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CAT 345C Excessive vibration

Tom2146

Member
Joined
Sep 2, 2022
Messages
9
Location
Wildomar, CA
I have a CAT 345C Excavator (S/N PJW02374) with some violent vibration issues when the hydraulics are engaged.
Machine recently blew a large hydraulic hose while on a steep slope and managed to dump all, or atleast 50+ gallons of hydraulic oil.
Other technician replaced the hose but did not re-fill the hydraulics before the operator decided to jump in and run the machine.
Hydraulics were slow and machine began to violent shake. The technician proceeded to add only 10 gallons of oil before he decided to track the machine down the hill and park it. Since then, the hydraulics have been completely re-filled, air was bled as best they could from the lines and they are still having violent shaking issues and very slow hydraulic movement from the Stick, Boom, Bucket, and Tracks. Swing is fine.
New hydraulic filters all around, new oil, and the main relief valve was cleaned by the other mechanic.
Any ideas of what it could be, before I tackle this machine later this week?20230128_062905.jpg
 

ahart

Senior Member
Joined
Nov 7, 2020
Messages
858
Location
Indiana
I’d be looking at the main pump. I had a 374D with those symptoms and it had one of the plungers in the pump explode and send brass out the case drain. The vibration you’re feeling could be the lack of flow out of the damaged plunger in the pump. Being as the swing is fine, I’d think your issue would be in the drive pump as the swing runs on the idler pump.
 

Tom2146

Member
Joined
Sep 2, 2022
Messages
9
Location
Wildomar, CA
would i perform a flow test or test for pressure at some test point to verify? or should i just open up the pump and visually inspect for damage?

The operators managed to track it down hill and fully extend the Stick, so there was pressure of some kind, but they said the entire machine was shaking violently.
 

Shimmy1

Senior Member
Joined
Aug 14, 2014
Messages
4,397
Location
North Dakota
???
Serious about what
Please don't take this the wrong way, but.....

You have an operator that fires up a machine with a probably $40k hydraulic pump with no oil in the system, who then proceeds to barely put enough oil back in to cover the inlet screen, and then stretch the machine out, which probably takes more than the 10 gallons of oil they added to the tank.

And you're asking if you should "tear into the hydraulic pump".

The answer is no, no you should not. IMHO.

The FIRST thing you should do, it take an oil sample, and make sure you're not pumping shrapnel all around in a hydraulic system. Then maybe there might be a few more things to check.
 

Tom2146

Member
Joined
Sep 2, 2022
Messages
9
Location
Wildomar, CA
Please don't take this the wrong way, but.....

You have an operator that fires up a machine with a probably $40k hydraulic pump with no oil in the system, who then proceeds to barely put enough oil back in to cover the inlet screen, and then stretch the machine out, which probably takes more than the 10 gallons of oil they added to the tank.

And you're asking if you should "tear into the hydraulic pump".

The answer is no, no you should not. IMHO.

The FIRST thing you should do, it take an oil sample, and make sure you're not pumping shrapnel all around in a hydraulic system. Then maybe there might be a few more things to check.
I'm open to suggestions. I'm just trying to get a head start on this thing before I actually see it for myself.
I've only experienced this symptom with air pockets in the past, so that's going to be my first guess.
 

Tom2146

Member
Joined
Sep 2, 2022
Messages
9
Location
Wildomar, CA
I'm open to suggestions. I'm just trying to get a head start on this thing before I actually see it for myself.
I've only experienced this symptom with air pockets in the past, so that's going to be my first guess.
Oil sample was sent out, just waiting for results to come back.
The other mechanic mentioned that the oil looked "ok", but he didn't cut open any of the filters he changed out
 

ahart

Senior Member
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Nov 7, 2020
Messages
858
Location
Indiana
Don’t let this get out of hand, put some good liquid filled mechanical gauges on both pump outlet test ports and see how the needles behave first. If it’s a broken plunger, you’ll be able to see that on the gauge. Get the filters back out of it and open them up and see what’s there. Check the tank for debris, if you’ve sent it through the system, it’s going to get pricey.
 

Tom2146

Member
Joined
Sep 2, 2022
Messages
9
Location
Wildomar, CA
Excuse the late replies, been busy with other equipment this week.
I didnt get a chance to pull the return filters, but i did pull the 2 Case drain and 1 pilot oil filter.

photos are from case drain number 1, directly off the pump.

We work on natural aggregate and material handling, but it looks like we are now in the Gold Mining business with these filters
1000038880.jpg1000038873.jpg1000038874.jpg1000038879.jpg
 

Tom2146

Member
Joined
Sep 2, 2022
Messages
9
Location
Wildomar, CA
Other mechanic forgot to put a lock out tag and he was actually on his way to get oil. Operator just assumed the machine was good, and started it up.

Worst part is that this pump was brand new from 2 years ago.
 

Tom2146

Member
Joined
Sep 2, 2022
Messages
9
Location
Wildomar, CA
I think your biggest problem now is that more of that sh1t you found in the filter is going to be everywhere else in the system. Start investigating the availability of a dialysis machine would be my suggestion, because that hydraulic system is surely going to need it - and probably more than once.
I'm hoping the oil sample comes back with only brass material and nothing else.
When I remove the pump next week, I'll be able to inspect a lot more and I'll Have to look into A Dialysis Machine.

I'm not too familiar with those machines or if anybody offers those services near me in southern California.
 

Shimmy1

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Messages
4,397
Location
North Dakota
I'm hoping the oil sample comes back with only brass material and nothing else.
When I remove the pump next week, I'll be able to inspect a lot more and I'll Have to look into A Dialysis Machine.

I'm not too familiar with those machines or if anybody offers those services near me in southern California.
At this point, I'm not sure what an oil sample shows really matters at all.
 

Nige

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Jun 22, 2011
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29,855
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G..G..G..Granville.........!! Fetch your cloth.
I'm not too familiar with those machines or if anybody offers those services near me in southern California.
Start with your local Cat dealer would be my first thought. If that system doesn’t get properly cleaned out you could be in for a world of hurt. Metallic or non-metallic debris it’ll tear stuff up just the same way.
 

ahart

Senior Member
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Nov 7, 2020
Messages
858
Location
Indiana
Once you get everything back together, filters need to be replaced with clean out filters and samples taken until particle numbers are within the acceptable range. After the samples come back good, you can switch back to regular filters. This is just forward thinking as you are nowhere near ready for this yet. Here’s a chart to help identify the proper filters.
image002.png
 
Last edited:

Nige

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G..G..G..Granville.........!! Fetch your cloth.
The problem you are facing is that if the system is not cleaned out correctly/adequately at the first time of asking you could end up with a bill of anything up to $250k for repairs (I'm considering cylinders, control valves, swivel, even travel motors here) where a machine the size of a 345 is concerned. The challenge you are facing is how to avoid dropping megabucks on repair work, and that is going to need a clear plan of action put in place regarding how to attack the problem before a wrench is even laid on the machine. This is one of those situations where any mistakes in the repair process can prove to be VERY expensive. My 2c. YMMV.
 
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