I bought a cat 325L recently for scrap price. The machine runs but i was told it's slow. Upon inspection all of the functions feel slow, the machine doesn't really want to pick itself up, and one of the final drives has less power than the other one. I'm going to start reading into the pumps and what not to see what i can learn but do these have two separate hydraulic pumps? I moved it from where i bought it over to where i can work on it and i noticed when i boomed up while tracking the machine started to track faster. Should i check hydraulic pressures or what? Diagnosing hydraulic issues is out of my league. Picture related. It's the machine. Thanks!
Pressures are a good place to start. We'll need a s/n to help you.
It will have 2 pumps in one housing.
Ok. I didn’t get the serial number off the machine as it looks like I need a brush to scratch the tag and I didn’t have one with me. But I did notice the following line looks pinched off. Is this the supply line for the pilot controls? Would this being restricted cause any of the issues I’m experiencing? Picture related.
That looks like the return line from the relief valve for the pilot pump. If it was truly pinched off it could send the pilot pressure sky high causing possible pilot pump failure or blown seals elsewhere in the pilot system. Spin that white filter off and dump it out on a clean rag. If it’s full of filings the pilot pump is toast.
I'll spin it off and report back tomorrow. If that pump is toast would that explain some of these symptoms?
Yes . Without pilot pressure nothing will work right. Would be nice if you could check pilot pressure too. Should be a test fitting right by the accumulator (round globe thing) on the pilot manifold where the damaged hose comes from. I think the 325l was around 500 psi. Later models were about 600. We need a serial number to be sure.
You should start looking for literature before doing anything. The operation and maintenance manual at a minimum and to be on track you will need a service manual. You can buy that stuff on line direct from Cat or some other source. The pumps are Rexroth/Uchida and the system in open center parallel passage with negative control. You could have a pump problem but there is a lot of other stuff you need to check before pulling the pump off the machine. Get the books and familiarize yourself with the component types and locations before spending a lot of money.
Quick update. Started the machine up again today with my friend who is better with these than i am. He cracked the line for the pilot pressure at the pilot pump and there's no pressure. It's barely dribbling. He's going to grab his gauges tomorrow and and come back monday and check pilot pressure just for kicks and then check the main pump pressure. He's wondering if the main pump pressure is too low to supply the pilot pumps with enough pressure to prime/stroke the pumps to make everything work.
Awesome keep us updated and if you ever want to get rid of it for scrap price, I can arrange trucking. lol
Thanks for checking back in, Mr. Kong! We would love to see how this progresses. I am in the peanut gallery, just watching and learning, only laughing when I screw up. Keep us in the loop.