What I Learned About the MTM Hydro Yesterday

[swanicyouth]

So, a lot of us are using the MTM Hydro Foamer.

After about a year or so, I took mine apart to clean it. It was pretty clean, then I put it back together. When I put it back together, I applied Teflon tape to all the threads and torqued everything down tightly. I did this because the connection above the bottle head (not the plastic bottle) always seems to come "loose".

I'm talking about the threads at the end of the pick here:

You can see the Teflon tape peeking out at the end of the pick - those threads.

Then I put it all back together, everything very tight. So, yesterday I went to use it. Right away - no soap. It would not eject any soap at all. I figured I messed it up somehow when I took it apart. But I thought about it and realized I put it all back together exactly as it came apart.

The only real difference I could think of is the threads identified were now very tight. So I loosened them. I had soap. I found that this must be how the foamer intakes air.

But, what was was interesting was, I found the MORE I loosened them, the thicker and clinger the foam became. I was always actually tightening these up with my hand. I could actually move the threads while spraying foam and it was making a big difference in the "clinginess" and thickness of the foam.

I guess this is another hidden adjustment, at least I didn't know about it. Anyway, with those threads fairly loose, or "adjusted" while spraying, I was able to get foam that was thicker and clung to the surface better than I have ever before.

I was aware of the other two adjustments (black plastic knob on top controls amount of soap and black plastic cone on front controls spray pattern). But, this adjustment seems to control the AMOUNT OF AIR allowed in the foam mixture.

Maybe I'm the only one that didn't know this, but I suspect this may be the cause of the occasional poor performance reported by the MTM or someone whose MTM seems to be "not what it used to be".

BTW I'm using about 3oz of Maxi Suds II exclusively pretty much as my soap and it just seems to work very well. I've have a bottle of the DP, but like MSII much better.

 

[Bunky]

I would find it hard to believe they are relying that for air intake. I would guess there is an air inlet port that is plugged.

 

[swanicyouth]

I would find it hard to believe they are relying that for air intake. I would guess there is an air inlet port that is plugged.

Try it. Try turning those threads while your spraying.

Nothing is plugged. I took it apart and it was very clean, and put it back together even cleaner. Its always worked well, and works even better now I left some "slack" in those threads.

Maybe this hole has something to do with it?

 

[Bunky]

I have a Camspray foam cannon so I cannot compare first hand but my guess such a hole could serve that purpose. I would expect additional air to affect the results though.

 

[ken tuep]

I thought the hole under the dial was the intake.

Sent from my SAMSUNG-SGH-I777 using AG Online

 

[Setec Astronomy]

Maybe this hole has something to do with it?

I think that hole is just to let air into the bottle to make up the volume lost as you dispense the soap, otherwise you'd pull a vacuum in the bottle and collapse it and/or not be able to draw any more soap.

 

[swanicyouth]

I thought the hole under the dial was the intake.

Sent from my SAMSUNG-SGH-I777 using AG Online

Could be, don't know. I only know 2 things to be true I did not know Friday:

1. If I make those threads "tight" with a pipe wrench, my MTM will eject zero soap.

2. If I "adjust" those threads on the fly while spraying foam, I find a loose "sweet spot" where the foam thickens and clings better then ever before. Also the spray pattern seems to "get more uniform" in said sweet spot.

 

[Setec Astronomy]

Oh now I see where you are talking about, in that last picture, above where you are pointing with your tool? I agree with bunky, there's no way that's "supposed" to be an air adjustment. If that is fixing your problem there is an orifice clogged somewhere.

 

[FUNX650]

I want to make sure I understand...

Prior to the disassembly...
There wasn't any Teflon tape on the brass fitting's threads (the Central Body component)...so designated by the
white arrows in the below photo...that is screwed into the Reservoir Box's cap component...so designated by "your pointer".

I'll assume these are the components that kept "backing-out" while the unit was in operation.

