Hello New to the forum as have recently bought my first excavator, a 2016 5T Hitachi. Boom bottom pin wont take grease . It was sitting for a while before i purchased it and the grease looked quite dry around the joins here. Have already looked at many suggestions in this great forum and tried the following but with NO LUCK so far 1) Pulled Grease Zerk and checked is clear 2) Banged the Pins with a hammer 3) Pressurised the grease gun while moving the boom 4) Heated with a plumbers torch at the ends and centre 5) Dig Out Old Grease With Wire - this cavity is tight and cannot get a wire very far in nor to the sides. Not sure if that is the nature of this particular cavity or whether there is something blocking as people suggest sometimes happens in other posts. I was only able to get the new grease and a tiny bit of old dark grease out. 6) Spray Brake Fluid into the hole. Due to the vertical and small accessible size of this cavity, it would not accept very much. 7) Drizzle Motor Oil around joins where old grease is several times so as to penetrate and remove any blocks So yeah after all this i still have a blockage. I suspect there could be something in point 5 that is the issue, or else I need to try one of the methods more thoroughly. But any suggestions are very WELCOME And thankyou PLENTY for reading
Removing the pin is about the only option left to you, you've certainly tried all the others. The design of the lube pathway is probably a couple of spiral grooves in the bushing. Once these spiral grooves block with hardened grease/dirt mixture, you won't have much success until you remove the pin and physically clean out the spiral grooves. Longitudinally-drilled pins can often be cleaned out using a long drill, but that grease setup on your machine doesn't lend itself to any cleaning out with a drill - because even if you drilled the lube hole out down to the pin, you still need those spiral grooves in the bushing cleaned out, to ensure the proper spread of grease.
Plumb up a porta power pump to the fitting and put some pressure on it. If it does not open up put some heat on it. Stop before you hurt the hose.
I misrread that, oops.
Thanks OzDozer. I might retry the things i have done already and then pressurise again. Taking the pin out is a bit out of my league just yet but will get my mechanic if need be. Appreciate the help
Grease hammer is another option. Plus a good penetrate oil in the grease hole and let it be a few days. Keep juicing it. Helps to soften the grease. I've had to pull the pin and use a drill on bad ones before though, was harrrdd! Or just smear some grease on the zerk and claim you greased it. Had a guy at work grease like 10 pieces of iron and never come in for more grease. Usually takes half a tube to a tube or so each. Went outside figuring he was goofing off and found what he was doing. Boss was less than happy!
Hi. Do you mean a hydraulic hand pump with a thread to match the hole from where the grease zerk came, or with an an attachment for a grease zerk? Thankyou
Thread it in.
A porta-power pump produces a maximum of 10,000psi - and you can develop up to 10,000psi even with a good hand-operated grease gun. So, personally, I can't see the real gain with a porta-power. I'd have to opine the grease nipple threads are likely to strip if you go much over 10,000psi pressure. Bite the bullet and knock the pin out. That way, you can lube it with Never-Seez when it goes back in - so it comes out much easier next time!
Seen this way too many times.
This. It's only a mini-ex FFS, we're not talking about a pin that weighs 100 pounds or anything like it. Reading your OP you've tried pretty much everything and if none of that worked then knocking the pin out is the best option left, and the best part of it is that only one bolt holds the pin in place. BTW it's boom cylinder pin which makes removing it much less of a job than it would be if it was the main boom pin.
A porta power might work, but the grease fitting threads are metric so it will be more work to hook up. A grease gun can pump light oil like ATF, or naptha, you could even take the coupler and zirk off and thread the hose directly, but again the metric threads. That cylinder can probably be set up with the bucket safely curled and set in a slight hole or against a tree so there's no chance of it moving, and swing the cylinder out of the way if you need to get a little access to the bore. Probably you'll just have to work to get it where there's no boom weight on the pin, then pull that retaining bolt and push the pin JUST PAST HALF WAY through the cylinder, that should expose the inside of the grease passage and it should pop right out when you pump grease into the zirk. Might not even have to take the pin out, and fight to line it back up. If not, come back and ask again.
I was thinking more along these lines, if you have one avail: P2282 P2282, Two Speed, Ultra-High Pressure Hydraulic Hand Pump, 60 in3 Usable Oil, 40,000 psi www.enerpac.com
I'm getting it. I will try the pin just past halfway method first, then if still no good, the whole pin. Was just concerned about getting it back in but should be ok. Also, once its past halfway, others have said to see if there is still restriction from the metal which may have moved and if so, drill through it first before putting pin back. cheers
If you put the stick in a vertical position and rest the bucket flat on the ground as per the illustration below that should take all the weight off the boom cylinder and permit the pin to be driven out relatively easily. If you can find a piece of metal pipe a similar diameter to the pin you could drive the pin all the way out and use the pipe to maintain alignment. Beware that over a period of time the cylinder might just creep a touch which will knock the alignment off.
Some times the bush can spin and block off the grease hole which is a pain. You can try a grease impact driver. Here is a link to some one using one on YouTube but there are better quality ones to buy than the one shown in video. They work very well but i don't like the look of this one as the better ones seal better on the zerk.
There is better one. ATD-5070 ATD 5070 Grease Fitting Unblocker Zerk Hammer - tooldesk.com LNI-5805 Lincoln Impact Grease Fitting Cleaner - tooldesk.com
Until you remove the pin and clean out all the dried dirt/grease mix it will never lube right. It's not "if I can get it to take grease".........it's more about "is the grease I'm getting in it sufficient to lube the pin and bushing correctly."
I had limited success with those.
I ran into people at a paper mill doing the porta-power deal. If you clean out the hole under the fitting and fill it with good penetrating oil and or put it in the hose that helps. Some of those guys even used gasoline ( sounds like a bad idea to me ). Then put pressure on it and many open up. If not sometimes I apply some heat. Nothing even close to yellow just maybe 200 degrees F. If that does not work there is probably a bushing turned or the hole is packed with metal. On nice machines now some paint is burned off and I do not like that. Down side to the paper mill is then it is serviced and sent back out for its regular service interval. Likely to have problems and more like Vetech63 said. Equipment I am around I can grease very regular until I am sure it is worked out. Question the hand grease gun pressure. My air grease pumps have a 5,800 PSI hose on them. When the hand guns will not grease a fitting ( which they may that the air operated units did not ) I have at times cranked the air regulator up to 150 PSI and they pushed grease through a fitting that none of my hand guns would. Also am not saying anyone is wrong. I never made an adapter hose for metric fittings. Did not see spending the time and money. Took the pins out.
Many grease gun sellers advertise 10,000psi capability. Of course, that's an absolute maximum, and it requires serious effort on handles, or maximum air pressure on air-operated ones. https://www.raptorsupplies.com.au/pd/lincoln/1142
porta power .. thin fluid ... heat ... and movement
What make is machine. Hitachi useta use 1/8 bsp.
Remove the zerk, dig all the crap out with a small drill bit and brake cleaner. Plumb in a adapter fitting and connect a portapower with a thin solvent. Keep it pressured up for days if necessary. This has worked for me several times. Otherwise as stated earlier remove the pin...
On larger machines, back in my oiler days, I had good luck shooting some 80w90 in the zerk with the squeaky pin. Often, the pin would starting taking grease again.
A good lever grease gun is good for 10,000 PSI, the same as most porta-power pumps. No need to make a potential dangerous situation. Knock the pin out half way, clean that side and knock it back the other way half out and clean that side.