"You put your hand over the open injector hole!?" "You know what have to say about that"

"Rome wrote:

"You put your hand over the open injector hole!?" "You know what have to say about that"

Not the hole on the injector, but where the injector goes in the precup. I felt like I could put a finger over the end of the injector though. Not MY finger, of course, but the finger if someone else. Preferably a dead someone else, but I don't carry around dead bodies. Not after that last incident.

"That's good to hear"

What did the injector spray pattern look like? They should “crack” at over 1450 psi (maybe 1750....can’t remember for sure) so while I’m not sure that would cut through a blue towel, it should make a nice cone shaped fine spray.

Well, I went out to the tractor today and I'm not sure where I'm at. Let me explain.

In the last episode, I removed, inspected and reinstalled the transfer pump and I still only had barely 10 PSI at the gauge port.

Today, I started by removing the injectors. (Hint, if the nuts are tight, try a hammer and punch and smack down on the edges of the nuts.) Once they were all out, I fired up the pony and when I closed the comp release, we had compression but how much, I don't know. I could almost hold a rubber plug over the hole and I'm not a big guy. So maybe compression is low.

But in the meantime, I noticed that there was almost zero fuel coming out of the fuel line ports on the pumps. I hooked up a line and injector and had no spray, whereas last time I did have spray. I also noticed that there was only 6 PSI at the gauge port. Pulled the filters and while cranking, there was fuel coming into the housing.

Pulled the TPump again (ripping the gasket in the process) and could find nothing to prevent it from pumping. I pulled my hose off of the gauge port and put air to the TPump outlet and got fuel out there. Opened the bleeder on #4 pump and put air to the outlet port in the filter housing and got good fuel flow out there. Also, somewhere along the way, I opened the front bleeder and put air to the hole and got fuel out the gauge port.

So it appears that there is no blockage from the TPump to the injector pumps.

Something odd that I noticed is that we had the filter housing bled but no fuel was coming out the gauge port fitting.

I'm stumped right now. I now have a pretty good idea of fuel flow on this thing, and I just don't understand why we aren't squirting fuel.

In related news -but I don't want to get sidetracked on this- I had an idea on why it could have low compression after just sitting on the trailer for a day. It had sat for a few years, so maybe it got rusty in there, but ithe rust held enough compression for it to start and once started it had enough to run, but the rust tore up the cylinders to the point that now the compression is too low to start.

I may take an injector down to a Machinist and have him make a compression tester adapter. Should be pretty easy to copy the threads and put a lip on the top to seal it, then drill and tap a 1/4 NPT in the top. Could get fancy and have him put a hex on the top for a wrench, but I shouldn't need that.

Anyway, just figured I'd give an update and see if I came up with any new ideas while typing or see if anyone else has any new ideas.

Thanks for reading.

Thanks for the update, this tractor is giving us donut dunkers lots of entertainment, but obviously driving you nuts.

I'm surprised someone smarter than me hasn't chimed in already but as I said previously, I think that filter tower pressure is normally less than 10 pounds.

The few times I've changed fuel filters on my D2 or D4 it seems to take for ever to re-prime the filter tower if you are relying on the pony motor to crank the main motor and fuel transfer pump, quickest way is to fill the diesel tank full, open all the bleeders, go grab a coffee or a beer and let gravity fill the system, or some people gently pressurize the fuel tank using a old inner tube over the fill spout.

If the injectors were squirting before they will squirt again, I'd suspect air in the system now.

Early Cat diesels are low compression engines, and Cat never liked discussing compression numbers, they did however put out a tech release way back when, like in the 1950's, and in that they discussed compression figures at cranking speeds and a normal Cat D2 diesel was around 550 to 600 pounds, at 445 pounds they said the engine might be a bit harder starting, on the larger D339 and D342 they quote 445-485 pounds at cranking speed, the D318 is 530-580 PSI. Though I'm just a farmer, so take everything I say with a pinch of salt.

I wouldn't get too hung up on compression numbers for the diesel just yet, solve your fuel issues first, that engine ran previously, and yes, some bores might be rust damaged, but surely not all 4, and the bores not rust damaged should be puffing black smoke if your fuel system is back to spec. and bled out.

Those Cat cylinder liners are the hardest metal on the planet, Cat used to brag about how hard they were, and it was accepted practice back in the 50's and 60's to bed in new rings and liners in glazed bores using Bon Ami kitchen cleaner poured into the inlet manifold, Cat actually had a spec for the amount of Bon Ami to use for each size diesel and it wasn't a teaspoon full!! You are a Mechanic, it is possible the rings are frozen, that's common for these old engines isn't it, after years of sitting, there are thousands of good stories here about old dead Cats being driven hard and hot back to good health, pulling a big plow or heavy logs for a day or 2. Old Cats love a good flogging, and stuck rings can be overcome once the engine is running.

