Well, I lost my old engine to a broken rod. Punched two big holes on the side of engine. Managed to drag the thing into the garage before winter set in. That's about two month ago. Finally got the right refurbed engine. As of today, I put the engine in, connected the hydraulic gear pump, drive belt and muffler. I tested the engine before I put everything together, just in case something not right. It fired right up, running smoothly with the drive belt properly aligned and gear pump running well. I only let it run for a few seconds, well maybe 30 40 seconds not wanting to heat up the engine or ruin the pumps. Like I said, it's been on the stand for quite a few weeks. I did not cap the lines (return line to the reservoir, filter mounting plate etc. ). I did cover them with layers of cloth and bond with rubber bands. So, except the fluid in the cylinders, most of the lines and new filter are probably empty. I filled the reservoir with new fluid. While I have the machine test running (without radiator), neither the tracks nor arms are moving. My question is: Does it need to be primed somehow or the gear pump primes the entire system? I did not find any hints in the service manual. Thx in advance for your help. Erwin
Help needed to properly restart my MT55 after an engine replacement
- Thread starter eyyu
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OldMachinist
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Don't run the engine without coolant anymore unless you want to replace a cracked head.
The system should prime itself.
Start the engine, running at about half throttle, slowly move the steering forward and then reverse to get fluid moving thru the drive motors. After the tracks are moving smoothly then raise and tilt the arms to purge some of the air from the cylinders.
Turn it off and check the fluid, add as needed.
After you it get down off the stands you'll likely need to run thru the same procedure to purge the rest of the air. It may take using it for a few hours to get all the air out of the cylinders.
The system should prime itself.
Start the engine, running at about half throttle, slowly move the steering forward and then reverse to get fluid moving thru the drive motors. After the tracks are moving smoothly then raise and tilt the arms to purge some of the air from the cylinders.
Turn it off and check the fluid, add as needed.
After you it get down off the stands you'll likely need to run thru the same procedure to purge the rest of the air. It may take using it for a few hours to get all the air out of the cylinders.
Thx for the useful information. Now I feel good about it not moving yet. It will need a lot more than just a few seconds to get rid of the air in the system. I will not run long w/o the coolant. The reason I felt safe to briefly run it to test is that I want to make sure my new engine runs well before I put all the effort the assemble all those tens of parts in the very tight space. The head or the exhaust manifold did not even get warm after. I saw people do this a lot on the net. But, thx anyway for you concern. Erwin
One more thing to ask: I did not do a good job tagging all the wires when I disconnected the wiring harness from the old engine. Now I can't figure out where one of the wires go. It's a large (maybe 12 gauge) red wire from where the alternator wires are. Exactly the same size as the charge cable from the alternator to the battery plus, same color red too. It extends all the way to the front. Any ideas?
Zorack
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You might want to get a MT55 service manual,check either ebay if they have one,or buy one from your local bobcat dealer....
OldMachinist
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The wiring diagram only shows a couple of heavy red wires. One from the alternator large terminal to the starter and one from the same terminal back into the harness.
Thx, OldMachinist. That's good information. The heavy red wire I already connected to the alternator must be the one from connector C110 term 1 back to the large post on the alternator. The one still hanging might be from the same post on the alternator to the starter. I'll do some measuring with my MM tonight to confirm.
I suddenly got a feeling that it might be the one going to the starter. if this is true, it's a lot harder to hook it up.
I second the advise to not run the engine like that. Even though it may not feel like it is getting warm, it really is. The thickness between the underside of the head to the water passages isn't that big, heat will build up faster than you may expect as you can't feel it as it takes time to warm it's way through and outwards. No sense damaging it because of something so simple.
When i do a test like that, i run it no more than about 10 seconds, not at any high seed either.
It will take time to purge the air, depending on how many lines you removed.
Tazza, Thx. I agree with your way of thinking. Once I put everything including cooling system (going to use Evans waterless coolant) together, I'll start purging the air in it. I hope at least it will let me move it out of the garage soon after I start it, otherwise I have to hook up some kind of exhaust system to the outside while it's beening primed and purged.
Confirmed that the hanging heavy gauge red wire goes to the starter. Glad that I did not put everything together especially the radiator. Only need to take off the alternator to gain access.
I think spinning the hydraulic pump without having first primed the pump with oil and having no oil going thru them while spinning was a very foolish thing to do , I would think no doubt it has shortened it's life --if you wanted to hear it run before hooking everything up you should have run it on the ground before putting it in the machine -----but that is just me
Thx for the concern. The engine test run was done with out the coolant, but with the hydraulic fluid reservoir fully filled. What do you mean to prime the pump, how?
Quote " I did not cap the lines (return line to the reservoir, filter mounting plate etc. ). I did cover them with layers of cloth and bond with rubber bands. So, except the fluid in the cylinders, most of the lines and new filter are probably empty. " ------------------after reading your post above it sounded to me you ran it without fluid , I just I can't really make any sense out your post ====good luck
