help with my bucket truck somebody please

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mg1944

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I have an MTI lift. It started blowing supply lines up in the platform control valve area. Blew one yesterday and another today. They just popped out of the compression collars. Easy to fix, I just snipped the lines shorter and reconnected them. The bucket controls have been really jerky and generally too fast to respond when compared to the ground controls, combined with the lines just blowing off the fittings like that, leads me to believe that the pressure setting is too high for the bucket controls.
My manual says that pilot controls that seem too responsive is an indication of too much pressure in the pilot system.
The manual also specifies no more than 300 lbs pressure in that pilot circuit.
I don't have a gauge. I consulted a Teco tech site and identified the type of pressure regulating valve on my unit, Teco said to lower the pressure, back the allen head screw out counter clockwise. I backed it out 3/4 of a turn and the controls seem smoother with less jerkiness. Mt bucket also has a pressure reducing valve for fast and slow operation. I have that dialed down to next to nothing so the bucket just floats around slower than a snail. I then went through all the other collar type plastic fittings in the bucket control box and tightened them all, some of which were surprisingly under torqued.
All has been going well for several days, I thought I had it licked until today when a line on the supply side of the emergency over ride shut off blew down on the deck. Same thing, the plastic line just blew right out of the collar.
What is going on?
Do I have too much pressure in the system?
Are the plastic, nylon I guess, lines shot and need to be replaced?
They look fine, like brand new actually.
Do I need to snip off all the ends and replace all the collars, sort of starting fresh compression connections?
I am going over to talk to Altec about it Friday, maybe between their advice if any, and any input I can get from you folks I can figure out where to proceed with this problem.
Thanks in advance for any knowledge you can offer.
 
Have you resolved the issue? It sounds like a pressure regulation issue, which is often valve related.
No, I reconnected the line that blew off by making a fresh end cut in the nylon tubing and expanding the lock collar with a tapered punch to get it over the "new" end of the line. I'm suspecting the pressure reducing valve, which I am going to verify with a pressure gauge on the test port. I am trying to get new lock collars from Altec, but that simple little part is not so simple apparently for them to obtain.
I really do think that they make everything as difficult as possible so that you just give up and make a site service call to them for $1,000 an hour most likely and their mechanic just happens to have a box of those collars you need on his truck. Anyway, the book specifies 300 lbs for pilot pressure, and the old guy up at Neuco I talked with told me 325 to 350 ish. He also said that he has seen in his 20 years working on this stuff maybe two pressure valves that went bad.
I'm hoping that when I get the gauge on there under pressure and I crank the allen screw on the valve, nothing happens on the gauge, then I'll know it has been all about a bad regulator valve.
so, when the gauge gets here it will tell the tale.
Until then, I'm grounded on terra firma.
Thanks for asking.
 

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