Please advise Main hydraulic pump coupling failed. Instead rebuilt hydraulic pump but the coupling failed in few hours. First the excavator machine's crawling speed in one direction got slow . The mechanic told to increase pump pressure by half a turn oprator tightened one and half thread from the pump . Oprator started the machine but no help . Machine blew up hydrulic boom seal and then the coupling broke . Please view pictures attached.
Looks like it has run a wile like that and you need to put a gauge in system and check pressure
Thank you for your reply. I will ask the mechanic to check the pressure. Will the excessive pressure effect the coupling?
Yes
As the excavator was crawling slow in one direction mechanic told oprator to tighten main pump pressure screw by one and half turn that might have increased the hydraulic pressure and the coupling failed. Thank you for your advice and guidance.
I don't want to come off as a jerk, but you need to hire someone who knows what he's doing. I know nothing of the machine that you are working on, but most hydraulic excavators work in the same manner. There isn't a main pump. One pump works half the functions and the other pump will work the other half. And then both will stroke up for added flow and pressure. There is only one relief valve in the system. It's a lot more complicated than I make it sound and it's more than I could coherently peck out on the phone to explain it better. There are numerous ways to screw this system up. Also if the pump was leaking fluid inside the flywheel housing with the coupler. That too can destroy the coupler. Again I don't want to come off as a know it all jerk. I want to help you and help you save money.
Looks like age got the coupling to me
Make and model of the machine is necessary for any specific types of information. Hour meter reading would also be a help.
Thank you everyone . Mechanic installed coupling, adjusted pressure machine swings and now crawlers. The problem now is that excavator doesn't have that much power in crawling uphill , The upper structure moves by itself when moving uphill. Mechanic says that its normal as its a mini excavator 4 ton machine.
Where's the rest of the coupling?
The plastic one broke
My excavator tends to swing towards the lower side without even touching the controls. What i want to say is "it automatically swings towards the side which is low when i am climbing up hill" Another problem is the crawling speed very slow and it completely stops climbing uphill . Yesterday i had to tow it up with my s.u.v to support it climbing uphill. Its old samsung rod controls wheel excavator . Its 4 ton 4 clynder samsung wheel excavator with mechanical linkages. Please advise. Thank you
4000 Hrs , 4 ton samsung wheel excavator with 4 clynder engine. It has mechanical linkages
@BigWrench55 My coupling also broke the 4 bolts connecting it to the pump. CAT323D There was hydraulic fluid inside the housing. Its 3 months old. We replaced it when we installed a recon engine. Not sure if the oil only started leaking after the coupling broke or if it was leaking beforehand. Its a piston pump (sbs120). I opened it and did not see anything visibly wrong. Was turning fine without stopping. I sent the pump away for testing. If the pump is working fine; what else could be the reason it broke. Stuck bypass valve maybe? Some say the coupler should be installed flush with the pump shaft. We installed it on the same place the previous one was. On some Youtube videos their was also not flush with the shaft.