Pralhad Birdi
Well-Known Member
Pilot pressure at the pilot pressure port just about the pilot relief valve.
Makes sense. Any chance anyone would have a copy of the relevant pages in the manual?Pump pressure is how big of a rock you can move. pump flow or volume is how fast you move it. Flow of pumps should decrease as engine feels a load. The prv valve is controlled by computer and it when working properly changes pilot oil pressure going to pump regulators to destroke pumps. In service manual there's theory and operation section which would explain it better. Get a book or download one. Understand the theory then test valve and report back.
Thanks, I’ll check that and revert.Hi,
Did you check the pilot pump delivery pressure at the pilot manifold pressure port near the pilot relief valve ?
If you didn't check, place the machine on to power mode 3 using monitor pannel power mode selection button and place the engine speed dial to position 10. Turn OFF the AEC switch from the monitor pannel. Bring the hydraulic oil temperature to 50 - 60 celcius by stalling implements several times.
Now check the pilot pump delivery pressure at the pilot manifold pressure port. It should be 500 ± 30 psi.
As you said, if the power looses after working some time then check the pilot pump pressure at that time also as i mentioned above. Because sometimes if the pilot pump is bad it will looses its delivery pressure when temperature raises.
That’s certainly true. The only issue is that as the machine carries on working, we have to bump up the throttle more and more to get a consistent power output. So I’m worried about engine/pump wear from running at very high rpms for extended periods.Seems like an awful lotta work when u can bump the throttle and “fix” the problem..lol
Absolutely brilliant. So that would go on in place of the PRV solenoid? And would tightening the bolt increase or decrease main pump pressure?My dad years ago made a plate with a bolt for adjustment to set pump control on a 320 that ECM was bad and customer was tight on funds. It was sort of slow but kept rpms up.
I’ve checked the pilot pump pressure, and it’s about 250psi at high idle. Does this indicate an issue with the charge pump?Hi,
Did you check the pilot pump delivery pressure at the pilot manifold pressure port near the pilot relief valve ?
If you didn't check, place the machine on to power mode 3 using monitor pannel power mode selection button and place the engine speed dial to position 10. Turn OFF the AEC switch from the monitor pannel. Bring the hydraulic oil temperature to 50 - 60 celcius by stalling implements several times.
Now check the pilot pump delivery pressure at the pilot manifold pressure port. It should be 500 ± 30 psi.
As you said, if the power looses after working some time then check the pilot pump pressure at that time also as i mentioned above. Because sometimes if the pilot pump is bad it will looses its delivery pressure when temperature raises.
Hi,I’ve checked the pilot pump pressure, and it’s about 250psi at high idle. Does this indicate an issue with the charge pump?
If you can, remove the pilot pump relief valve and disassemble it and see wheather is it good in condition. If the pilot relief valve is faulty or debries stuck in it, then sometimes it will open before the system pressure rises to its intended pressure limit.I’ve tried adjusting the pilot relief valve, but there’s no difference in pressure even if I screw it all the way in.
I disassembled the valve, but couldn’t find anything especially untoward. Would you have an exploded view of the same, just so I can check all the components are there and arranged properly?If you can, remove the pilot pump relief valve and disassemble it and see wheather is it good in condition. If the pilot relief valve is faulty or debries stuck in it, then sometimes it will open before the system pressure rises to its intended pressure limit.