It’s been a while since I did an update, cleaning the machine is tedious and not very inspiring!
Let’s start with the sump, or hydraulic tank that’s located inside the bottom of the machine. Getting the tank out of the machine full of hydraulic fluid is “fun”. It must weigh over 50Kg when full! You have to remove the two hydraulic hoses and disconnect the wiring to the motor before it will squeeze through the door. To get at the hydraulic hoses you need to remove the front switch panel. I’d recommend draining as much of the fluid as possible before attempting this. The pump itself can be used to pump it out…..but it’s at a pressure so not feeling that brave I used a manual pump.
A few pictures of the gubbins after I’d initially cleaned them…..well wiped off the majority of the thick goo so you can actually hopefully recognise a few of the parts. It’s a simple system, a 4 pole motor drives through a chain and sprocket a pump to provide hydraulic pressure for the system. The manual says the oil should be changed annually, but I think this has been in the tank for the full 50 years of its life! I know that I used just paper towel to block the ports but the photos were before the brilliant advise already provided. In later photos I’ve headed the recommendatio.
So first order of the day was to disassemble and start cleaning!
The tank looks a bit better after a spring clean.
The oil sits in the tank and the actual pump system sits on a platform connected through anti vibration pads that connect to the three tabs around the tank.
The platform is a casting, machined and ribbed for additional strength. It’s a substantial piece, not just a thin metal fabrication we would find today. The slots on the left are T slots that are used to connect and slide the motor to tension the chain.
The sprockets and chain were worn out. The tips of the teeth on the sprockets were sharp enough to cut any unwary fingers venturing close. I’ve popped the dimensions of the two sprockets on the old units and shown them against the new ones Ive replaced them with. The new sprockets have tapered locking bushes to fit the spindles. I used Reynolds simplex roller chain 3/8” pitch and appropriate sprockets.
I took the motor apart and replaced the bearings. Might as well as they are cheap and it helped cleaning up the motor. These were replaced with SKF sealed for life bearings.
The sprockets are shown as I originally put them on, however, they foul the shroud this way around, and I subsequently reversed them. Made fitting them a little tricky to tighten up the grub screws, but there is enough room for a standard Allen key.
I didn’t take apart the pump, it has a few gaskets and seals inside it which I can’t find spares for. Ideally I would want to do this as I’m sure it’s full of crud. If anyone has taken this apart and knows where to get seals from please give me a shout out. I could use gasket compound ratter than gaskets. At the moment the plan is to flush it through with fresh hydraulic fluid.
I checked the dynamic balance of the new sprockets, and found that they were very good. Only a little adjustment being required to achieve almost imperceptible vibration.