I'm an operator of a Mi-TM JCW3504-2MBH; 3500PSI/3.7GPM belt drive for my gov't field station. Honda GX390 and AR pump (not sure of the pump model).
We've learned from past mistakes with pressure washers and have really been meticulous with maintenance and operations especially as it relates to avoiding cavitation, not enough flow, running in by-pass mode, etc.
Out of the blue last week, our pump started leaking opposite the inlet plumbing, out the end of what I now know is called a relief valve. I could tell that it wasn't leaking from around the threads of the valve and was coming out of the end, but since the end sits only about 1/4" from the belt housing frame, I couldn't tell what the end was supposed to be or if something was damaged. The PW'er worked fine the day I discovered the leak except that it took a little longer to purge than normal, but the next day it started losing pressure while a Youth Conservation Corps (YCC) kid was using it. Luckily the kid remembered what I told him about operations of the machine and shut it off immediately when it lost pressure and called someone over to help.
When I got back from my fish distribution trip, I found the part in the manual; called technical support; and the technician said that it usually goes bad if operators are running in by-pass mode too much (we don't; we limit running without spraying to less than one minute intervals max); or it can go bad if some crap gets in to it and can cause it to rupture (possible, but we run it with two filters and the filters, gravity tank and lines were squeaky clean). The technician also stated that they often have to cut the elbow off on the relief valves for these models, because they are so close to the belt housings. Just for reference, our water supply is 45 degrees and it may sit in a tank two or three hours max, so our supply water is not hot in the beginning.
I removed the leaking valve and it was basically flush rubber or plastic end (no elbow) that had a cut mark on it; either from the factory or somehow we accidentally cut it. It had a small hole out the end, but I suspect it's supposed to. I have no way of knowing what the valve end looked like before it started leaking or what caused it to leak, because it can't be seen unless one removes it from our unit. I always assumed that relief-valve bolt was just a bolt, but now I know it's more than just a bolt. We had the new valve over-nighted, and I was able to mount it without cutting the elbow, which was my hope, but it's only about a sixteenth of an inch from the belt housing casing but now the end can be seen because I've pointed the elbow outward towards the crank side of the machine.
The boss really stressed out when the unit went down. He wanted me to Jerry Rigg it some way to keep it going, but I talked him into just waiting till the next afternoon (we've gone down this road before operating machines when we shouldn't have). He gave in and I had it going the next day at the close of business. We really need a second unit, but the bosses boss said we don't have money for it now. We're gov't so we have to wait for piles of money for certain projects and there is no money for the pressure washer project right now. But we are getting a $60K distribution truck to replace a 2007 Int'l we've had to keep buying over an over through repair bills.
My questions are:
Is a relief valve a common part to fail just by happenstance or normal wear?
If this is not a common part to fail, is the technician right about the most likely causes of failure, or is it something else we may be doing or not doing?
I wonder if cutting the elbow off at the factory (if in fact it was cut off like the technician suggested), if that practice could weaken this part and cause it to fail after only a few months of use?
Is there a risk of leaving this relief valve on the unit unmodified if it is extremely close to the belt housing? I'm almost scared to cut the thing like I suspect the factory did, because then I may have a second leaking valve. We overnighted two of them, and it was $60.
https://www.google.com/search?q=mi-...ChMI77eonq2NxgIVQ5eACh3qrABh&biw=1280&bih=648
We've learned from past mistakes with pressure washers and have really been meticulous with maintenance and operations especially as it relates to avoiding cavitation, not enough flow, running in by-pass mode, etc.
Out of the blue last week, our pump started leaking opposite the inlet plumbing, out the end of what I now know is called a relief valve. I could tell that it wasn't leaking from around the threads of the valve and was coming out of the end, but since the end sits only about 1/4" from the belt housing frame, I couldn't tell what the end was supposed to be or if something was damaged. The PW'er worked fine the day I discovered the leak except that it took a little longer to purge than normal, but the next day it started losing pressure while a Youth Conservation Corps (YCC) kid was using it. Luckily the kid remembered what I told him about operations of the machine and shut it off immediately when it lost pressure and called someone over to help.
When I got back from my fish distribution trip, I found the part in the manual; called technical support; and the technician said that it usually goes bad if operators are running in by-pass mode too much (we don't; we limit running without spraying to less than one minute intervals max); or it can go bad if some crap gets in to it and can cause it to rupture (possible, but we run it with two filters and the filters, gravity tank and lines were squeaky clean). The technician also stated that they often have to cut the elbow off on the relief valves for these models, because they are so close to the belt housings. Just for reference, our water supply is 45 degrees and it may sit in a tank two or three hours max, so our supply water is not hot in the beginning.
I removed the leaking valve and it was basically flush rubber or plastic end (no elbow) that had a cut mark on it; either from the factory or somehow we accidentally cut it. It had a small hole out the end, but I suspect it's supposed to. I have no way of knowing what the valve end looked like before it started leaking or what caused it to leak, because it can't be seen unless one removes it from our unit. I always assumed that relief-valve bolt was just a bolt, but now I know it's more than just a bolt. We had the new valve over-nighted, and I was able to mount it without cutting the elbow, which was my hope, but it's only about a sixteenth of an inch from the belt housing casing but now the end can be seen because I've pointed the elbow outward towards the crank side of the machine.
The boss really stressed out when the unit went down. He wanted me to Jerry Rigg it some way to keep it going, but I talked him into just waiting till the next afternoon (we've gone down this road before operating machines when we shouldn't have). He gave in and I had it going the next day at the close of business. We really need a second unit, but the bosses boss said we don't have money for it now. We're gov't so we have to wait for piles of money for certain projects and there is no money for the pressure washer project right now. But we are getting a $60K distribution truck to replace a 2007 Int'l we've had to keep buying over an over through repair bills.
My questions are:
Is a relief valve a common part to fail just by happenstance or normal wear?
If this is not a common part to fail, is the technician right about the most likely causes of failure, or is it something else we may be doing or not doing?
I wonder if cutting the elbow off at the factory (if in fact it was cut off like the technician suggested), if that practice could weaken this part and cause it to fail after only a few months of use?
Is there a risk of leaving this relief valve on the unit unmodified if it is extremely close to the belt housing? I'm almost scared to cut the thing like I suspect the factory did, because then I may have a second leaking valve. We overnighted two of them, and it was $60.
https://www.google.com/search?q=mi-...ChMI77eonq2NxgIVQ5eACh3qrABh&biw=1280&bih=648
