Ok...thanks for these. I will wait until i get my compression tested and then post results to see what i should do.
Help Support SkidSteer Forum:
I dont know if it was oil on the glow plug but it was darker then the diesel i thought but i guess there wasnt really alot on there to tell for sure or else i couldnt tell the difference. there are 1380.0 hours on here unless the meter ticked over which i doubt.
Also, that oil leak the previous owner had, could that have been oil coming out of the breather tube down the back of the engine? If the rings/ seals are bad?
It could have been yes, when its clean its easy to tell as blow by oil will be black, hydraulics is a honey colour usually.
Well, my adapter FINALLY came in. The results are as follows:Cylinder 1 (Closest to the flywheel) was 310 PSI, cylinder 2 was 300 psi, cylinder 3 was 100 psi. With that being said, what should this mean to me as a rebuild. What should i plan on rebuilding? Old Mechanic, that link you sent me they have a couple of different packages i could buy but what do you think makes the most sense? OR... should i yank the engine and then see what it has to show me once i can see inside and what needs to be changed out? Thank you guys for all your help..:>
Also, when i did the test, my adapter would get alot (almost dripping) with black fluid probably oil. Is this all the same problem or could this be something else?
OldMachinist
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If there's no hurry I'd pull the engine and tear it down to see what's wrong. Might just be stuck rings on the low pressure cylinder. Did you get your service manual yet or will you need some of the pages on engine removal?
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Ok. I was also told to take the valve cover over and check the valves as i might have a stuck valve as well so i am going to tear into that so anything that you have on both of these would be helpful as i have not gotten a manual yet. There is no real hurry but i do have a couple of jobs lined up for it when i get it all done so the sooner the better but i want to do it right instead of just a rush job.
OldMachinist
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The valve cover is is removed by taking out the three bolts on top and removing the blowby tube and it lifts right off. After its off rotate the engine and watch the rocker arms for any valve stems don't return back up with the arm. The couple of manual pages on engine removal are here in a Word document.
http://www.mediafire.com/?dmt0mo139tj
Thanks a million for these. They will come in handy. Ok, this morning i pulled off the valve cover and when i spun the flywheel byhand i could watch all the valves moving with the rocker arms. However, on cylinder 3 the furthest from the flywheel, the valve on the right (when looking from the back) seems to operate correctly but i never get the rocker arm to be somewhat loose. Its like there is pressure still there from the valve being stuck or something. When i look at the side with the spring i notice that the valve(?) seems a little higher then the rest. I can see a rubber O ring at the base where it meets the block. I cant see that on all the rest. Does this mean it needs adjustment or is something broken?
OldMachinist
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Sounds like the cylinder head needs to come off to see if there's something hanging up the valve or the valve is burnt or the seat is worn. But if you wanted to chance it you could adjust the rocker until you have the .006-.007" it calls for and retest the pressure.
Agreed, i was thinking take the head off and check the valve seats. The compression should be 400+ but even 300 *should* work if you can get it started.
If it was me, I'd pull the engine out, head off, sump off. Pull the pistons out check the bores for wear and roundness, if they are ok give them a flex hone and give it a new set of rings. Check the head and if the valve seats are an issue get them done.
I believe the black gunk is diesel and engine oil.
I have the repair manual here somewhere that gives you all the details, but i think you got that already?
Ok. Thanks for all the help guys. I think i am going to tear into the head tonite. Should i yank the engine or can i look at the cylinders with just the head off? If i can inspect the cylinders with the head off would that be easier to check or should i plan on yanking the engine and do it that way? Also, is there a neutral position for the drive wheels in case i have to move it with the engine out/torn apart? I am planning on moving it but it wouldnt be for a week or so. Right now if i crank it over i would have enough hydraulic pressure to drive it onto a trailer, or is that a bad idea to crank it over to move it?? I have the details on the engine removal but nothing on the engine itself. Tazza, whats a flex hone? Old Mechanic, i was able to adjust that one rocker arm and i still get the same compression (110 PSI Cylinder #3) so i think something is wrong with that cylinder.
OldMachinist
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The engine and pumps come out as an assembly so you'll be able to move it slowly with the engine out but it will be messy as the oil in the drive motors will come out. You can see the cylinders with the head off but you can't tell if it's a ring problem. Like Taz said I'd yank the assembly and tear the engine down and check it out. The manual says the compression should be 337-448 psi.
ok. I will plan on yanking the engine out. I have a workshed with a nice bench to use so i will just do that. Is there a way to put these in nuetral to roll them or is it easier to just crank it over as it is now and drive it on a trailer?
A flex hone is like a bottle brush with abrasive material boneded to the tips, they may only be common over here but a bore hone would do the same, just get that cross hatch pattern in the bore by using a drill and going up and down with it spinning.
I agree, pull the engine then you can really check the bores but you only need to drop the head and sump, don't pull the timing cover on the front as its really not needed.
An update. Today i pulled the engine(THX FOR THE PAGES OLD MECHANIC THEY HELPED A LOT) and took the head off. The valves on the bottom side had alot of carbon build up and even some small chunks of carbon. I called a a buddy of mine who owns a machine shop/engine shop and he said he can clean the head and check the valves. I dont know if that caused the compression problem but he said he will clean it up and run some vacuum test with the head and let me know tomorrow what he finds. The cylinder walls were clean and shiny, so i know the cross hatch is gone so i think i will plan on doing the flex hone like you suggested Tazza and new rings and seals. Any word of advice on these before i get into it(Buy the flox hone attachment and use a drill? Rings and seals from a dealer or the website you sent me Old Mechanic??etc.etc.)? Also, if i run my finger along the cylinder walls they feel really smooth but there are small VERTICAL lines that i can see in the sun but i cant feel at all and if i run my finger up and down i can feel a little lip/bulge about 3/8" from the top that im guessing is from the rings wearing down the walls? Is this a major problem or will a flex hone fix my that? And how do you know how much to flex hone it? Also, should i run a macrometer to test the cylinder walls to see if i need to rebore/replace the sleeves? If so, do you know what the tolerance would be on this? Thanks for all the help on this. It is MUCH APPRECIATED:>:>:>
Tazza, do you have a repair/rebuild manual for a D750? If i have to replace the rings it would be nice if i had something for it to look at. Otherwise, where would i get one? Should i do the bearings or how do you check if those are good?
I know i have one for a D722 it may cover that engine too plz send me an e-mail to remind me! its in my profile somewhere.
The lip you speak of at the top is called a ridge, you are rite, thats where the rings run up to. It will need to be removed or you risk breaking the new rings. It can be done with a die grinder and spiro bands. You don't need to buy a flex hone as they are rather expensive, you only need a fine cylinder hone, they are a few $$ just use a lube when doing it, even WD40 works. It prevents the stones from clogging up.
How many hours has this engine got on it? does the hour meter work? as i was sure you said it had real low hours.... The engine should have still been in good shape.....
