Last fall the D9G (SN:66A7869) that we've been running with started burping out coolant from the pressure relief cap when in operation. We thought that we were having a heating issue and because we were close to the end of the job we just brought the machine back to the shop to give it a once over. We pulled and replaced the relief cap after finding that it was corroded. We also found a few other leaks on the cooling system we then repaired and thought we were all set. We had a new job come up and decided to put the machine back to work pushing pans. Before taking off to the job I put the machine out back to push against some dirt mounds to get it up to temp. Sure enough the relief cap starts to burp out coolant. The odd thing is that the motor was not hot, not even close to being hot. What I did notice is that the cooling system pressure gauge was showing high pressure in the system. When the pressure gauge would get up into the high side, it started to burp. I let the machine cool off and checked the coolant level and the color only to find the radiator full and that it was still green as new. I ran the machine some more and the pressure gauge would build up pressure as I ran the machine, burp a little, and then stop for a while until I really worked the machine hard with long hard pushes against the mound and cycling the motor rpm up and down like you would pushing pans. If I stopped a for a few minuets the pressure would come down to normal. At idle the machine would show normal pressure. So here is the question is this a simple case of a bad head gasket? Could it be a bad seal on the precombustion chambers in the head? I would think that if the head gasket was blown I would see soot in the coolant and the pressure would stay elevated? I'm a little stumped here. What do you guys think?
Do you have a kit to test for the presence of combustion gases in the coolant.?
I don't, however a quick google search says I can get one pretty quickly and cheap. What should I look for on the test results?
I would suggest whether the result of the coolant analysis is positive or negative for combustion gas would be a good place to start.
Fair comment
Nige and a few others on this forum likely have much more knowledge on these than I do but if I remember correctly the D343 was known for cracking heads, usually a bunch of tiny cracks that were very difficult to repair. I worked on one in an old 988, sent the head in to be welded up and when I re-installed it we still had a slight amount of bubbling. I called the company in Portland, Oregon who did the head and they told me to get 4-5 tubes of silver solder and dump it in. It worked, not necessarily the right way to do it but like I said, it worked. I'm not suggesting you try to repair your machine with silver solder but you might want to be prepared to find a cracked head when you pull it.
Hopefully it doesn't come down to this but this is good to know that these engines have known problems with the head. Like many older machines, I am finding that parts are becoming scarce.
Drain about 2 gallons of water out of radiator and try it. What do the temp gauge read? Did you replace the pressure valve under the bolt on cap? Did you replace the water regulators in the head? That tractor should have a D353 engine. You don't need any testers just warm up the motor shut it off and fill the radiator full ,start motor and watch for bubbles. Bad Bob
Once you confirm the presence of combustion gasses, I would consider pulling the pre-cups and inspect. Could be gaskets, a cracked pre-cup or a “worm hole”.
As said previously make sure it’s not over full. It may find its own level.You might just be putting water in it to spew it out.
You can often remove all the mystery about diagnosing combustion gas in the cooling system with the Cat bottle test. Plus, obtain quantitative data you can compare to spec. A 5-gal bucket, Nalgene bottle and some 3/8” tubing. Cheap and relatively easy.
I give another vote for checking the precups. HeavyEquipmentForums
Plugged radiator cores can cause the high pressure on the top of the radiator as well. They will also cause a vacuum or lower pressure at the inlet of the water pump causing boiling coolant that is never seen on the temperature gauge. I agree that D9 engines were D353 models. I also agree on the pre-cups.
If we get confirmation of the gasses in the coolant then we will definitely pull these out to check them out.
Thank you sharing this photo. Certainly gives credence to needing to check them. I will go ahead and start checking on availability to see what that looks like.
When you check for bubbles fill the radiator running over full. The correct temp. gauge shows the temp corrected for pressure read on the pressure gauge. If the precups are leaking they leak both ways so you would be using water and at some point the motor would Hydo lock. Have you pressure checked the cooling system yet? If you find no bubbles drain radiator down about 2 or 3 gallons and run it to see if it still purges water. Bad Bob
Were working on getting the scrapers all back going, we've had a rough week these past two weeks on failures, and once they're up we'll start trying out these checks.
