pump output psi setting?

[763-NJ]

I just got my machine running and need to set the psi. I have a 1998. 763F. I have a gauge in the outlet of the pump. Thank.

 

[763-NJ]

Its at 400psi at idle and around 1000psi when lowering the boom. Turning the main relief valve does not change my psi at all.

 

[OldMachinist]

Its at 400psi at idle and around 1000psi when lowering the boom. Turning the main relief valve does not change my psi at all.

Service manual says 3000-3050 psi at the quick couplers at full throttle.

 

[Tazza]

Service manual says 3000-3050 psi at the quick couplers at full throttle.

That pressure is very low, it sounds like either you have a broken spring/something stuck in the relief or a bad pump.

 

[763-NJ]

That pressure is very low, it sounds like either you have a broken spring/something stuck in the relief or a bad pump.

The unit works good. Haven't tried to lift anything heavy yet. When I bottom or run out of travel it goes to 3,000psi. I adjusted main relief to 3,000 at travel end, but still at 400psi at idle. I do have a new pump on it. And I rebuilt the hydraulic block and it all looked good.

 

[gearbox]

The unit works good. Haven't tried to lift anything heavy yet. When I bottom or run out of travel it goes to 3,000psi. I adjusted main relief to 3,000 at travel end, but still at 400psi at idle. I do have a new pump on it. And I rebuilt the hydraulic block and it all looked good.

I hope I don't double post this I lost my last post . Your oil needs to be warm I think your 400 and 1000 readings will drop when warmed up . you are forcing oil thru your return filter and when you drop your boom you are pushing alot of oil thru that filter .Gearbox

 

[Tazza]

I hope I don't double post this I lost my last post . Your oil needs to be warm I think your 400 and 1000 readings will drop when warmed up . you are forcing oil thru your return filter and when you drop your boom you are pushing alot of oil thru that filter .Gearbox

As you say it spikes when you bottom out, i wonder if you are measiring it correctly. Put a gauge on your aux coupler then operate the aux hydraulics, it should give you around the 3,000 psi reading you got earlier.
Without anything hooked up or engaged, there will be some pressure there, just not the full 3000

 

[763-NJ]

As you say it spikes when you bottom out, i wonder if you are measiring it correctly. Put a gauge on your aux coupler then operate the aux hydraulics, it should give you around the 3,000 psi reading you got earlier.
Without anything hooked up or engaged, there will be some pressure there, just not the full 3000

I think your right, I need to get it done threw threw the aux. Coupler.

 

[7LBSSMALLIE]

I think your right, I need to get it done threw threw the aux. Coupler.

NO main reliie needs to be checked on a direct pump test and direct pump test only,

 

[7LBSSMALLIE]

NO main reliie needs to be checked on a direct pump test and direct pump test only,

hey tazz if you need further quidance on this just ask be glad to give a dissertation on pump checkining, but I have been known to give a little too mich info.

 

[Bobcatdan]

hey tazz if you need further quidance on this just ask be glad to give a dissertation on pump checkining, but I have been known to give a little too mich info.

You can't test relief pressure at idle. Unit needs to be full speed. All you care about that stall pressure is 3000 psi. Any other pressure doesn't mean anything as it is going to vary depending on load.

 

[7LBSSMALLIE]

You can't test relief pressure at idle. Unit needs to be full speed. All you care about that stall pressure is 3000 psi. Any other pressure doesn't mean anything as it is going to vary depending on load.

all correct, warm oil full rpm direct pump check. cut corners = replacing 800.00$ parts