hydraulic valve problem?

[Breezeblock]

I've had a look at the diagram and from what you describe it looks like the 3cc section of the pump is bypassing the valve limits it to 120 bar when its activated bringing in both pumps to increase the flow and 170 bar when its not so you definitely need to start by putting a gauge on it

[dig-dug-dan]

I've had a look at the diagram and from what you describe it looks like the 3cc section of the pump is bypassing the valve limits it to 120 bar when its activated bringing in both pumps to increase the flow and 170 bar when its not so you definitely need to start by putting a gauge on it

 

Its a tandem pump, but one side is running the conveyor, or so I thought.

there is a test port or two, so will get a tester and see.

[openspaceman]

I've had a look at the diagram and from what you describe it looks like the 3cc section of the pump is bypassing the valve limits it to 120 bar when its activated bringing in both pumps to increase the flow and 170 bar when its not so you definitely need to start by putting a gauge on it

 

I don't quite understand that but think you are describing a power or torque limiting protection.

 

Both pumps run the motors when the going is easy but if the load gets high one pump bypasses to tank whilst the other pump is able to run at higher pressure but only its flow. Power being flow times pressure.

[dig-dug-dan]

Now I am confused! The tandem pumo I have has two pipes coming out the side, a smaller one near the front, and a larger one at the back. The smaller one is connected to the conveyor side, which is operated by a lever, bolted on to a central block that has a couple of pressure valves in it, and i presume the solenoid for the higher speed, on the other side is the two valves for the tracks.

are you saying that in high speed, it takes oil from both outlets of the pump, and low speed only one outlet?

[scbk]

are you saying that in high speed, it takes oil from both outlets of the pump, and low speed only one outlet?

 

The hydraulics are obviously modified on the crusher machine you have, but on the standard TCP HT500 dumper, the small pump does low speed, and both pumps combined do high speed

 

"1.3 Hydraulics

Refer to the Hydraulic Schematic drawing in Section

7.22 Carrier Hydraulics Mk4 –2006 Drg 1599.

The diesel engine drives a hydraulic pump coupled

to its shaft. This pump provides two outputs:

• a 3 cc per rev, low flow, high pressure output for

low speed and general use and

• an 8 cc boost output.

These are combined to provide an 11 cc/rev high

flow, high pressure boost drive for the high speed

track drive."

[openspaceman]

Now I am confused! The tandem pumo I have has two pipes coming out the side, a smaller one near the front, and a larger one at the back. The smaller one is connected to the conveyor side, which is operated by a lever, bolted on to a central block that has a couple of pressure valves in it, and i presume the solenoid for the higher speed, on the other side is the two valves for the tracks.

are you saying that in high speed, it takes oil from both outlets of the pump, and low speed only one outlet?

 

 

Yes when travelling but presumably the conveyor is not used when travelling?

[dig-dug-dan]

Correct. But I have high speed travel, its low speed I am missing, cusher works so must be oil flow ok

[cornish wood burner]

Assuming you have a dedicated relief valve in the tracking circuit it might be worth checking that is not jammed partially open by a piece of debris.

[Breezeblock]

the first thing you have got to do is get a gauge on it its total guesswork until you get facts and figures

[openspaceman]

Correct. But I have high speed travel, its low speed I am missing, cusher works so must be oil flow ok

 

So oil from both pumps is getting to the track motors at all times?