I have a 1936 built 3 cylinder RD6 Cat here that starts easy and runs great all day, it has a 9 litre diesel engine, 6 years ago I pulled the head off with the help of Canadian member Roger Myram who was visiting Oz at the time with his family, I'm not joking when I say I could almost slide a finger inside the top of the pistons and the cylinder wall and I could easily see the top rings in each cylinder, I reckon the end gap of those top piston rings was about 1/2"!! That tractor runs like a train, burns about 2 litres of oil in a full day plowing hard, I can live with that, I only use the tractor a few days each year.

One thing to watch when you get the fuel system back in prime and are trying to start the diesel with the pony motor, if the pinion latches on the pony motor are a bit tight they will not release and will "hang on to" the diesel motor preventing it from speeding up and firing off. You will be seeing puffs of black smoke as the cylinders fire off, but the diesel just will not start, the pinion latches might be tight and the pony is acting like a brake on the diesel, it is also possible for the diesel to fire off and take the pony motor with it too, over spinning the little gas motor to death.

If you can get the main motor warmed up using the pony, and you have good oil pressure, I wouldn't be afraid to pull start the tractor, we did that with the RD6 when I first dragged her home, she had spent at least 20 years sitting out in the open with clutch compartments full of water, though I spent a week prepping and cleaning oil compartments and soaking cylinders with loose juice first obviously. It was funny when she fired off, BruceOz was driving her as she was being towed, I was riding next to him, it took about 20 yards and she came to life spraying us both with a shower of oily black crud out the exhaust, we were covered in Cat pox!!

Keep at her, you will win.
Mike

"Neil" wrote:

I'm definitely not smarter than Mike, but 6psi at the gauge port is plenty. The way to tackle this is start at the beginning of the "chain" and work your way forward, proving that you have adequate flow. Start with the inlet from the tank into the transfer pump. Disconnect it, and let it flow for a good minute and fill up a bucket. If it slows down after a bit, you have a blockage somewhere upstream. Once that's good, then go to the top of the fuel filter tower. Again get good flow out of the two bleeders for a good minute - don't shortchange it. You want to see good sustained flow. Do the same for the pump bleeders and finally the injectors. Once you have done all of that, then you know your fuel system is ok. If you skip anything, then the fuel system is not proven.

Once you have it bled, then as Mike says, you can tow-start it. The benefit of this is that you can get it cranking faster than the pony will crank it and if you have a low compression, the extra rpm can help overcome that. But before towing, run it with the pony under compression for a good five minutes to get heat into it. Don't turn on the fuel during this time, and make sure the governor is firmly closed.

Mike and Neil, and others, thanks for sticking with me on this. It's much appreciated. It's good to find a forum with knowledgeable, helpful and friendly people.

So right now I need to get gaskets and seals for the TPump. I have a local Cat dealer but is there one that supports the members here? I do like to support those people when possible.

Yesterday we did a phone a friend and he said 25 PSI, but I don't know if he was just guessing or if he has actually put a gauge in there, so for now, I'm going with what I'm reading here.

Right now, I'm thinking of putting it on a trailer and hauling it out of there to a place where we can try pull starting. If we can't pull start it, I think I'm going to have to pull pumps and see if there is anything going on there.

Oh, I bought some MMO and was going to put it in the cylinders for the night, but forgot to. I'll do that today for S&G.

Sadly there are no Dealers or parts suppliers linked to this bulletin board in the USA that I'm aware of, but it would be nice if there were, actually finding the parts for these old Cats is getting harder each year, though luckily the common bits for the D2 and D4 are still available from the Dealer network, items like filters and most bearings, many of the gaskets.

I have bought a lot of parts from Florin Tractor Parts in Sacramento over the years, their prices were good and they had a lot of the hard to find things, plus their staff were great, not sure how they are going now, but I'd suggest you call them first. John Parkes at General Gear is another good guy, he's in Boise Idaho. Use the online Machinery Trader website, punch in the part number and it will tell you who has the part available all over the world.

My Mum used to say, "believe nothing you hear, little that you read, all that you see", when it comes to saving these old Cats I've learnt to not believe everything I get told, even top flight Mechanics can get the advice wrong some times, try and find a older retired Cat Mechanic you can bounce off, a guy who has actually wrenched on these things over a lifetime, I'd trust him for sure.

Getting the tractor home makes sense, much easier to work on, plus with the hours you have spent on this tractor you must just about own it by now at $165 a hour!!!

I've met Neil, he is A LOT smarter than me too.
Good luck
Mike

$165/Hr! Is that Canuck money or real money? I don't know anyone around here that charges that much.

Now I'm wondering if there could be blockage between the feed pipes under the pumps and the pump chamber. If I can't get good fuel pumping out the pumps, I think I need to pull one to see. Squatch has that video and it's nothing big, but one thing I noticed he did but didn't mention because it's so natural to him is that you want to hold the plunger into the body as it's removed. I noticed he would push it up, then hold it with his pinky once he couldn't hold it from the bottom.