Hydraulic pressure ?

[dig-dug-dan]

 

Here you can see the ceetop, center two pipes go to the ram, one comes in from pump, the other goes to the track valves. Not visible is the test port which is in the silver port block

[dig-dug-dan]

 

Here you can see the ceetop, center two pipes go to the ram, one comes in from pump, the other goes to the track valves. Not visible is the test port which is in the silver port block.

Today i finally put a tester on. I am getting 105 bar, which is what i am supposed to be getting. I tried replacing the ram with a spare, it made no difference, so surely now it must be the pump??

[dumper]

105 bar seems low 

[dig-dug-dan]

7 hours ago, dumper said:

105 bar seems low 

Its what the manufacturer told me was correct

[dig-dug-dan]

Update

 

Tested pressures. Ok. Compared to another machine. I brought an ifared thermometer, and tested various components. Pump was showing 60d degrees c, most other components between 25 and 40.

Tested ankther machine, could only bet 40 degrees c from the pump.

Therefore can i conclude something wrong inside the pump causing the heat build up???

[donnk]

you need to test pressure when it exhibits the fault if you can. But It looks like swopping the pump is the crack.

[monkeybusiness]

Can’t you swap the pump (and if not the issue then other components) from the good machine to isolate the fault if you have more than one?

[openspaceman]

40 minutes ago, monkeybusiness said:

Can’t you swap the pump (and if not the issue then other components) from the good machine to isolate the fault if you have more than one?

It should be easier than that and  not worth the loss of oil nor risk of cross contamination.

 

It may well be that the hotter pump is showing oil being recirculated within the pump but I wouldn't buy a replacement without some simple tests.

 

Normally the pump is protected by a pressure relief valve, if a service is stalled then the pressure relief valve should blow off and return oil to tank. If the pump fails to reach pressure then the relief valve does npot open, does not return oil to tank and the oil recirculates in the pump, possibly making it warmer.

 

The first indication of a pump failing is when it only reaches relief pressure at a higher rpm, so under normal working the pressure rises to relief pressure (say 2000psi) and holds that pressure as the relief valve dumps excess to tank, with a worn pump the pressure rises slowly with rpm until finally the relief pressure is reached and then is held steady as relief opens and the excess pressure is dumped. This dynamic testing is what the device @aspenarb posted does but an inference can be made with just a pressure gauge.

[dig-dug-dan]

23 minutes ago, openspaceman said:

It should be easier than that and  not worth the loss of oil nor risk of cross contamination.

 

It may well be that the hotter pump is showing oil being recirculated within the pump but I wouldn't buy a replacement without some simple tests.

 

Normally the pump is protected by a pressure relief valve, if a service is stalled then the pressure relief valve should blow off and return oil to tank. If the pump fails to reach pressure then the relief valve does npot open, does not return oil to tank and the oil recirculates in the pump, possibly making it warmer.

 

The first indication of a pump failing is when it only reaches relief pressure at a higher rpm, so under normal working the pressure rises to relief pressure (say 2000psi) and holds that pressure as the relief valve dumps excess to tank, with a worn pump the pressure rises slowly with rpm until finally the relief pressure is reached and then is held steady as relief opens and the excess pressure is dumped. This dynamic testing is what the device @aspenarb posted does but an inference can be made with just a pressure gauge.

I think i understand you, in fact i put a pressure gauge on when the stalling occcurs, amd the needle on the gauge went up much higher than the 105bar, and slowly came down, but the ram never changed direction like it should do.

I have changed the pressure relief valve already, to no avail.

I also have three new pumps in stock. They tend to leak after a while and end up with a hairline crack in them. Common fault, but never had one fail internally.

Watch this space

[dig-dug-dan]

Pump changed today. Success! Must be an internal fault. So relieved!

Now to get the pump repaired. Thanks for all the advice. Going to get one of those flow meters sometime if i can find one