Can't find the air leak.

Jason in Enid

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Oct 10, 2009
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Got a weird little problem with my dredge air system. Early this year I couldnt get enough air to breath while doing some test runs. I assumed it was a bent reed or something else physical, so I did a complete re-build of my compressor. I fire it up yesterday to make sure it was making good air, and still ALMOST nothing. I pull the hose and there is just a tiny bit of air pressure that bled off. But as soon as the hose was off (quick connect) the pop-off OPV starts popping, so it's making pressure. I can plug the air line from a single regulator directly into the compressor and the OPV cycles normally and I can breath just fine from it. Hook the reservoir back up and no pressure. :icon_scratch: :icon_scratch: :icon_scratch:

I put soapy water on all the connections and the reservoir tank and I only find a tiny bleed-by leak at a connection but it's nothing that would be causing problems. Anybody ran into this before? Is there some place I'm not thinking of checking? I can run it directly off the compressor if I have to, but thats not ideal, and not wanted.
 

Your friendly mud wasp has made your unit it's home for spawn. Them bloody things love compressors/related pieces/parts for some reason. OR you just answered your own question as in the line or reserve tank?? MUST absolutely agree with NOT running without a reserve tank EVER .Sage advice in your post. John
 

Jason check hose connections the female gets plugged and rusted the connector may be brass but the check balls are still steel I had my hot water lines plug at connections
 

Your friendly mud wasp has made your unit it's home for spawn. Them bloody things love compressors/related pieces/parts for some reason. OR you just answered your own question as in the line or reserve tank?? MUST absolutely agree with NOT running without a reserve tank EVER .Sage advice in your post. John

It's always stored inside, but it is still making air, just cant get the entire system to pressurize.
 

Jason check hose connections the female gets plugged and rusted the connector may be brass but the check balls are still steel I had my hot water lines plug at connections

I'll give those another look. Probably wont know for certain until I get it to the river where I can submerge everything. I don't think its a plug, because there is pressure when everything is off, but no pressure when everything is hooked together. A plug should still be causing the OPV to activate but no air at the regulator.
 

change out the quick connects, check for obstructions, I still need to fix mine I screw the yellow hose from the reserve tank directly on each time.
 

change out the quick connects, check for obstructions, I still need to fix mine I screw the yellow hose from the reserve tank directly on each time.

Yeah, that's my next course of action if I can't find any obvious problems with the tank or hose. I never liked how this system was setup. The T coming out of the tank has a male on one side and a female on the other side. I'm sure there is some reason for that, but it's a pain in the butt at times. If I have to change all this out, it's getting all females on the outflow side.
 

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A thought just came to me after writing that last post. What if my unused regulator has the leak? The main reg that I plugged directly into the compressor worked fine, but because the other line has opposite fittings I can't try that, and I can't run the tank without that one being connected.

I can fix that if it's the problem, but I got to get it into some water to check.
 

generally they put the male end coming off the compressor so if there is no hose attached like for long arming to keep the compressor cool.
I do it the other way I put a short pipe off the compressor then the female quick connect then just plug in a loose male nipple for when I'm not using the air.
it's basically just just plumbing, sounds like you're using someone else plumbing job, that makes it tough to troubleshoot,
it doesn't need to be overly complex "KISS", eliminate what it isn't to narrow it down, best to fix things at home rather than 100 miles from nowhere.
 

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generally they put the male end coming off the compressor, if there is no hose attached like for long arming to keep the compressor cool.
I do it the other way I put a short pipe off the compressor then the female quick connect then just a loose male nipple for when I'm not using the air.
it's basically just just plumbing, sounds like you're using someone else plumbing job, that makes it tough to troubleshoot,
it doesn't need to be overly complex "KISS", eliminate what it isn't to narrow it down, best to fix things at home rather than 100 miles from nowhere.

