I own a Cat 336DL LR that has a Pierce Manufacturing stick and boom that was installed on the machine when new. There were issues with the boom cracking due to manufacture defects by Pierce Manufacturing. The boom had to be completely replaced so the local Cat dealer replaced the boom with an updated boom from Pierce. After this was installed the machine was used for about 5 minutes when all of a sudden the bucket cylinder would no longer cycle. It was discovered that there was a catastrophic failure in the bucket cylinder due to the hydraulic system being contaminated which caused the problem. It is obvious that when the new boom was installed (which contained new hydraulic lines) the hydraulic system was contaminated causing the failure. I am curious if anybody else has had similar issues.
If you have any oil sample results in your service records it will greatly help your case. We are talking a BIG TICKET repair here. Later Bob
Likely to be something very specialized. Aftermarket booms are installed on probably less than 1% of machines sold, so the failure not likely to be a common one so you may get very little in the way of response. One comment from your OP struck me - "It is obvious that when the new boom was installed (which contained new hydraulic lines) the hydraulic system was contaminated causing the failure". Has the root cause of failure of the bucket cylinder been 100% conclusively established as contamination..? because without concrete evidence to back up that statement that there is only a suspicion until a full failure analysis of the cylinder is carried out, it could have been a total coincidence. BTW I'm not trying to argue the point with you, just playing Devil's Advocate. As Bob says, it has all the hallmarks of being a very expensive repair.
Bob - Yes we do SOS at every PM and actually had just performed an SOS on the hydraulic system before the new boom was installed. The oil sample showed no issues prior to the failure.
Nige - I completely understand what you are saying and I am always willing to look at both sides and I don't mind the feedback. The one thing I failed to mention is that I have talked to another individual that had almost the exact same failure once the new Pierce boom was installed on their unit. Thus, I am trying to find out if there are other people out there that have had the exact same issue.
What happened with the cylinder that cuased it not to work all of a sudden? Foreign materials usually just gouge the hell out of seals and bores but gradually over a longer period of time than 5 minutes?
You need to look carefully at the Boom/Stick/Bucket geometry. There in lies the problem if many have had this failure. SOS will save you big time in the contamination peeing contest. Later Bob
I don't know if many have had this failure. I just know of one other. It doesn't lie within in the stick/boom/bucket geometry....let me rephrase that. The boom failure may stem from that but that isn't what causes the hydraulic failure. The hydraulic failure occurs after the new boom is installed. The fix for the boom failure was addition of gussets inside the new booms.
Can you post a pic of the failed cylinder apart? Later Bob
When the failed cylinder is pulled apart you need to be there to see whatever bits of extraneous iron get pulled out of it. If there is nothing in the cylinder then maybe it's a case of go looking further afield like the main control valves. As per Bob's comment - good pictures can tell a hell of a story, especially close-up ones of fracture faces (but make sure you take some wide-angle shots as well so that we know what we're looking at).
Get good close up of broken surfaces so we can see beach marks of a stress crack before a fracture if any. Later Bob
I have seen failures like this.Further anaylis proved the problem occured due to external forces such as a missing stop ore a miswelded stop ethe wrong bore placement and such this cause internal damage not conntamination as first thought I would look for interferenc deflecting the cyl off the center line of its stroke thanks
Agree you need to determine the cause of the failure. Did part A fail and damage part B or was it the other way around? A year or two back we had a major failure with a Cat Hoe, think it was a 350?, anyhow this hoe was used with a hyd. hammer to break oversize rock in quarry. One of the main boom cylinders failed. When the Cat dealer started checking it out they found the inside of the barrel the piston to be gouged up big time. Like 1/4 inch deep gouges! This is when they started looking at the machine real close and noticed that area behind the main boom cylinders to be packed with mud and stone. When hammer was being used the main boom would be maybe half way down to get hammer away from cab with the stone chips. Problem was this stone would fill the area behind the cylinders over time and when operator would raise boom up it would pack it in harder. After a time this created a artificial stop that put some major side loads on the cylinder enough to finally cause the rod to bend and score the barrels of the boom cylinders. I was there when the dealer an factory people were explaining it to the big bosses in our company. I stayed back a bit as the operator who runs this machine is said to be a hunting buddy of one of the big bosses! As I heard they had to replace both boom cylinders and locate a used main control valve as one or more spools was seized in the bore. Plus complete disassembling and cleaning of the hyd. system. I have a feeling the operator has been instructed to clean the area behind those cylinders quite often!! Would have liked to got some pictures but think it would not go over to good with "those in charge" if you know what I mean?