Okay, since the Texas weather went from 0 to 65 much faster than the average car, I thought I'd go out and start and check the old Case 550G today. Cranked up fine, thought, well, battery didn't die. Then smelled oil. Cut it off immediately, looked underneath, and saw that I'd lost a quart or two. Thought (thought) I had plenty of anti-freeze, since I just put in a new water pump in June, and replaced it then. Then re-thought, I did add water several times while clearing brush during summer and fall, because radiator got hot and it plugged up. Short story, took off right side cover, top freeze plug blown out. I checked fluids before starting (oil was right on the top mark, and I had marked that I changed oil in September, right after finishing brush work, and washing dirt out of radiator). I admit I only checked water in the overflow tank, because I've been running it in the heat, and I know I've had to put water (yeah, I know) in several times, but I was sure it was moving (and it was still green). Anyway, the big freeze plug let me see there was still coolant (probably not enough anti-freeze, although I could smell it, to prevent freezing at 0) in the system, but okay, I screwed up. But where did the oil come from? I figured the block was split (I know how useful freeze plugs are, not really at all), but I checked the oil again, no sign of water, but I couldn't see the coolant in the top of the radiator. I decided to track down the oil leak figuring I either have a 7 ton paperweight, or a source of parts to list for sale. When I re-started it and quickly cut it off, I saw the oil was literally pumping out of the oil pressure relief valve. My question after this long explanation is how could the engine freezing, or the blown out freeze plug cause excessive oil pressure without raising the level in the oil pan? Oh, and the oil level on the dipstick dropped a corresponding amount to the oil that pumped out on the ground.
Maybe take the relief valve apart and look for problem with it. Remove the oil filter and cut it open to see if something is in it that shouldn't be. A lot of people call expansion plugs in blocks -freeze plugs. Those plugs have nothing to do with freezing or freeze protection. They are used to plug the holes that were put in the block to remove the sand when the block was cast.
Take the relief valve apart and there will be a seal cracked, or something cracked. From high oil pressure and a jammed relief valve possibly? Check it for free operation before you put it back together. Nothing to do with the antifreeze except the cold got them both. Core plugs work to protect from freezing as you've seen, sometimes. That's not their purpose though. Just what they get called when somebody gets lucky and doesn't crack their block.
Yep, I know they aren't for freeze protection, and know they are called "expansion plugs" but, as I was growing up watching the "old guys" work on stuff, they called them "freeze plugs." Thanks for the input, I'll try taking the pressure relief valve apart, I just really couldn't figure out how freezing coolant could result in enough excessive oil pressure to blow a quart of oil out in a few seconds. (I would have expected less oil pressure from a cracked block, rather than more.)
My comment about freeze plugs wasn't directed towards you in particular, Old Sarge. There are a some people reading these posts, and a for some of them this is new to them. I keep that in mind whenever I post an opinion or comment. It could be a coincidence that the cold temperature of the coolant and the relief valve happened at the same time. I'm sure you will sort it out.
Maybe you had some moisture in the valve and it froze and cracked pull it apart could be just a o ring
Pulled the relief valve out today, looked okay, o-ring replaced, no signs of blockage, oil is still clean (only put 5 hours or less on it since oil change). Will take assembly apart tomorrow and see if the cold oil relief valve is shot. Oil was gushing out around the plug on the relief valve, and not just a trickle. I'm not big on coincidence, but maybe. I am still trying to figure what could happen to "increase" oil pressure to the point it opens the relief valve. It hit 75 degrees or more today, right now it's in the upper 50s, so everything even deep in the engine should be thawed out, although a week ago the temperature was right at zero. (Which is why everything froze, and even though I had some anti-freeze, I guess I'd diluted it enough that it wouldn't handle zero to five degrees for something like twelve hours.) I know there may be a break in the block right behind the oil-cooler/oil filter mount, but I would think there should be some sign of water in the oil. (or oil in the water, which I haven't seen either.)
What was the oil pressure gauge reading when it was running ?
The gauge doesn’t read in psi, when it starts, until it warms up (I am not running it to that point right now), it is at the top of the “green”, but not into the warning (yellow), and after warmup it settles in about the top 1/3 of the green area. Been like that since I bought it at an auction 5 years ago. Hour meter hasn’t worked since I have owned it, and it runs off the oil pressure gauge, so I haven’t messed with it.
Should mention gauge didn’t read any higher than it has been doing, so no idea on that.
It isn't unusual for a block to crack on the outside only from frozen coolant. I've only seen one that cracked both in and out. I don't know what the thread size is on the relief valve, but I would try to replace the valve with a pressure gauge long enough to see what it reads there.
Do you know what is around the plug that was leaking? I'd guess there was some water trapped in the relief valve that froze, and it was a very short pressure spike that caused it to break. Sounds like the relief valve is working fine when running. I'd still take it apart and inspect, but probably nothing you could have done to predict this or prevent it, short of lower viscosity oil, block heater, oil pan heater, maybe avoiding short run times in cold weather to avoid condensation.
Okay, I think (think) I've got it now. Got the oil filter/oil cooler/regulator/relief housing off (after removing a lot of other parts, but that's another story). There are a series of hairline cracks in the housing (which is a light, maybe aluminum casting? Didn't have a magnet with me to test it). One of those actually comes out under the shoulder of the cap screw at the top of the relief valve, hidden until I took the whole shebang loose, and maybe (probably) that is where the oil was pumping out when I ran it, rather than having enough pressure to overcome the spring in the relief valve. The cooler looks okay, and I don't have young eyes to inspect for ultra-thin cracks, so I guess it'll get replaced too. Now the real roll of the dice, $25K worth of small dozer versus a couple or three hundred bucks of castings and gaskets. I now suspect that there isn't a "high oil pressure" problem since there was ZERO gum or sludge in any of the oil lines on the housing or cooler, or in the ports into the engine. (I have seen worse on a lot newer engines than this early 90's built machine.)
