How many dives between D400 servicing?

[ericpitar]

Hello,

What is the recommended interval (timewise or divewise) for servicing D300/D350/D400? How many dives have D300/D350/D400 owners out there done between servicings without experiencing problems rooted to skipping service?

E

 

[Isaac-1]

There was a time in the early 90's when I was instructing for a high volume low dollars shop that I was probably in the water (confined water or cert dives) at least 10-12 hours per week from mid march through mid sept, and probably averaging 3-5 hours per week the rest of the year, once you add in personal dives, and a slower pace of classes. Count the number of dives however you want, remember over half that was in chlorinated pools. At the time I used a Mk 10 / D300 it would go months without drying out and it was never serviced more than once per year and never had a problem.

Ike

 

[ericpitar]

Thanks for the quick reply Ike....And chlorinated pools do more damage than salt water, am I correct?

I've seen the D350/D400 kit and it appears the seat is likely the first part to wear. The rest look like they could last a while. Has anyone out there just replaced the seat and cleaned/lubed the rest when servicing? If so, how long/how many dives did that last?

 

[Isaac-1]

I would hate to use the term "more damage" it is probably a matter of different damage, level of metal corrosion vs. failure rates of rubber parts. The poppet assembly (which includes the seat, stem, and a couple of o-rings) is the main part of the D series service kit, if I recall correctly at one time it was the only thing included in the service kit, since then they have added a few other dynamic o-rings (the swivel and one behind the switch for example) as well as the lever set screw (it seems like the original lever set screw service advice involved locktite, I am not sure if that was official, but I know I have seen plenty with locktite residue) . Everything else is lube and replace as needed.

p.s. I am up and can't sleep,...

 

[DA Aquamaster]

The seat is the part most subject to wear.

D400 service does basically invovle only cleaning and seat replacement. The hose swivel o-ring gets replaced as well and while a new set screw is included, replacing it is partly insurance against having the old one corrode in place and partly an issue of restoring the bearing surface for the lever. They come with locktite on them.

Replacing the gasket under the dive/pre-dive switch is a major pita and there is no real reason to do it unless it is worn.

Spring pressure is very low in the D series center balanced design so seats tend to last a long time both in terms of storage an in terms of use. I used to run mine till they dropped (reg techs usually work on OTHER peoples regs) and 3-4 years with 100-130 dives per year was not uncommon before D400 said enough was enough.

I would not however let one go that long unserviced in salt water as there are a couple parts that could corode and become permanently attached to each other in that time span.

 

[ericpitar]

The seat is the part most subject to wear.

D400 service does basically invovle only cleaning and seat replacement.

Does this mean that, typically, only the seat, hose swivel o-ring, and set screw in the "annual repair kit" will get used in the annual recommended servicing, while the rest (such as the poppet and dive switch gasket) "only if damaged"? Are each of these parts, such as the seat, available individualy or do they always come in a "kit"?

 

[ericpitar]

Aside from freeflowing, what is the D400's way of saying "enough is enough, take me to service"?

 

[Isaac-1]

From what I have seen, the biggest "silent killer" of D series regulators is probably corroded lever set screws. The problem is once they are frozen in place, they can become impossible to remove without causing major damage. Sometimes extended time in an ultra sonic cleaner helps, but sometimes you just have to give up and replace all the guts.

Ike

 

[DA Aquamaster]

The older kits had separate seats, poppets and poppet o-rings. The new ones come with a poppet assembly. Replace the whole assembly and it is covered.

The only thing that does not get routinely replaced is the gasket for the switch. If it moves freely with an appropriate amount of resistance (ie not too loose and not too sticky) and passes a vacuum check, I don't see the need to replace it. In practice they last several years.

I agree the big killer is the frozen set screw - it is one of the parts that lieks to permantly bond with another part - the aspirator body. It is a major reason to replace it annually. A new aspirator body has a dealer cost in the $50 plus range and then you need an orifice as the new ones use a separate orifice (and do not perform as well as the old ones) so it gets very cost prohibitive to fix what appears to be a small problem - and it assumes you can get a new aspirator body, which will not always be the case as the D series gets older.

I encountered a reg with exactly this problem last week. The hex end of the screw has very thin walls and will split making it virtually impossible to remove or even adjust.

 

[DA Aquamaster]

Aside from freeflowing, what is the D400's way of saying "enough is enough, take me to service"?

As a seating groove gets to deep you will note the need to readjust the reg to stop a slight freeflow. When that occurs (other than after initial break in if the need arose) don't bother adjusting, just service it as it will usually continue to need adjustment every few dives and after a few adjustments will not stop leaking at all.