Yeah, I bought this dredge used, so I have no idea if its a factory setup or someones own brain-child. Mine has a female coming off the compressor. Short pigtail to the reserve, with the previously mentioned T coming off that.
 

might put just a single female coming off the tank then add a nipple to the Tee just to have it for when you wanted to use the second line.
could be a bunch of small leaks at each connection, kiddie pool or a 5gal. bucket of water, might be time for some new Teflon tape.
probably the regulator they do go bad...
 

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Did you say that the outlet from the tank has a tee with one male connector and one female connector? Under any other circumstances I would always blame the female,,,,,,, but this might be the rare exception,,, the male connector has no shut off/check valve in it,,, the air is just pissing out of it.
 

Did you say that the outlet from the tank has a tee with one male connector and one female connector? Under any other circumstances I would always blame the female,,,,,,, but this might be the rare exception,,, the male connector has no shut off/check valve in it,,, the air is just pissing out of it.

no, I have a reg attached to both the male fitting and the female fitting
 

This is exactly why I used to couple my air lines together when done and put up my dredge. plus I installed small rubber caps over the QD male fittings to keep them "critters" out ! plus I liked sanitizing the mask /lines and anything that had warm /moist air in it to prevent mold accumulation from forming . anything short of that is asking for health problems.
 

A pic of your set up would help.

You said, "I did a complete re-build of my compressor. I fire it up yesterday to make sure it was making good air, and still ALMOST nothing.
But when hooked up, you can still get the pop-off to work.
What's the pop-off psi? Sounds like it still may be the pump because you already said that it makes almost nothing. Sounds like a T80, I stopped using them because of this. Could also be that because it's getting old, that you need a different ratio on the pulleys to get enough output.
Pics would help but Brands would also. Keene/ Proline/ Thomas/ Gast - need more info. Could also be a simple crack in the Tee or one of the fittings. Set it up so that you can run either one at any time. Females go on the Tee and the pop-off goes either on the compressor or in the line before the tee. If it won't fill the air tank then it really sounds like a problem with the pump but... It could be the seal on the clean out door on the air tank... Once again brand of air tank and pics would really help :)
 

Here it is a week late and still no answer as to whatzup?? Just saying folks have tried to help and silence?? Strange problem as described and what caused the problem "REALLY" is of interest and assist to many-John
 

Here it is a week late and still no answer as to whatzup?? Just saying folks have tried to help and silence?? Strange problem as described and what caused the problem "REALLY" is of interest and assist to many-John

He has been out dredging John I know he had to replace the pulley on the T80 it exploded.
 

Here it is a week late and still no answer as to whatzup?? Just saying folks have tried to help and silence?? Strange problem as described and what caused the problem "REALLY" is of interest and assist to many-John

He has been out dredging John I know he had to replace the pulley on the T80 it exploded.

Yeah, I took it out to Colorado and it was working the first day, then it started sounding funny, then the flywheel exploded on me. Replaced it with the closest size ( I thought would work) but I couldn't get the belt tight enough to stay engaged. It would pump air for a while and get my hopes up then lose grip, so I just long-armed it with a snorkel the rest of the time. Dropping everything to go back into town to find a smaller belt, then dismantling the pump to install it didnt seem worth the time lost. I think it's got an internal , like with the bearings because this is the second time it's blown apart a flywheel. I haven't torn it down yet to check, but it may need a some more parts (at least a proper sized flywheel).

But I moved as much gravel and sand as I could last week, just couldn't get down into the deep layer I wanted. River was freekin BRUTAL. running 850-900 from all the rains the week I was there. I just have to get my super cons panned out. I know I saw a picker (Arkansas river nuggett LOL) in my son's cons!

Thank you to everyone to offered advise. I'm pretty sure it is probably a worn out pump combined with worn out quick connects. Got some more work to do around the house and then I will tear into the pump.

I will say that I was VERY happy with the performance of the 3" dredge I built for my son. Tons of suction on the nozzle, always kept the oversized cobble moving along, very little blonds held but plenty of black sands. Never packed up with material either. Performed exactly as I had hoped for!
 

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