Scubapro S600 Classic Demand Lever Issue

[nikolay_zhelev]

Hi guys,

Last week I discovered very strange issue with my recently purchased second hand Scubapro S600 Classic.

When I press the demand lever fully down (purged) the top of the demand lever effort arm catches the guide sleeve of cracking effort adjustment knob.

This is a serious issue, because there is a risk of lever blockage in fully down position, which will result in free flow and huge gas loss and needs to be rectified before next dive.

It took me quite a while to figure out where the root of this issue is. Initially I thought that wrong guide sleeve could have been installed, but fortunately I had a fully working S600 and I managed to compare both regulators. It is the correct guide sleeve. No issue there.

Another possible problematic area could be the lever tabs (the lever load arm) blocking or interfering in the air barrel broached holes. I disassembled the S600 Classic and inspected thoroughly the broached holes, but I couldn't locate any issue there.

Next thing I did was to remove the lever suspecting bended or deformed demand lever but as you can see below the lever is in perfect shape.

I started comparing my defective S600 Classic with my functional S600 side by side and there is a visible demand lever length difference between the two regulators with the defective S600 Classic having longer demand lever.



I compared the dimensions of the defective lever with perfectly working S600 lever and I found the source of the problem: the defective lever has 14 mm feet length, but the working lever of my other S600 has 13 mm feet length.

I will order a new demand lever according to the S600 Classic diagram, but in the meantime I’m wondering how this happened?

Are you aware of different demand lever lengths despite their identical look?

Also do you know if the metal barrel upgrade kit of Scubapro comes with lever or just the barrel?

I hope this will be interesting topic.

All the best!

 

[rsingler]

Very frightening prospect - having the lever lock down as appears to happen momentarily in your first video!
I'll be interested in the thoughts on this problem.

 

[lexvil]

In my opinion it the “feet” on the other end of the lever.

the adjuster “assembly” on the problem looks home made, which may be why it interferes with the lever, just guessing but I know you have some innovative craftsmen in your part of the world, at least there were when I was there.

 

[nikolay_zhelev]

Hi guys,

Thanks for following the topic.

The top of the demand lever effort arm I call "feet". I might use wrong technical term, so feel free to correct me if I'm wrong, however I put pictures for better understanding.

@lexvil there is some innovative craftsmen here indeed, but this regulator comes from UK
Which part do you call the adjuster "assembly"?

All the best!

 

[lexvil]

This is the “adjustment“ part

this one is assembled

and this is the metal barrel assembly.

I feel that yours was a ”home shop” conversion of an S500 or 555, I don’t know for sure obviously but a close up picture of the adjuster on you problem regulator would help.

 

[nikolay_zhelev]

Thanks for the pictures lexvil.

The defective regulator is S600 Classic - it has different look comparing to the regular S600 and one difference is the cracking effort adjustment knob. Initially I tought like you - it's something "home made", but once I checked the schematic - that's how it looks and I like it

The diagram breakdown below shows more details on the difference - it's assembly No 37 that is different, the rest is the same on the adjustment side.

Thanks for the metal barrel photo. What is the metal barrel kit P/N?

Unfortunately I can't clearly see if the lever is in the box, can you please re-confirm that?

Here is another view of my S600 Classic barrel assembly:

All the best.

 

[lexvil]

Nice, it looks like they used a G260 adjuster. The Metal barrel assembly is # 11.602.020
no lever is included.

a simple test of you theory is to make some relief cuts where it looks like the parts are sticking or switch levers between the regulators and see if that helps.

 

[halocline]

If there really is a 1 mm difference in the length of the lever, that's quite a bit. Seems like your regulator, for whatever reason, has the wrong lever. There have been many generations of those SP levers, some with pretty significant differences. I have had to swap levers around in the old metal case 109/balanced adjustables to get them to operate smoothly and sit at the optimum height when closed. Nice to see the issue still exists with the newer, needlessly complicated 2nd stages as well!

 

[scrane]

In a diving situation, is it possible for the diaphragm to have enough range to push the lever into that fully retracted/jammed position?

 

[nikolay_zhelev]

Hi guys,

Quick update to the topic.

Today I received a genuine Scubapro replacement lever and I can confirm that the root cause of this problem is difference in length between the installed and the applicable to this model demand lever. The photo below shows both levers side by side.

I hope this topic will be helpful to all of you.

If anyone finds another second stage with this issue, please update the topic. I'll be very interested if there are other regulators with this problem.

Safe diving.