Hi, Perkinsengineer.
Good welders can do some pretty remarkable things these days with modern technology and techniques. I don't claim to be a top quality welder but I'd have a shot at repairing that bottom tank, either with carefully selected scraps of cast iron welded together to patch the hole or by making up a piece of mild steel to the shape and welding that in. The problem with the mild steel approach might be different expansion rates but I'd 'havago'.

Some 'judicious preheating, peening and grinding' would be in order, whichever way was chosen.

The cast pieces would probably give the more 'authentic' finish.

Just my 0.02.

Just my 0.02.

I have a No. 12 grader with some shoddy welding repairs on the transmission and high-low shifting levers.  Are these levers cast iron or cast steel?
Should they be brazed or otherwise?  If they are to be brazed; will they hold up in use?

Cat D 318 heads must be some of the toughest around as far as cracking, I have not heard of even one. If you have bubbles in the radiator 98% chance it is pre combustion chambers. They can rust out and leak combustion gas, or the washer seals under them need replacing, or worst case the seat in the head needs dressing. I have had poor seats seal with a real copper washer seal, when the steel copper painted ones failed.


The age of parts and the way most of the engines have had mostly other than pure demineralized water run in them, a rodding out of the core does wonders. It is a job most are able to do themselves. I have never had a broken cap screw on the cast iron parts that would not come by welding a nut on the broken pieces. Some I have welded 5 or 6 nuts on before it came, but it came without destroying the threads. And I don't claim to be a great welder.

I have started the rodding with pieces of old school gas welding rods. Gently tapping one in a ways, backing out, a shot of air, and more tapping it down. Then start a second rod by the first after you get the first all the way through. Then finish with a piece of aluminum flat stock I found a hardware store. I have done 4 without causing any new leaks. One had a leak that I had used gasket group on a stick pocked hole. I closed that tube with solder top and bottom. It is alway a bit of a worry with old radiators, but have had good results.

But start as Des said by cleaning the outside of the core very well, and make sure the belt is somewhat tight. As well as thermostats do fail, but make sure the old one is bad. As the last new ones out of a Cat box I saw for a 318 engine said MADE IN CHINA on them.

trainzkid88 wrote:

it was common for the drain bungs to be removed from the steering clutch compartments to allow any crap to drain away if working in water/mud it also allows wasps and other creatures in
 

I think you mean the other way around. The plugs work as intended to keep the mud and water from entering but mostly they are removed as the bevel gear shaft seals or the final drive seals weep oil or the seals on the access covers and control shafts let water in. If you are working in mud or water deep enough to enter the steering clutches through the plug holes then you should put them back in or put them back in but drill a hole in them and put a split pin in the hole.

Also you mention welding and cutting to fit pre-heaters, intake manifolds on these are cast iron. I would not like to try welding anything to them.

UNS is a rolled thread at 8TPI. At the power plant where I work we have hundreds of pipe flanges bolted together using UNS threaded bolts. Allowed the company building the plant to save money by using UNS studs as they can use the same thread rolling dies for all sizes of threads.

Course thread on studs has nothing to do with they way they lock, it is to do with the material the parent metal is made of. Studs have a course thread on one end for the same reason that you will rarely see a fine thread screwed in to a cast iron or alloy part. The thread is also usually longer than the fine end to allow more contact area between the softer cast iron and the bolt or stud.
I learnt this at Trade school (TAFE) both in my main trade as a fitter/machinist and as my secondary trade as a mechanic. I am also a fully qualified welder with pressure welding qualifications and a fully qualified plumber.

cast iron /cast steel the best method is bronze welding with a oxy-torch soak the part is water based degreaser for a day or 2 rinse well, vee out the joint and bronze it up not it must be preheated first so "borrow" the oven and heat it to around 150 to 200 deg celcius for at least a hour before trying to weld. it will also need slow cooling so a steel bucket or a old drum filled with dry sand dig suitable hole and light a fire in hole to preheat the hole this can be burning while you weld. bury the part in the heated sand and let cool for a couple of days
grind and file the weld so its only just proud of the surface and hose no sharp edges it should last for decades.

the preheat helps prevent cracking and also help dry and pull impurities from the metal. the slow cooling prevent post cracking.

you can use flux coated or plain rods with flux flux coated are easier to work with available in a handy pack for those small jobs

Hello all,
I have a cracked flange on a D4 pony motor, P/N 5B5105, and I was curious what the best repair method would be. I've seen some people say that it's cast iron, but it looks more like a steel to me so welding might be better than brazing. What are your thoughts here?
 
Thanks, 
Mike

Really appreciate all the advice and suggestions. Thank you to all who have chipped in! Here is where things stand:

As to whether cast iron or steel, I have had experienced folks express confident opinions both ways. When I do a bit of grinding, I will do the grinder spark test. Regardless, it was poorly welded and re-welding is still a long shot option.

At this point I am anticipating trying to seal the interior and the exterior. This will involve cleaning the interior, using repeated cycles of heat and brake cleaner, sweating out as much oil as possible, roughing up the surface, and, if I can get my hands on it, using Glyptal 1201 Red Paint to seal the crack. With the exterior, I will grind down the weld to create a clean surface and, again if I can get my hands on some, seal it with Permatex Spray Sealant Leak Repair.

The challenge is that neither product is available locally. In fact, the Permatex Spray Sealant is not sold in Canada. So working to source. The alternative exterior treatment would be JBWeld with fiberglass. Or at least that is my latest exterior option. But I am working on seeing if I can find someone going between Alaska and the states to pick up a couple of cans, passing them along to me (for appropriate consideration) when passing through Whitehorse on the Alcan highway.

