriatic acid, yet. Works pretty good. 5 gallons should do the trick. Slosh it around and and rinse with hot water from your water heater if you don’t have a Hotsy.
Reading this thread brought back memories of one of my 68A D8H tractors with a similar problem. Attacked the fuel tank with oxy torch with fuel cap removed and hoped for the best. Cut a crude hole in the back of it halfway up so get access with a bunch of rags and a swill out with diesel back in the day when fuel was cheap. It did work and I welded a big plate back over the whole area praying it wouldn’t leak. It worked fine to be fair,but it was cowboy violence to an innocent D8 that certainly couldn’t be done these days with all the fuel injection systems being so critical.