Well we finally got the old D9 into the shop and get the chambers pulled out. Sure enough they were pitted and corroded pretty well. Not as bad as this but close enough. Replaced all 6 of them and the glow plugs for good measure. Costex had all the parts and not priced as bad as I thought having compared to what Cat wanted for them. Bad thing is that we still have pressure in the radiator. So head gaskets here we come. Good times all around… More to come.
Thanks for the update. Heads off and liner heights measured I suppose. Let us know how you get on.
Update: We sent the heads out to get checked over and we have cracks in both heads at the precombustion chambers. Working with Costex now to see about replacements. Nothing here in Atlanta available through Yancey. Only the Penn. Cat dealer Cleveland Brothers, has to reman units available for near $7K/EA + shipping. Good times working with tired iron. Costex appears to have bare heads in stock. Can the parts all be used off these old heads to build back these bare heads? Or should we swap out springs etc. for new? Interesting note though, the guys that checked over the heads said that our valves were different sizes on each head. One head had 3/8" valves and the other 1/2" valves. The rep that called me wasn't there for the tear down and could not tell me if the valves were intake or exhaust. Will be trying to get the full write up to share later on when I can get it. I wonder if one of them was worked over in the past or taken off a difference machine?
Excavator you were right, we had cracked heads. The silver solder idea is starting to sound pretty good based on the pricing I am getting back so far.
Was that on inlet valves, exhaust, or both.? A number of years ago I recall that the 3500 engine exhaust valves were increased in size from 3/8" to 1/2" diameter. I don't know if a similar thing happened to the D353 way back.
Home | Mysite www.dieselcastwelding.com They can fix your OE heads or get whatever aftermarket you such desire. The local yellow store has used them for decades.
I intend to find out. I am curious to know myself. I am currently in the process of ordering a manual for the engine. Then I can have a little better idea of what is what on this old boat anchor. I also want to know the spec for straightness on the block before we sit the heads back on it. The shop manual I have for the machine itself doesn't have the engine section included in it like the other manuals I have purchased.
I'll have to give them a call and see what they can do for us. I have dealt with Blanchard Cat in South Carolina and they deal with a company I think also based in the Mid West that helps them to repair transmission cases.
You might want to give American Crane and Tractor a call (ACT Parts). Now owned by CGR. CGR used to make complete heads for the D342. Don't know if they make heads for the D353. We used to run a new CGR head through the machine shop to bring it up to spec. Never had any problems with them.
Different size valve stems are common enough. You can reuse all the parts if they are up to the mark,although springs are a good thing to replace. Non Cat heads are easy to source in the UK,and I imagine you can get them over there too.I’ve no issues with using various non oem parts on 60 year old Cats. As for stitching them back together,I’ve never been down that road simply because I’ve never had to yet.
Like I've said old stuff is for hobbyists not for using. D8s and D9s with conventional tracks are now antiques. And priced out of this world. Just nuts.
After some calls to different aftermarket suppliers I went ahead and bought two new heads. They weren’t too bad in comparison to what I was seeing from Cat. They cost right at $2,900/ea. they’re supposed to arrive next week.
The 1/2" and 3/8" valves are common to find, that is 1 head running different valves to the other, if you change the guides you can fit what ever you want to run as both size guides and valves should be still able to find, the change in size was to reduce oil consumption through valve guide wear, the exhaust guides near always need changing, a common trick is to drill down through the guides to 5/8" to make them easy to press out as they can hang in tight, I tend to stick to the 1/2" stem valves as I always keep a few, the $2900 per head seems a bit high but it might be on the spot, the last head I had to find was £900 but that was 4 years ago, I might have just been lucky and had a cheap deal, don't fit those heads without stripping the oil coolers and cleaning out the gunk in the water side, as this is the possible cause of your head cracking, the other cause is incorrect shut down, this takes around 10 mins+, or running out of fuel when hard at work, anyone can spend $$$ but you would be a fool to do it twice as the heads don't crack without a reason???
