Hello all, I am looking for an answer about the plungers in this injection pump. I bought new plungers and installed them and am finding one is not moving as freely as the rest are. It’s a 4 cylinder Kubota KX121-3. The old plungers were pretty free to move which I expect from continuous use over time. The new ones are much more tighter but I have one that seems to be getting stuck much more then the other three. my question is , will the plungers get freed up from the compression or it there going to be an issue even getting it to move?
They should have been freed up before installation.. They are packaged and shipped in heavy oil..so a good cleaning in a solvent tank is required.. I would expect the problem to get worse..especially if u didn’t torque the dv holders..
Thanks for the opinion. Yes they were oiled up when I received them but not too much. I noticed before I installed them they were pretty easy to operate. There is only one that seems to be binding up if I tighten down the top valve. I’ll try cleaning it in solvent and see how it works.
How freely should the plungers move in the once they are in?
U hafta make sure the barrel is squarely seated on its locating pin.. if u missed it, u probably sheared it..
The pump is not in the engine. The plungers are installed correctly but one seems to be binding up and not moving freely. I don’t want to reinstall the pump until I’m sure the plungers are in and working in their movement correctly. I just need to know whether or not the plungers are suppose to be freely moving and not binding. Thank you.
That looks like AI/spammer text.
U need to take the barrel out and hand lap them together..
The plungers are installed correctly and the pump is not in the engine. I could not have sheared anything off because again it’s out of the engine. I have replaced all 4 plungers but one seems to be binding up as if stuck. I’m not going to install the pump back into the engine until I’m sure plungers are all functioning properly. This is why I am asking more experienced people like your selfs. Yes I removed all the plungers. I there was only one that wasn’t moving freely so I switched barrels and now they all work. I’m assuming these plungers are all made individually and not as a set. Since they were all new I didn’t think switching barrels would be an issue as long as they all operated freely. I now have them working and the rack slides with ease. Now on to the next step. I do appreciate all the responses and thank you all.
Not an AI / spammer
the kubota parts online post was spam. As far as I know, you never switch fuel injection parts, they are mated.
Yes I see where you think it was spam. These parts are all the same parts I’m sure made by the same machine so I don’t see a problem with interchanging barrels and plungers. Especially bring new. I would not do that if they were worked. But there did seem to be a difference from one plunger and the other three barrels. Seems maybe the manufacturer need to calibrate their machines