Hi, I am looking for a source to purchase some hydraulic boom cylynders for a P&H 312 Excavator. Help would be greatly apreciated.I am in Alberta. Thanks in advance.
What's wrong with the existing cylinders? Maybe a place like General Gear or Equipment Trader under dismantled machines might have some but if the barrels are good you could have new rods made. They might be repairable too. Just depends what the problem is.
I measured Piston shaft, bore and stroke. I guess these cyinders could be rebuilt. Not sure I want to do it, but I'm sure I could if I need to. The shafts (no noticable pitting or wear spots) and seals are not as bad as I thought. Just a very small weep on a couple of them. It looked worse when I first checked it out. This machine hasn't been cleaned up for a long time and the weep was just a build up over time. I plan to power wash it and might have to replace some grease nipples when I can see them. The hydraulic resevoir was low, so I topped it up. I don't where General Gear or Equipment Trader are based out of. They could be a resource. I would like to check them out at some point. You have seen my other posts, so you probably get that this is a machine I just purchased. I plan to work it on my farm, but I want to take care of any obvious problems before they become larger. Not my first machine, but help is good.
You don't have to replace cylinders that leak. Taking them apart and replacing seals is one of the most common maintenance practices on all heavy equipment. Typically cylinder seals last for many thousands of hours so you don't have to do seals very often. Replacing cylinders would cost thousands of $$$$$. One other thing, your machine is likely to have leaks. Not necessarily from the cylinders but there is maze of hoses and fittings that several tiny leaks can add up. I have a parts manual for an H418 somewhere in storage and the hyd. schematic would make your head spin. I remember the guy who owned 6 P&H's said they were leakers and you had to keep track of the hyd. oil level.
So, I checked out the leal. It's the main piston on the top of the boom. Definately a seal
Do U know if the seal can be changed without pulling the cylinder completely apart? Definately the main piston on the top of the boom.
You might be able to pull the rod out and leave the barrel on the machine but the cylinder has to come completely apart. Change all the seals when you have it apart. Is that tag on the cylinder? I doubt it will help you. You'll need take the rid to a hyd. or seal shop to match the seals.
U know, that is a good idea. I guess once it's apart I could replace the seals. If they were generic, that would be good.
Not necessarily generic but should be able to match them.
I would pull cylinder off the machine. Before you start get yourself some hydraulic plugs and caps ,twice as many as you think you need and a range of sizes they are cheap compared to oil spills or contamination in your system. im sure they would be JIC,even if you Id them by wrench size the hyd shop with set you up with the right stuff. This will keep 99% of your oil in the machine or in the cylinder instead of on the ground .Tape and rags just makes a mess. If you are into some shop work like making your own slug wrenches and something solid to hold the cylinder down ,go for it and reseal it ,if not take the whole cylinder into the hyd shop.They are usually well equiped and quick on that stuff unless things are seized or damaged .The nuts on the rod end holding the piston on can be extremely tight sometimes.
I think if you've never worked on a cylinder before it's better to just take it to a shop with a cylinder bench. It will save you a lot of frustration and possible damage. That's a big cylinder and not easily replaceable.