Caterpillar 12 grader engine is dead - please help?

[Entropy1]

The problem is that I have no idea why this thing was taken out of service. I might just bite the bullet and yank the whole engine - then fully disassemble. The previous owner yanked the injectors - presumably to soak the cylinders - and gave up on it. The college gave up on it also. Some fasteners were removed - in locations that suggest someone was getting ready to pull the engine.

Piston/cylinder kits are about 300 bucks per hole (x6). A complete gasket set will be about 600 bucks. The cylinder head is an unknown. I'd probably take it in for servicing (seats & guides, or a valve job at the least) - the head could be 500 to 1500. It's been a while since I sent a crank out for turning. I think it needs to go to by truck to Portland. Crap. . . .

 

[Entropy1]

https://www.amazon.com/dp/B0BL7LYR9Y

On a happy note - the new borescope camera is really nice. I felt it was quite inexpensive - considering the quality. It takes pictures and video.

 

[OzDozer]

Make up a mix of 50% diesel and 50% ATF, pour half a cupful of the mixture into each precom chamber and leave it for a week, and it will bar over.
You could try fitting the camera down through the precom chambers, but all you're going to see is rusty cylinder walls, anyway.
WD-40 is pretty useless for freeing up stuck engines, I've heard guys say the stuff only encourages more corrosion! The ATF will clean up the rust, and the diesel will lubricate the bore and rings.
You won't need new cylinders and pistons and rings, you're indulging in overkill thinking. These things were built to last 100 years.

 

[skyking1]

What he said and what I said in the beginning. Get a dose of oil in there and just take your time. Give it that week and then don't attack it with the bar and expect instant gratification.

 

[Entropy1]

I will do the 50/50 diesel/transmission mix. I can wait a week for them to soak.

Question - which direction does the engine normally turn (standing behind the grader - looking at the water pump end of the engine)?

 

[Entropy1]

Hypothetical Question:
Assume for the moment that my attempts to unstick the engine with 50/50 diesel/transmission mix are unsuccessful. Would there be any advantage to pull the head (without pulling the engine) and attempt to further clean the cylinders by hand? I'm worried the part that's stuck is between the piston and cylinder, and not necessarily the cylinder above the piston.

Further Hypothetical Question:
Let's assume the engine is really stuck. Is it feasible to pull and disassemble it, then lightly hone the cylinders, clean up the pistons, and install new rings? The obvious variable would be how deep the corrosion damage is in the cylinder walls. I don't mind doing the labor - I just don't like to spend money unless I have too. . . . If I'm that far into it - at which point do I purchase cylinder kits?

 

[Delmer]

The school was going to take the engine out because that's what they do. Doesn't matter if it ran like a top, they'd pull the engine apart and put it back together, every semester.

You don't have to wait to try to turn it over. Put a socket on the crankshaft, or pull the starter and pry on the ring gear (don't pound on the ring! or use a big bar, just a little leverage) I don't see any rust in those pictures, I'd expect rust if there was water in there, even if the engine was still free. Look at the curve of the fan blade to see which way the engine turns or the ring gear, the bevel is on the back side of the gear as the starter turns it. so the forward side of the gear as the engine turns.

 

[Entropy1]

What is the direction of airflow? Does the fan pull air through the radiator, or push it? This might seem trivial, but I'm not quite sure that the fan is installed correctly either.

The exhaust gaskets are rotated 90 degrees - implying they pulled the exhaust manifold, then quickly slapped it back on (below pic).
Fasteners connecting the water neck to the radiator are missing.
Fasteners connecting the air inlet manifold to the engine are missing.
Fasteners that hold the small exhaust piping for the pony motor are missing.
Fasteners holding the cover containing the fuel pressure gauge are missing (all but one)
The fan belt is currently not around the crankshaft pulley.
The injectors are missing.
The fasteners that hold the engine cover (hood) are missing.
Also - not quite visible in the second picture, there are electrical wires (below the gas-fill cap, near the top of the chassis frame-rail) that are burnt badly (electrical fire - the fire damage was limited to just the wires). It looks like the wires rubbed through the insulation and shorted against the frame. The circuit was obviously not properly fused. The wiring terminals to the pony motor starter & magneto have been disconnected. It would appear that someone was also trying to troubleshoot the electrical. The easy fix for the electrical will be to simply replace the wiring. Perhaps the wiring fault initially took out the machine, and frustrated by the electrical fault, the guy walked away from the machine and forgot to cover the exhaust? Who knows. . . .

I really wish my manuals were here. I hate jumping into a partially disassembled project.

I suppose the good news is that the college never touched it - implying that everything I'm seeing was done by the previous owner (who donated it to the college). It's too bad I can't contact the guy. I'd love to ask him about the history of the machine.

 

[skyking1]

It is far more simple than you are posting here.
1) bar it over. if it moves go to
2) put the parts back on. get injectors. freshen up the fuel.
3) get pony going. fix wiriing as needed, There is very little wiring so don't sweat that either. Field wire generator wire and that is it for the generator.
4) get it rolling with the pony.
add fuel. chunka chunka chunka.

 

[Entropy1]

We shall see. I hope you are right.

I'll tinker with it this weekend. I'll also post pictures of the electrical fire damage.

 

[56wrench]

Those are easy to pull the exhaust manifold off to check which cylinder drank the water. Then you can narrow it down.

 

[Entropy1]

Question - how do I find my engine serial number prefix? The serial number on the engine is 8T14140.

Note: I'm being asked if it's a 3V, 5V, 6V - there is no 8T option. . . ?

