I picked up a used Cat 303.5C CR with 1100 hrs. Serial number DMY00793. This is my first piece of equipment. The machine will swing in both directions, but doesn't have any power. Its impossible to even push a small amount of dirt to back fill. I put a pressure gauge on TP1 and got the following results: Main relief valve is at 3,650 PSI Left and right swing is at 3,600 PSI. The boom, stick, bucket, thumb and blade are at 3,600 PSI. Im at a bit if a loss given that the pressures are that high. Any help would be greatly appreciated.
mine does't have a lot of power for that purpose and the book says ( do not use the swing for back filling ) to avoid damaging machine.
Good day You appear to have enough pressure to create the correct swing force, I suggest you check for creep in both directions if thats good I guess Billrog is steering you in the correct direction. Kind regards Uffex
Spec for main relief valve (adjustable) - 3400-3700psi Spec for swing relief valve (non-adjustable) - 3050-3500psi No offence intended but I've seen "operators" shown the door for using the swing function on an excavator for backfilling. It shortens the life of the pins & bushes in the linkage significantly, no matter how well greased the pins are. Do you have an Operation & Maintenance Manual for it.?
Thanks for replying. I do have the manual for it. I'll check to see if it has any creep. Like you guys had mentioned it might not be that powerful by design. This in the first excavator I have run, its always been backhoes and they have rams to push the boom left and right.
I am afraid Nige comment is correct most if not all manufacturers frown on side sweeping it is bad for the machine as it is not designed to absorb side loading, however having observed many operators it is a habit or technique used by many. I guess its down to judgement of the man in the seat as to what can cause damage and those risks involved. Kind regards Uffex
Definitely dont want to end up looking like that guy. Given that I own the machine and I would have to fund all repairs I think I will limit the amount of side loading. As it sits it wont be a problem because it doesn't have the power to push even a small amount of dirt to the side. Thanks for the advice.
No compact excavator ive owned or been on has ever been able to move more than a tiny pile like 1ft by 2ft by 2ft pile of dirt with the swing.
Ok, i was able to park it on an incline and test for creep, I loaded the 24" bucket with dirt (331 lbs according to the manual) fully extended the boom and turned it off. It didnt move at all over the 3 min. When i went to swing back up towards the front of the machine (up hill) fully extended it was barely able to do it. I was thinking about swinging by Cat and see if i can sit in the seat of one of their rentals to get a feel of what another one is able to do.
Good day The test you made illustrates that the negative brake is functioning, if you have full pressure as you begin to slew against the incline would suggest the machine is up to standard. Kind regards Uffex
This also illustrates how important it is to make a pad for the excavator when working on any slope to that the machine sits level no matter what the slope is doing. The smaller the machine, the more ciritical it is to have it as close to being level as possible while working. You have one of the smallest machines out there - QED.
Steve, did you reach out to the local Cat dealer? We have the ability to look in to past service letters from Cat, other dealers complaining of a similar concern, etc. Just because it was a used unit doesn't mean the Dealer won't support you after the fact... if they can't help you - shoot me a reply and I will look into it for you