I have at least a couple of weeks before my access road will be dry enough to do any repair work. And I am also waiting on the re-glazing to be completed. as well as for filters and etc. from Cat to do a general oil and filter maintenance.

when dad worked for bonel bros they had the agency for belerus tractors which had one slight problem you couldnt keep oil in the sump due to porous castings so the fix was to pull the sump off and clean it thoroughly and coat it with red lead paint once cured they would refit with a new gasket and problem solvered. may be that is the solution for you.

another method would be to clean thouroghly and flow solder over the area inside that would seal the casting.

cast is hard to arc weld especially old cast as it is unknown composition and the rod used depends highly on the type of cast iron or cast steel. that's why bronze welding with a oxy set is better for this kind of work its lower temp and doesnt shrink the same plus less localised heating as its slower the heat spreads more.

a tip no matter what you choose is pre heat the whole housing before welding and the best way to do that at home is to build a fire it a pit in the ground, let it go to coals and place the bare housing in it burying it in the coals add fresh timber or coals to keep the fire going slowly. if you have access to a wrap around induction heater well you could use that not many shops would have one though. after welding bury it in the hot coals again to slow the cooling. its why blacksmiths shops had dirt or sand floors so they could bury things in the floor to control the cooling and dirt wont burn.

heating will also help remove the oil residue.

I repaired a crack in the water jacket of an old diesel engine with a product called locknstich. Basically it is a non welding process where holes are drilled and tapped and a screw is threaded into the hole and broke off. Each hole interlocks with the previous screw creating a seal for the length of the crack tying it into solid material at each end of the crack. Look on the internet and watch some of the videos of people using the product. It is something a guy with a drill and a tap can do without the hassle of attempting to weld cast iron. it sells as a kit which includes everything you need to make the repair. In a no stress location I think it is easier than trying to weld or braze a crack. bboaz

Hello All
The ball joints on my 944's bell crank are completely worn out. There is up to 1/2" of play in one and 3/8" play in the other. There are no available spares from Cat. To make matters worse it has been repaired before but very poorly. It has been welded before and test drilling confirms it is not cast iron. I am thinking of using a ball joint rod end (like this one) and welding a bolt in the hole the old ball joint was in. The old ball joint had a 15/16" UNF thread so if I go to a 1" bolt it should be as strong as the old one. The amount this machine will be used I doubt the rod end will come loose. Does anyone have a better idea or know where I can source weld in tapered ball joints?

Also the ball joint tapers at the wheel end of the tie rods have been loose for some time so the holes are elongated. The actual tapered shaft on the ball joints are still fine. I want to fill the holes with weld and drill them out and ream a taper. I think the taper is 10:1 or 5.71 degrees, can anyone confirm the taper Cat uses?

Regards

Phil

I would suggest you use expoxy. I have done a bit gas welding over the years,some times it looks like I know what I am doing. Other times you know I cannot. My guess looking at your pictures is not clean enough and/or enough flux.

Gas welding is a lost art with all the cheap migs to do light sheet metal.So I don't want to discourage you but cast iron that has to hold liquid is not a good starting place.

Pulling is the wild card. I had one on the grader when I bought it that had come loose and messed up both spindle and hub so I just had to be able to press the new/used hub back on the new/used spindle. That was a front spindle so no brakes behind it.

Then I jacked up the other side and could hear something loose and scraping around in there when I rolled it over. So it had to come off to even diagnose the problem. That’s when I borrowed the t bar puller. I could have welded up one once I saw what it took to get one off. The forcing screw was about 1 or 1-1/8” fine thread and as I remember the threaded holes in the hub for pulling are 5/8 coarse. I just grabbed some grade 5 nuts and all thread and it worked just fine.

If I had to build one, I would buy about 16 - 18” of grade 8 all thread and two nuts to fit. Then a piece of heavy 2” square tubing for the cross bar and the spacer. Drill two holes near the ends of the cross bar spaced apart the same distance as the holes in the cast hub. Drill another one in the center between the two for the forcing screw. Cut another piece of the square tubing to stand the braces Opoff about the same distance above the crossbar as the two small holes are apart. Then you can use 4 pieces of flat iron say 1/4x2” to brace from the nut to the ends of the cross bar.

So this thing would look like a large triangle split in equal smaller triangles by a vertical section of the same square tube with the nut at the top of the
and the 4 braces (two to each end) angling down to the ends of the crossbar.

Note, I drew this with the nut under the bottom of the cross tubing but realized later that though this would reduce the need for really good welding to attach the nut to the top of the standoff tube, it might just crush the cross ways piece of tubing.

I did some browsing on McMasterCarr and they have both 1 and 1-1/8” fine thread grade 8 in 3' sticks for about $60 and nuts are about $12 each so you would have maybe $150 in materials plus welding if you couldn’t do it yourself. I usually build this type thing for a specific job but later it gets modified for other uses by drilling holes on different spacing

I have had experience with cracks on 1926 ALF fire truck engine cylinder jugs, in an area near a valve seat, and water jackets. It was stitch weld repaired, a very good but tedious job. No heat, or trying to weld old impurer metal castings. I have also used J B Weld, which is a 2 part epoxy mix on the same castings with success. I had a crack in the oil pan on a D-2, preheating and welding never worked. Good luck, I hate cracks in cast iron.

Hi, Folks.
Here are a couple of links to videos about the Lock-n-Stitch method of cast iron crack repair - might be helpful to somebody.

And a couple of videos about welding cast iron with Muggy electrodes:

Just my 0.02