 

[Nige]

Question - how do I find my engine serial number prefix? The serial number on the engine is 8T14140.

The engine S/N prefix is 8T. More correctly 08T in today's online information system, but it matters not because no information for a machine that old will exist online anyway.

Your machine dates from an era when the engine installed a machine carried the same Serial Number as the machine itself. Therefore provided the engine is the original then the answer to the question you are being asked is 8T and even if you can't find a Serial Number on the machine anywhere the chances are quite good that 8T14180 is also your machine S/No

From my Serial Number book the #12 grader was manufactured under the following seven different Serial Number prefixes in the US along with first year of production. My information may be not be 100% complete but it's the best I have.
9K - 1938, 6M - 1939, 7T/8T - 1947, 80C - 1955, 70D/71D - 1957.

Regarding the other S/N prefixes you were being asked about. 3V is a D318 genset engine, 5V is a D318 industrial engine, & 6V is a D318 marine engine.

 

[Entropy1]

I just got off the phone with a parts supplier that sells D318 engine rebuild parts (cylinder kits, bearing, valves, seals, etc) . He told me 8T14140 is an invalid part number for a CAT 12 grader. Maybe I should've said 08T.

 

[Nige]

He told me 8T14140 is an invalid part number for a CAT 12 grader.

See this quote from Ozdozer's post on Page 1. He even gave you the year it was built so it's a genuine number. Your parts man is talking out of his rear end I feel. I'd be interested to hear what others think....

8T14140 was built in 1954 (1954 production ran from 8T13818 to 8T15522) and there will be a range of dismantled Cat graders and new aftermarket parts available for it.

I'd suggest to take Ozdozer's advice and get hold of a parts manual before you start trying to buy parts. Then you can phone up parts people and tell them what Part Number(s) you are looking for instead of blundering around like a blind man in a darkened room. My 2c. YMMV.

 

[Entropy1]

I did take Ozdozer's advice. The reason I was asking about the prefix number of my engine was because I was purchasing manuals, and I wasn't sure which manuals to purchase (aka, 3V, 5V, or 6V, or ???) - so I simply purchased an assortment - they were all pretty cheap. The following manuals are ordered (paper copies):

1952 Diesel No 12 Motor Grader Parts Catalog Caterpillar SN 8T1-Up
Caterpillar D6 Dozer No. 12 Grader 4 1/2" 6 CYL D318 Engine Service Manual
Caterpillar Vintage No. 12 Motor Grader Servicemen's Reference Book
Caterpillar D318 OPERATION & MAINTENANCE MANUAL ENGINE BOOK GUIDE sn 45B1+
Caterpillar D318 ENGINE PARTS CATALOG MANUAL SN 5V5001-UP
Caterpillar D318 ENGINE PARTS CATALOG MANUAL 3V5001-UP
If these don't get me the information I need, I'll purchase some more. . .

I also wasn't questioning Odozer's previous post - regarding his decoding of the year my Grader (I took what he said as factual). Again, the reason I called the parts-shop was to see if they could tell me my engine prefix (it would be in their interest to do so - presumably if they desired to sell me any D318 engine parts). I wasn't expecting him to tell me my Grader has an invalid serial number.

I still haven't tried to bar over my engine. I'm going to read over the manuals first. If I do end up pulling the engine and disassembling, the first step will be to check iron for cracks (to make sure it's even rebuildable). Not purcahsing any parts yet.

 

[Nige]

I wasn't expecting him to tell me my Grader has an invalid serial number.

That gives you a good clue as to how much to trust their advice in that case...........

 

[Bluox]

The engine parts are in the machine parts book.
That engine don't have an injector it has a nozzle, holder and bonnet cap that are missing.
Bad Bob

 

[OzDozer]

8T14140 is the grader serial number, not a Cat part number, so the parts man isn't exactly the sharpest tool in the box. You will find very little online information in Cat current records as regards a machine this old, it is 100% antique to Cat, and they long ago discarded their "no orphans" parts policy (it was 1955, IIRC).
The grader was built in the era of printed manuals and books, and they're still your best reference.

The current engine serial number prefix, which has been divided into model number prefix and engine arrangement number, does not apply to your machine, as this prefix/arrangement number system was not introduced until around 1972-73.
However, Cat did start to use engine prefix numbers for industrial, marine and genset engines in the late 1940's. Those engine books you bought will be useful, but they're not 100% accurate, as they apply to the various engine applications where some components have been changed or added for the application.

The engine model number for your grader (D318) is still a good reference start for engine parts. However, it will take a good Cat parts man to drill down into "previous models" records to try and find any reference to the engine.
In the early days of Cat online parts information, the parts interpreters had a separate reference source for older products. That reference may not even exist today, in Cats online parts record system.
However, all aftermarket suppliers will immediately recognise "D318" for a start point for looking up engine parts.

 

[Nige]

In the early days of Cat online parts information, the parts interpreters had a separate reference source for older products. That reference may not even exist today, in Cats online parts record system.

I can generally find parts information for older equipment in the online resource, but nothing going this far back in time. As Oz says, this is a case where the (correct) paper Parts Manual is pretty much the only good resource available.

Another thing. Many of the Part Numbers in your paper Parts Manuals will be written in an older format to the one used today. You might well come across a Part Number such as 6N968, 2P726 or 6V44. The newer format of writing such numbers is always 6 characters. 1 number, 1 letter, then 4 numbers.
So in today's system 6N968 becomes 6N0968, 2P726 becomes 2P0726, and 6V44 becomes 6V0044.