Need Help Diagnosing Hydraulic Problem on a Crown Log Self-Loader

[scso1502]

Hello,

I'm helping a buddy work on a hydraulic issue with his Crown logging self-loader. The model of the loader might be a 25001, but that's unconfirmed. I've attached a picture of the loader.

The issue he has is the hydraulic lines and cylinders get very hot and it loses lifting power after about 30 minutes of loading logs. The other thing that is happening when the system gets hot is that the loader's turret wants to move to the right on its own while the operator is lifting the load. To comensate for this, the operator must apply left power on the turret to keep it from moving to the right, which further reduces the liftng power of the loading boom. I'm wondering is anyone can give us some help in identifying what the problem might be?

So far we've:

1. Replaced all 4 hydraulic oil filters

2. Drained and replaced the loader's hydraulic oil and replaced it to capacity with 50 gallons of new AW-32 hydraulic oil

3. Rebuilt a leaky boom extention cylinder that was bypassing and leaking-off causing it not to hold in the position it was left in

4. Replaced and/or tightened any the leaky hydraulic hoses and made sure there are no visible hydraulic system oil leaks

Doing the above definately improved things and gave the loader more power that lasted longer. The cylinder we rebuilt no longer drops from slowly bleeding off as it seems to be working well. However, we still can't get a full load of logs on the truck before the loader hydraulics get too hot and lose power to the poing we can't get logs high enought to drop them into the bunks.

The owner of the truck thinks the hydraulic oil is bypassing somewhere like at a relief valve that is out of adjustment or stuck partially open. The problem is he doesn't know exactly where to look for the problem. Having a schematic of the hydraulic system would help we don't have anything like that and can't find anythng online either. We may just need to trace out the hoses and see if we can find out where the problem might be, but if anyone has experienced something like this on a log loader, you thoughts on what the issue could be or if there are any adjustments that need to be made to resolve the isse, we would really appreciate the help.

Many thanks and take care,
Mike Vail
Stevensville, MT. USA

 

[Junkyard]

Get an infrared thermometer and once it starts acting up start taking temps on cylinders, valves, motors etc. The hotspot will more than likely be your issue, assuming it’s only one lol.

Based on your symptoms I’d say a relief valve is acting up and there’s a control or motor issue with the swing. You could even take temps starting from cold and see where it begins to build heat first.

 

[scso1502]

Excellent idea, I'll do that! Thanks Junkyard!

 

[Delmer]

The circuit relief valves and that section of the valve for the turret swing would be the first place to look with the infra red thermometer. On a cool morning.

 

[mekanik]

Something I would strongly recommend would be torquing both sets of rotation bearing bolts. I have seen them fail on 2 occasions. Fortunately the operator was not seriously injured either time.

 

[OregonBunch157]

Hello,

I'm helping a buddy work on a hydraulic issue with his Crown logging self-loader. The model of the loader might be a 25001, but that's unconfirmed. I've attached a picture of the loader.

The issue he has is the hydraulic lines and cylinders get very hot and it loses lifting power after about 30 minutes of loading logs. The other thing that is happening when the system gets hot is that the loader's turret wants to move to the right on its own while the operator is lifting the load. To comensate for this, the operator must apply left power on the turret to keep it from moving to the right, which further reduces the liftng power of the loading boom. I'm wondering is anyone can give us some help in identifying what the problem might be?

So far we've:

1. Replaced all 4 hydraulic oil filters

2. Drained and replaced the loader's hydraulic oil and replaced it to capacity with 50 gallons of new AW-32 hydraulic oil

3. Rebuilt a leaky boom extention cylinder that was bypassing and leaking-off causing it not to hold in the position it was left in

4. Replaced and/or tightened any the leaky hydraulic hoses and made sure there are no visible hydraulic system oil leaks

Doing the above definately improved things and gave the loader more power that lasted longer. The cylinder we rebuilt no longer drops from slowly bleeding off as it seems to be working well. However, we still can't get a full load of logs on the truck before the loader hydraulics get too hot and lose power to the poing we can't get logs high enought to drop them into the bunks.

The owner of the truck thinks the hydraulic oil is bypassing somewhere like at a relief valve that is out of adjustment or stuck partially open. The problem is he doesn't know exactly where to look for the problem. Having a schematic of the hydraulic system would help we don't have anything like that and can't find anythng online either. We may just need to trace out the hoses and see if we can find out where the problem might be, but if anyone has experienced something like this on a log loader, you thoughts on what the issue could be or if there are any adjustments that need to be made to resolve the isse, we would really appreciate the help.

Many thanks and take care,
Mike Vail
Stevensville, MT. USa

I had a Grizzly 215 that had a lot of these similar problems, it turned out to be one of the gate valves for the hydraulic oil going from the loader to the pump had broke and was turned partially inside which caused a restriction and caused it to get very hot. I replaced them with ball valves and it cured a lot of problems, was like a brand new machine.

 

[scso1502]

Thanks to everyone for your responses. It ended up that we had to pull the PTO pump and have it rebuilt. I was really surprised that this fixed the problem but it did. A local hydraulics shop replaced the guts of the pump and dialed it in. Very expensive for sure but in the end, the old loader now lifts like a beast and no longer overheats.

Thanks again everyone from Montana.

Happy Holidays,
Mike