I am attempting to bring a 1993 L555 back to life. Both hydrostatic pumps and both motors have been rebuilt. I am now in the process of putting everything back together. Once I get it all assembled I will fill with new fluid but what about the filters? Should I put new filters on now also or wait until the pumps and motors are broken in? Are Wix filters good enough? Are they better or worse than filters from the NH parts store? Should I do anything to the chain case besides refill with fluid? I already cleaned the magnets and suction screen but I haven't attempted to clean the chain cases. Anything special need to be done to prime the hydraulic system and/or the diesel fuel system? I also replaced the rear axle seals and outer bearings since they were leaking (baling twine). Thanks, Brett
You are using an out of date browser. It may not display this or other websites correctly.
You should upgrade or use an alternative browser.
You should upgrade or use an alternative browser.
Help Support SkidSteer Forum:
antfarmer2
Well-known member
- Joined
- Oct 28, 2013
- Messages
- 2,801
I would flush out all the lines first and put new filters in then replace filters after a bit mop out the chain case with rags and clean good you really want to get all the metal out or will be doing it again
Well I definitely don't want to do it again --$$$$$$. How would I go about flushing all the lines? Do you mean the hoses including boom and bucket hoses? How about the cylinders? The oil looked pretty good when I drained it. Only very few little metal shavings in the suction filter magnet. Thanks for the help.I would flush out all the lines first and put new filters in then replace filters after a bit mop out the chain case with rags and clean good you really want to get all the metal out or will be doing it again
antfarmer2
Well-known member
- Joined
- Oct 28, 2013
- Messages
- 2,801
I have never done it but think Tazza has on a bobcat should be close try emailing himWell I definitely don't want to do it again --$$$$$$. How would I go about flushing all the lines? Do you mean the hoses including boom and bucket hoses? How about the cylinders? The oil looked pretty good when I drained it. Only very few little metal shavings in the suction filter magnet. Thanks for the help.
If you had a catastrophic failure of the hydro pumps and motors, you need to flush everything that came in contact with the oil. Disassemble all cylinders and clean. Flush solvent through hoses and lines. Disassemble control valve and clean. Remove axles and clean housings and chain cases. Disassemble hyd pump and reseal. NH recommends replacing the oil cooler because they are impossible to clean completely. Install new filters and use NH filters........ I have reused the oil coolers but spent a lot of time flushing them. You do need to disassemble the cylinders and flush the lines to get the old oil out. A little attention to the details now may save you thousands of dollars down the road.I have never done it but think Tazza has on a bobcat should be close try emailing him
I don't think I had a catastrophic failure. It just moved jumpy and jerky. The seller told me he thought it was a wheel bearing sticking. I didn't know better and bought it. The boom and bucket worked great but soon I realized that there was more going on than a bad wheel bearing. When I first started digging into this machine the chain case magnets had some filings but not bad and the suction filter screen didn't have much at all. Actually the hyd fluid looked pretty good. Both pumps and both motors were removed by me and professionally rebuilt. The shop said they were just worn, nothing said about a catastrophic failure. I looked at all the parts when they were disassembled. Everything looked really good but they were beyond tolerances. Do you still think I need to disassemble the whole machine and clean everything? I have already spent around the max value of this machine. I really don't want to do all that but I will if it is absolutely necessary. Thanks.If you had a catastrophic failure of the hydro pumps and motors, you need to flush everything that came in contact with the oil. Disassemble all cylinders and clean. Flush solvent through hoses and lines. Disassemble control valve and clean. Remove axles and clean housings and chain cases. Disassemble hyd pump and reseal. NH recommends replacing the oil cooler because they are impossible to clean completely. Install new filters and use NH filters........ I have reused the oil coolers but spent a lot of time flushing them. You do need to disassemble the cylinders and flush the lines to get the old oil out. A little attention to the details now may save you thousands of dollars down the road.
Motors and pumps don't "break in" they should be perfectally clean when assembled, so there are no metal particles to pick up later, unlike an engine that wears in.I don't think I had a catastrophic failure. It just moved jumpy and jerky. The seller told me he thought it was a wheel bearing sticking. I didn't know better and bought it. The boom and bucket worked great but soon I realized that there was more going on than a bad wheel bearing. When I first started digging into this machine the chain case magnets had some filings but not bad and the suction filter screen didn't have much at all. Actually the hyd fluid looked pretty good. Both pumps and both motors were removed by me and professionally rebuilt. The shop said they were just worn, nothing said about a catastrophic failure. I looked at all the parts when they were disassembled. Everything looked really good but they were beyond tolerances. Do you still think I need to disassemble the whole machine and clean everything? I have already spent around the max value of this machine. I really don't want to do all that but I will if it is absolutely necessary. Thanks.
Replace the filters before adding oil.
As already mentioned, if there was a failure or any doubt, clean ALL the lines and cylinders out before filling with oil. You then know it is good to go.
One thing i did to primee my machines after a rebuild like that is to operate the pedals while extending and retracting the hydraulic cylinders by hand. This will draw oil in, through the pump and oil cooler. Then you know it is not starting dry.
Good idea on the priming. Can I do that with just the bucket cylinder or should I do it with all 3? I'll replace the filters before adding oil. Then the manual calls for replacing the filters again after 25 hours. Does that sound right?Motors and pumps don't "break in" they should be perfectally clean when assembled, so there are no metal particles to pick up later, unlike an engine that wears in.
Replace the filters before adding oil.
As already mentioned, if there was a failure or any doubt, clean ALL the lines and cylinders out before filling with oil. You then know it is good to go.
One thing i did to primee my machines after a rebuild like that is to operate the pedals while extending and retracting the hydraulic cylinders by hand. This will draw oil in, through the pump and oil cooler. Then you know it is not starting dry.
I can't see why you can't do it with just the tilt ram. You just want something to draw oil through the pump. Ideally a vacuum pump on a hydraulic line would pull oil through, but not everyone has one to hook up. You don't want to use the household vacuum cleaner and then incur the wife's wraith when you fill it with oil.Good idea on the priming. Can I do that with just the bucket cylinder or should I do it with all 3? I'll replace the filters before adding oil. Then the manual calls for replacing the filters again after 25 hours. Does that sound right?
I have never had issues with just using a cylinder to draw oil into the pumps though. Even if you disconnect the fuel shut off solenoid and crank the engine to get oil moving before it gets up to speed.