rebuild hydraulic breaker

Working for a rental company and we've got a Kent KF9 hydraulic breaker (SN: F9-7261) leaking a decent amount of hydraulic fluid. In the past management outsourced the rebuilds due to the nitrogen charge it requires. But I've been trying to find a service manual, or even some form of training out there with no luck. Main question is How dangerous are these breakers to someone with no experience with them, and what shop equipment would be necessary in order to begin rebuilding other makes and model breakers?

Definitely want a manual for tear down. Sometimes you need to put in longer bolts to hold things together as you release tension, some gas powered compactors/jumping jacks are the same way fyi. We have one guy at the shop that rebuilds hammers of all sizes. This way it’s done right as some mistakes can destroy the hammer very quickly. If you don’t have a nitrogen charge kit I’d suggest starting there and send out the hammers for rebuilding until you find a mentor.

I kind of agree with Zewnten. There is a fair amount of special tooling requirements for hydraulic breaker maintenance. Not the least of which is what is just required to service only the nitrogen parts. I personally have about seven different nitro charging kits on my service truck for the most popular brands of hammers in my area (npk, modern tramac, bti, allied, etc) and another three or four for less popular brands in the shop. A couple of other popular brands I just don't have because they come up less often like older tarmac and cat. The charge kits for these particular hammers are either so awkward to use or just so expensive that I take the accumulators to one of the local dealerships to be charged. That is just the nitrogen side of things. The next big issue is the torque requirements for just about any breaker larger that the one you are talking about. Just the side plate bolts on these breakers have a torque spec so high that they require more specialized equipment. The cheapest option would be a mechanical torque multiplier. And that is a fairly dangerous piece of equipment even for an experienced hand. Tie rod torque is worse. If you start right there, with just those two expenditures, I would have a hard time believing that you could even half equip your shop for hammer service for less than ten grand. That is just the easy part... That is just money spent. The next part comes down to diagnosis and tech knowledge. You need to know when a breaker problem is because of the actual breaker or the carrier running it. Oh, yeah... That requires at least another special tool. You need to have a pretty good flow meter and the knowledge to know what it tells you. (That is an additional four grand) And the experience to know which breakers work best with which machine. This is just my personal opinion, Komatsu's have so much back pressure that you can only mount npk breakers on them. I hope someone takes exception to that statement. I know there are a couple of komatsu gurus here. And I have never really understood why this seems to be the case. Even then. Lets just say at this point you are about fifteen grand into setting up this new enterprise. Then you have to quite often fabricate tooling for just taking breakers apart. I have serviced so many tramac breakers that I would swear that what I need has to exist on the service truck. But I constantly have to fabricate new tools. I haven't even mentioned bushings.

Thank you for your input, with all that being said, we're probably gonna continue out-sourcing the breakers then.

Once you discharge the nitrogen, they aren't dangerous. Each brand has its little qwerks. The easiest hammers to work on are NPKs.

Honestly hammers are probably the easiest the easiest thing out there to rebuild. As long as you've got a crane/hoist, torque spec for the tie rods, a nitrogen charge kit and nitrogen specs you're pretty much good to go. Like mentioned above, once the nitrogen pressure is discharged there's nothing really dangerous about them besides the obvious stuff.

MrElectric03 said: Once you discharge the nitrogen, they aren't dangerous. Each brand has its little qwerks. The easiest hammers to work on are NPKs. Click to expand... NPK were my least favourite. I could get just about any other breaker brand rebuilt and out the door an hour or so faster. I will say their service manuals were by far the best of any breaker manufacturer though. Very thorough and tons of great detail.

Well I work for NPK so I admit I am a bit biased. But the way the hammer is removed from the bracket, no pit needed. Really no special tools, tie rods can be reused many times over, internals are all replaceable unlike most hammers no boring needed, no bladders or accumulator, simple valve. The biggest pain is cutting the bushings out and that will be a thing of the past before long.

A pit? Just stand it up and crane out the power cell.

92U 3406 said: A pit? Just stand it up and crane out the power cell. Click to expand... I seem to recall dragging a few hammers about the shop floor and nudging them back in wit a forklift

92U 3406 said: A pit? Just stand it up and crane out the power cell. Click to expand... I suppose it depends on the size of hammer and height of the roof/crane. Shops that specialized in hammer work would have a pit to make it easier.

Interesting. I've never heard of using a pit and I spent a couple years at a breaker rebuild shop. Have you got any pictures or can you explain how the pit works? I'm genuinely curious about this.