953c hydraulic pump

She broko..........

At least you’ve found it. I had a pump fail on a 963D, (axial pump) slipper plate failure. I was worried about where the debris had got to, but did a double oil and filter change with the new pump and never had any more problems.

Yes, I was actually relieved when I found it. I hate taking something apart and not finding anything wrong and having to dig deeper.

Do you think the debris was contained within the pump area?








?

Doesn’t look like there’s much fine debris, which is a plus.

JDirt said:

Yes, I was actually relieved when I found it. I hate taking something apart and not finding anything wrong and having to dig deeper.

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Did you happen to notice whether or not it was a Cat pump.? The failure mode is somewhat unusual, to say the least.

Thinking the same. Had something jammed the rotor?

ih100 said:

Thinking the same. Had something jammed the rotor?

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ih100 it does seem like a sudden urge to stop may of happened. I've never seen it happen mind you, but there was a Don't dead head a Pump rule back at the power plant. Most every hydraulic pump I ran into had a internal relief valve to prevent a hydraulic lock. It does look like the pump jammed. I suppose this is a cartridge exchange with no peeks inside.

From the photo of the shaft that pump would likely not be eligible for Core Credit against a Reman anyway.

I assume it's a cat pump, seems like the debris did not get out.
So far I have only found a new pump for $1566.
I'll disassemble my pump and take some pictures.

That doesn’t sound too bad a price. I think a new pump for a 63D was around £4000 fifteen years ago, direct from Cat Grimbergen

Agreed. I'm seeing $1625. There is no Reman option, quite likely because it's a vane-type pump.

Before you start up with your new pump i would do either of two things
1/ Back off your main relief valve a couple of turns to protect your new pump and then set your relief valve
2/ if you dont back off your relief valve at least hook a gauge and feather your controls and observe your pressure build to make sure it is in range
i have seen too many cowboys play with the relief settings over time, chasing more performance from there machine and not understanding what they are doing
Good Luck
Mark

Good advice, I will do just that, got my new pump from CAT this morning, just have to make time to put it in.

Got the old pump disassembled here's what it looked like

New pump is installed and working, pressure was 3100 psi, I turned the relief valve maybe a quarter turn, now it's 3800, thought maybe I should find the correct procedure for adjusting before I went any further. I'm not real sure about which part to turn, which is the jamb nut and which way to turn.

Spec is 3485 +/- 50psi.
There are two types of main relief valve. Please post a photo of the valve you have on your machine so we can see which type it is.

JDirt said:

Got the old pump disassembled here's what it looked like View attachment 243840

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I think there is some outfit on FleaBay that sells glue to fix that pump!

Just kidding, I agree getting the main pressure right is important. I might be tempted to disassemble the relief valve to make sure there isn't some crap in there that could cause it to not relieve correctly.

Here's the main relief valve
I did disassemble it before changing the pump, it was clean.

I'd like some confirmation but from what I can determine your relief valve is missing a locknut.
There are two settings on that valve, low & high.
The High setting, which should be done first, is made by loosening the locknut and using the arrowed adjuster, referred to as "B" in the procedure.
The Low setting is made by loosening the thin locknut (arrowed red) that I think is missing on your valve, and an allen key in the end of the spindle.
Complete procedure below.


Note: Always adjust the HIGH setting before adjusting the LOW setting.
1. Connect a 50000 kPa (7250 psi) pressure gauge to pressure tap (B).
2. With the engine at HIGH IDLE, raise the bucket to maximum height.
3. Hold the lift control lever in the RAISE position and observe the pressure gauge reading.
4. With the tilt control lever in the HOLD position, the main relief valve should be at the HIGH setting.
5. With the tilt control lever in the TILT BACK position, the main relief valve should be at the LOW setting.
6. The correct HIGH pressure setting of the main relief valve is 24000 ± 350 kPa (3480 ± 50 psi) at a flow of 130 ± 6 L/min (34 ± 1.6 US gpm).
7. The correct LOW pressure setting of the main relief valve is 21400 ± 350 kPa (3100 ± 50 psi) at a flow of 130 ± 6 L/min (34 ± 1.6 US gpm).
8. If an adjustment is needed, the HIGH setting should always be adjusted before the LOW setting. After adjusting the HIGH setting, the LOW setting can be adjusted.
9. The HIGH setting of the relief valve can be changed by turning large adjustment screw (B) . One quarter turn of adjustment screw (B) changes the pressure setting by 1512 kPa (220 psi).
10. The LOW setting of the relief valve can be changed by turning small adjustment screw (C) . One quarter turn of adjustment screw (C) changes the pressure setting by 755 kPa (110 psi).
11. Both screws turn clockwise in order to increase the pressure setting and both screws turn counterclockwise in order to decrease the pressure setting.