During/After re-assembly...There is now Teflon tape on this brass fitting's threads (the Central Body component)...as well as the other fitting's threads.
Also, all brass fittings were torqued to prevent any "backing-out-events" [and possible leaks(?)].

The very next time you fired-up the unit: No soap/foam... that is:
until you backed-out the aforementioned now-Teflon'd brass fitting (Central Body) to where a sweet-spot was eventually obtained.

It appears, to me...that the reasoning for applying Teflon tape and torqueing the Central Body component into the Reservoir Box's cap
has, essentially, been defeated by its being "backed-out" in order to locate the sweet-spot.

Either way...The Central Body and the Reservoir Box's cap must be locked-into each other to where the sweet-spot not only exists...
But also to where it can be easily re-obtained whenever disassembly is again deemed to be required.

A couple of holes in the Reservoir Box's cap, drilled and tapped for set screws, is an option.


Now...I can understand MTM's reasoning (liability) in wanting Teflon tape applied on the M22 fittings' threads (orange-ish arrows)
if one decides to not use the quick disconnects (QD's).




But since brass is a 'soft metal' it will expand readily with a little amount of heat---even the friction-heat from the foam gun solution
being whisked through the MTM system---so I usually don't Teflon tape brass-to-brass connections.
Especially to have it involved in a torqued-situation, as it were.

I'd at least remove the Teflon tape that's between the components so being discussed (probably creating some blockage);
relocate the sweet-spot; and then secure that sweet-spot-location with set screws and some Loctite.


I'd also re-do the Teflon tape on the threads on the Reservoir itself (Blue arrows).

Special Note:
The External Plastic Body/Nozzle Assembly is what creates the spray patterns;
The Adjustable Air Intake Knob is what increases/decreases the consistency of the foam (Its: thickness and cling-ness).


Of course...
I could have things bass-ackwards/be wet behind the ears.




Bob

 

[Setec Astronomy]

FUNX, you're making me a little crazy with "soft" metals therefore having a high coefficient of expansion and frictional heating from water, but you refer to an "adjustable air intake knob" which I presume is the knob on the top with the little hex-shaped part with holes drilled in it.

As I said before, the hole in the cap (as pointed to by the scribe or whatever that tool is) is to maintain consistent pressure in the bottle as the soap mix is withdrawn...this is on the upstream side of the soap and not on the downstream side where the knob and apparently the threads between the "mixer" body and the cup cap are.

These devices are pretty simply, they are using a venturi effect to draw soap out of the bottle and mix it with the passing stream of water. Normally I would say that the knob on top is controlling the amount of liquid (soap) into the passing stream (as the adjustment bar on the Gilmour does, in a step fashion, rather than a screw-adjust fashion), but FUNX is referring to it as an air adjustment, so I have to presume that something is clogged or broken in there.

I tried to go to an MTM web site but they don't seem to exist except for problem posts at various forums.

 

[FUNX650]

FUNX is referring to it as an air adjustment, so I have to presume that something is clogged or broken in there.

You'll have to excuse my Pig-Latin attempt at MTM-terminology.


I agree...There has to be a clog, something broken/out-of-whack in the Reservoir/Reservoir Box's cap/Central Body assemblies.

As I mentioned:
-I'd get rid of any Teflon tape on any fittings in these assemblies.
-I'd also inspect these now disassembled components to make sure all items/parts are accounted for. As such:

From the Reservoir "on up":
-Suction tube
-Hose 'barb"
-Reservoir Box cap
-Central Body
-A nozzle that fits inside the Central Body

From the Central Body "on up" (aka:"The Adjustable Air Intake assembly"):
-Plunger coupling (this screws into the top of the Central Body)
-Plunger
-Plunger washer
-An O-Ring
-Plunger ring nut
-Plastic knob "positioner"
-Black plastic knob
-Machine screw (to hold this assembly together)

If all of these parts are present and accounted for...
This MTM unit just may be on its way to Discovery...OOPS!!... Recovery.



Bob