Thats 2/3rds of total machine with blade and ripper, scrap value, course we never get full scrap value and then theres the work turning it into scrap.
Sorry but to me its sorta not smart to pay the over inflated prices on these 50 plus year old dozers, there is just so many hidden issues with them and then the parts issues. Its not like your purchasing a completely restored old collector car, its most likely very well used, and full of metal fatigue every where.
Chidog, I cannot make an argument against most of that you're pointing out. This machine is the definition of worn out and is very very tired iron. However, the replacement of the same machine with a newer one makes little to no sense for what volume of earth we move on an annual basis (X<600K CY typ.). Paying $6K to keep this machine moving even if it is only another one or two steps closer to the trailer to go on to the scrap yard, is less than what I would pay for any decent enough D9N or newer machine to do the same task of pushing pans through the cut. Would I love to have and want a newer one, absolutely. Can I justify the cost of it on paper, no. We lay more pipe and make more of our money there vs on the dirt. So consequently, most if not all of our excavators, small dozers and wheel loaders are new because we have to depend on them to stay up and running so the crews plow on ahead. I believe this is ultimately what you're driving at. Even if we went with a newer high track, but still a used piece, we'd have the same likelihood of having a worn-out dozer to contend with. I've got nothing in the machine relative to what I can get out of its use in the cut. When it is totally used up, like needing to have a new U/C for example, we can just park/scrap it and walk away or go buy another one to put it back together and so on. Regarding the hobbyists being the only folks who'd keep these old machines running, I would push back on that. If there weren't a market for these machines then companies like Costex and Regal wouldn't exist in the capacity they do. South America and other developing areas of the world are loaded with these older machines for many of the same reasons I list above and due to their generally being fairly simple to keep up due to lack of sensors and electronic systems to run the engines and transmissions etc. These machines will all die off soon enough, but for now they do still have their place on the grade.
TC, Pretty sure this failure was from improper shut down. I'm glad you pointed out the cleaning of the oil cooler. While its torn down I will ask our mechanic to pull it off and clean out.
I just wish the prices would drop, I'm always looking. The day the prices drop is the day I won't be able to climb into the seat.
631G. You make excellent observations in what you’re saying about the need to run older iron,especially D9 size machines. Unless you’re buying a D9T with nowt more than 3000 hours on the clock,you’re potentially dicing with some expensive breakdowns.Its simply a gamble.Plain and simple. On a positive note.I’m happy for you that it’s only cracked heads and not liner or block issues.Thats a different level of wallet rash if you need to go poking into the block. As TC tractors says,coolers need cleaning up throughly and you may need to personally supervise the starting and shutting down operation of this machine yourself from now on. It’s also vital not to let the beast run out of fuel.If it does,run the starter motor to circulate the water around the heads.Could be the difference between cracking heads. These old D353 are not like any other engine in your fleet.They need starting in the morning and left on low idle for 20 minuits to warm up.That helps with tranny pressure too. At break times,do not switch it off if you can help it.Only after 10 minuits of idling. At night time,leave it running 20 minuits whilst you check over the scrapers or something or you will crack heads again. People used to worry about damaging turbochargers on those early engines by shutting them down too fast.Personally,I was more worried about cracking heads,shocking liners or cracking blocks. I have sacked men on the spot over this vandalism.
It will be interesting to see in another 20 to 30 years the number of by then 40 year old electronically controlled machines still running compared to the number of mechanical hydraulically controlled machines of the same age running today. Will machines be scrapped not because of mechanical issues, but rather electronic parts and wiring is no longer available and no aftermarket replacements due to software issues as well as these machines are run by microcontrollers that need programming with software.