Replaced the hydraulic pump, fresh fluid, and also the slew motor. When i use both tracks at the same time it will stall my motor out. Using just 1 track at a time has no effect on the motors operation. From my understanding P1 supplies 1 track and P2 supplies another. Just from what i have gathered it would seem like its over pressurizing due to #1 its blown a line in the short time I tested it and #2 some connections were leaking that didnt seem right. Im positive its nothing engine performance related. Any help would be appreciated. My current thought is main relief valve stuck, solenoid not in operation. Person i purchased this mini from has rigged some things but over function of the mini is perfect aside from this problem. I can move the bucket, arm, slew without effecting the motors operation. Thanks again.
Try and get some test gauges on the P1 and P2 pump lines and check that the main relief has not been adjusted and set too high by the previous owners. Once the main reliefs are checked and set then you can look at the pumps horsepower adjustment if needed. Try to hold onto the old pump for spare parts like the horsepower control springs.
Ok i tried logging into this site multiple times to message you back. I will ordering some gauges and testing the pumps here soon. Thank you.
Your welcome. I have also had problems occasionally getting and staying connected to this site but whatever it was looks like its been resolved now. I just wasn't sure if it was my internet connection or the site that was having issues.
So im getting less than 1000 psi on one track. Im getting this reading while the tracks are off the ground. Will it only achieve the target psi under load? Or it should operate at that psi regardless? Seems strange when i do put it under a load it will reach around 2800 psi. I just bought brand new main reliefs and still getting same symptoms. EVERYTHING works great until i command both tracks in unison.
If the engine is not maintaining its engine maximum rpm when both tracks are stalled up to maximum specified pressure then either the pump is not regulating off to the correct flow or the Engine is not maintaining enough power, possibly fuel or governor issue or even a collapsing air intake. I will do some research over the next couple of days and get back to you. In the meantime see if you can locate the hydraulic filter and replace it, try to cut open the old one and inspect it, also take an oil sample from the hydraulic tank and check it is clean with no signs of metal as a precaution. Kind regards
So i gave the set screw on the pump a half turn in and that did it... Its not perfect and i think i need to make more adjustments. I have replaced all the filters, and all new fluid. So this is what made the difference!
Im also only able to achieve 2000 PSI and the book calls for ~2800. I am assuming adjustment of the main reliefs and the the pump are still needed to get to where i need to be.
Nice work on the pump adjustment!. Winding the horsepower set screw in would usually increase the pumps horsepower setting, did you mean you wound this set screw out instead of in by chance?. Hopefully like you said it may just need some tweaking of the main relief and your all set to go again. The pumps volumetric efficiency losses cannot be directly measured as the pump suction port also floods the housing I believe. I have noticed a number of KYB and Nachi make pumps which have an almost identical pump model code to the OEM, and have different horsepower springs, shims and power shift pistons giving them a a completely different power curve. If you have the old pump parts like the horsepower springs and shims then hold onto them just in case you cant get the pump to regulate back to where you need it too. Best regards
Ok so she is running much better. I just wanna state i have done A LOT of work to this girl. So i noticed something really strange. When i curl the bucket to the max (inwards) i get a vibration in the valve body? ALSO when i leave the bucket in this position i cant move both tracks at the same time without getting the same vibration in the valve body. When i move the bucket out of this position i no longer get the vibrations and can freely move both tracks no issues. I am currently waiting on some G1/4 fittings to put on these lines to finish dialing in the peak pressures. I have only dialed in 1 leg and that is " R2 " which according to the service manual should be @ 2800 psi. Just trying to give you as much information as possible. And i ended up turning the horsepower screw in 2 full turns. Looking at my old pump, i got the set screw closer to where the old one is. Overall she seems really happy and im impressed with the power shes got!! Thank you again for your help. And you are correct the suction side of the pump is just flooded. I wanna say i received the same brand pump. Alibaba has came in clutch no joke.
looks like your back in business but I'm not sure what the issue would be with that bucket curl causing a vibration when curled in or when using the tracks with its curled in ? . It kind of sounds like when you curl the bucket in you don't have enough oil left in the tank for other operations ? Tricky one to isolate but I'm sure you will get to the bottom of it. All the best Kind regards