Hi,

I recently acquired a used MTH Premier Alco S-2 PS3 model # 20-20585-1. It's a light smoker, and when I opened up the smoke unit it looks like I definitely need a new wick but also probably a new smoke unit. The gasket between the fan and fluid reservoir is in rough shape and the heating element looks pretty rough.

 

The unit is a weird one that is much smaller than the others I've encountered.  The fan is positioned to the side rather that the typical fire/aft arrangement.   Does anyone know the specific part numbers for these offhand? There are no parts diagrams on MTH's website for this particular diesel that I can find, and the smoke units I've found on their parts site don't all have pictures. 

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I added some pictures.  The last one is a good shot of the heating element.  It looks pretty cooked to me, but I'm not sure.  I think one of the issues could be that the resistor is shorting out on the metal case.  The clearances are extremely tight.

Oh, and after some further investigation, I found that the thing is leaking everywhere.  There was smoke fluid in every nook and cranny possible, and I think it ruined the speaker, which explains the low sound output.

that's just a standard smoke unit and can easily be repaired you just need a new wick and replace the top gasket. as far as the short you said  is concerned if there was a short from the element to smoke unit case you would have blown your engine board! the resister or heater element is normally centered inside the smoke unit  tank so as not to short to metal unit! would only cost if you do the job Is  the cost of the gasket and wick!unless you send to someone to get rebuilt. there not hard to replace!

Alan

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ASC Tech MTH school completed! 2019 !

As long as your fan motor is working and your heating element is getting hot and not causing any additional problems, you should only have to replace the cardboard gasket and the wick.  Your heating element looks like all of the others I have seen.  The gaskets can be ordered directly from MTH.  They are typically $2 each.  I like to use "tiki torch" wicks in all of my smoke units.  Just cut them down to size.

These smaller smoke units do not smoke as well as their larger counterparts so don't expect a lot.  Most likely due to less air flow and only one heating element.  Also, these smaller units are extremely easy to overfill, so be careful.

-Ryan

rplst8 posted:

I recently acquired a used MTH Premier Alco S-2 PS3 model # 20-20585-1. It's a light smoker, and when I opened up the smoke unit it looks like I definitely need a new wick but also probably a new smoke unit. The gasket between the fan and fluid reservoir is in rough shape and the heating element looks pretty rough.

Don't expect too much from that smoke unit, it's nothing like the full sized smoke units as far as output. 

Use GREAT caution when you reassemble this unit!  If that resistor shorts on either end to the case, you will be shopping for a new PS/3 board!  The clearances are pretty tight in there.  Some of these units have a lining to prevent the resistor from contacting the diecast sides, but the last couple I took apart didn't have that lining.

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Alan Mancus posted:

that's just a standard smoke unit and can easily be repaired you just need a new wick and replace the top gasket. as far as the short you said  is concerned if there was a short from the element to smoke unit case you would have blown your engine board! the resister or heater element is normally centered inside the smoke unit  tank so as not to short to metal unit! would only cost if you do the job Is  the cost of the gasket and wick!unless you send to someone to get rebuilt. there not hard to replace!

Alan

The top gasket may be bad as well, but I was specifically talking about the one between the fan unit and the reservoir.  There is a really tiny rubber one that is pretty brittle.  I think that's where it may have been leaking from.

Also, "short" was probably the wrong word to use.  It's not that the both sides were touching the metal reservoir to cause a complete short, but rather that one side or other was coming in contact with the wall of the reservoir, causing it to act like a heat sink.  The larger metal surface area would then cause it burn cooler, resulting in less smoke output.  I'm thinking because of that, the previous owner probably got overzealous with the smoke fluid.

I've watched some videos of other MTH Alco S-2s and mine was nowhere near the smoke output of what I saw.

You do not want ANY part of the smoke resistor to contact the side of the reservoir!!!!  That will damage the PS/3 board in a heartbeat!  NOTHING can be grounded for PS/2 or PS/3 except the input power connection.  Lights, smoke, motors, are all totally isolated from frame ground.  If they're not, you will be buying a new board, or at least paying for a component repair if you're lucky and it only takes out the driver for the smoke unit.

FWIW, that tiny rubber gasket isn't available either, so you'll have to make one of those.

gunrunnerjohn posted:

Use GREAT caution when you reassemble this unit!  If that resistor shorts on either end to the case, you will be shopping for a new PS/3 board!  The clearances are pretty tight in there.  Some of these units have a lining to prevent the resistor from contacting the diecast sides, but the last couple I took apart didn't have that lining.

I'll have to double check for a lining.  I've seen them in other units like you say, but I didn't notice one here.  This is a 2016 PS3 Premier unit, so you'd think they wouldn't cut corners like that.

I think if the common side of the resistor touched the wall it wouldn't destroy the board, would it?  Only the hot/live side, right?

gunrunnerjohn posted:

NOTHING can be grounded for PS/2 or PS/3 except the input power connection.  Lights, smoke, motors, are all totally isolated from frame ground.  If they're not, you will be buying a new board, or at least paying for a component repair if you're lucky and it only takes out the driver for the smoke unit.

Ah, I see.  Well I will take care.  I'm guessing the low smoke output was caused by a bad wick and then overfilling, then.

There is no "common" side when it comes to frame ground with PS/2 or PS/3, one side is PV, the other side is the smoke drive.  Either one shorted to the frame will cook things, which one decides what cooks.

Well, it should have "visible" smoke.  I used one of those small smoke units in a Weaver brass Pacific G2sa to replace the Seuthe unit as the full sized smoke wouldn't fit.  It works pretty well, I probably get smoke like your videos, but nothing like the full sized smoke units.

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