Well, not done yet. The oil cooler core is not like the one in my manual, or any of the ones I can find on the Case website or any machinery parts sites. It doesn't have a stack of "plates" on the inside part, it is simply a "U" shaped tube, about 5/8" in diameter, sticking off the back with two ports leading into the filter/cooler/relief valve housing. Anyone seen anything like that?
How about a picture of the relief valve and the cooler? a close up of the cracks too. I was misunderstanding this thread from the beginning. Was it already 65 degrees when you started the engine and it started leaking? I was also focusing on the relief valve, and ignoring the oil cooler which is in contact at least with the coolant.
Yep, it was 65 or warmer. I should add that today reached about 80 degrees, (last Tuesday, it was 5 degrees) which kind of explains why things break. Thermal shock is a way of life around here. I've tried to attach pictures of the oil cooler, and a couple that might show the cracks. (I don't have a real camera, just my phone). The cracks are all pretty narrow, but I can tell the one by the plug goes through.
Done by someone with experience cast aluminum is generally a successful weld repair using Tig. Transmission cases and oil pans are commonly welded.
Coolant freezing 100%. Find somebody to weld it if you can. Might not be that hard to find a used part, it's not like they wear out commonly. Find the part number and parts search on machinery trader or just search engine. Or Jbweld it if you dare.
Thanks for the suggestions, a used part is $95 and should be here next week, and being 30 miles from the nearest town with a "welding shop" and not having the skills or equipment to TIG weld it myself, and the fact that the majority of the cracks I can see and feel with my fingertip don't even show up on pictures, I figure $95 is a cheap and easy way out. Now, if that's the only thing wrong...
Okay, I've looked high and low, and nowhere can I find an oil cooler core that looks anything like the one in the picture above (the one named "Oil cooler back". I think this one is not leaking, but I'm not sure what one loop of about 5/8" tube circling in the water jacket for about 8 inches of length is actually doing for the oil temperature. Anyone got any guesses? (Honestly, I'm probably going to put this one back in, when I get the replacement housing, just on the theory of "if it ain't broke..." I never noticed any oil problems, but that doesn't look too effective.
Looks like a oil cooler bypass should be a element there never saw one like this
I looked at the 55G parts and it shows a oil cooler element someone might of cobbeled that up you need a oil cooler element in there especially if it is turboed. number 12 is the cooler where you have the tube
One trick I've done with our TIG welder is just fuse the parts together by melting the material already there (ie- not using any filler rod). Work great on cracks like this in aluminum or cast iron where there is low/no pressure. I learned that from a professional TIG welder who built scientific vacuum chambers- amazing work. Point is, you sometimes you have to tell the welder this because some welder's only use TIG as the exception and aren't very knowledgeable in that area. But for $95 bucks for a used part- that's definitely the route to go here. It was definitely cold here last week and I hope I don't have any damage either. Will take extra precaution when starting up the old iron. Hope you get your machine running.
Howards Enterprises shows a cooler element in a 550G too 69.00 they are good quality been using them for 20 years don't know if they sell to public if not I can get it for you
Howards Enterprises shows one in a 550G too 69.00 good quality been using them for 20 years I can get you it if they don't sell to public
Everyone reading this thread should, right now, go to the parts store or a truck dealer and buy several cases of 50/50 premix coolant, preferably Cat EC-1 equivalent. Then, give away any jugs of full strength antifreeze so you’ll never be tempted to add water to a radiator again. You don’t even know the pH or mineral content of that water you’re adding anyway. Now, put those cases of 50/50 in your shop, in your service truck, and somewhere on your fuel truck or fuel wagon. Put individual gallon jugs anywhere you can find a tool box or hidey-hole on every piece of equipment you have, and in your big truck. And tell everyone that works for you that they will get their axx kicked up between their shoulder blades if you ever see them putting water in a radiator. And sleep good every winter night from now on because you don’t have to worry about how cold it’s going to get.
Well, I don't drink bottled water, either. And somehow, I suspect folks might find my "axx" a little harder to kick than average.
Well, strange looking "oil cooler" head or not, when I put it back in, leak slowed down (I didn't replace the gasket, was just testing) but now I have oil in the radiator. No water in the oil pan, oil level hasn't changed, no "milky" looking oil, just scum about 1/2 in thick in the radiator. I don't know why I thought I could re-use the oil cooler, if the housing cracked, I would figure it would go first, but I didn't see any cracks. Mistake. Ordered another oil cooler, and all gaskets. (Thanks for the suggestion, Dave, found a used one at the same place I got the housing, for about that same price. So I'm still into it only $160, plus new gaskets (which cost almost as much as the oil cooler). It ran fine with the replaced housing, with no smoke, had a little seepage around gasket where I kind of expected it, near the top where the gasket looked kind of "iffy". The oil pressure normalized when it warmed up, just like it always does, hope it's just the oil cooler, and not a crack in the block where the oil pressure is high and the water pressure is low, but I'm not ruling that out. So if I can get it fixed with this, and a "flush" to get the oil out of the cooling system, maybe I dodged a bullet. At least I can get it running enough to put it on a trailer and move it to my new place, 200 miles from here, where, if I need to, I'll replace the engine (short block, I hope). I always knew retirement would be restful. I can't complain, I have so much to do, I go right to sleep when I get a chance.
Good read. Let’s hope you did dodge the big bullet