With D400 #1 together, I decided to go ahead and take apart D400 #2. Even with warm/soapy water bath the purge cover was a much bigger bear to take off on this one - I was nervous at times that I would break something (same for the lever adjustment screw - she had taken a real set). This one had more corrosion in it than the first one, so the air tube needed to come out. Pre-Dive switch o-ring feels more like an actual o-ring than the factory D-Ring, so I guess she has been dug into before - also the poppet was a metal unit in this one, but with a white plastic cap instead of the black one on my previous two.
ScubaPro D350 Adjustment (and soon to be overhaul)
- Thread starter aalbert
- Start date
Please register or login
Welcome to ScubaBoard, the world's largest scuba diving community. Registration is not required to read the forums, but we encourage you to join. Joining has its benefits and enables you to participate in the discussions.
Benefits of registering include
- Ability to post and comment on topics and discussions.
- A Free photo gallery to share your dive photos with the world.
- You can make this box go away
Received goodies from rsingler today, with dreary weather outside it was a perfect time for my rebuilding attempt on a D350.
Purge cover removal was easy, but the diaphragm cover did not want to twist off. After no luck with soaking and hot/cold treatments, I was able to twist it off with a rubber strap wrench. Aside from my unfamiliarity with the regulator, bit of a puzzle the first time, everything else went smooth. The lever set screw was corroded and could not be removed with hex wrench, so used vise grips to twist it out.
Reassembly went better than I was expecting, a couple times had to back up and redo since I was not familiar with the steps. Initially tried duro 90 orings on the valve body, but then realized the inlet tube had rounded edges and switched to duro 70 as indicated by rsingler.
It was helpful taking a few pictures during disassembly and paying close attention to location of the dive/predive spring on the air tube. I had no luck getting the dive switch oring to completely seat in the switch groove, so got it as close as I could and then tightened the retainer screw, letting pressure from the regulator body seat the oring. Seemed to work great since I had a square oring as replacement, not sure if that could work substituting a round oring.
One thing caught my attention and caused concern. I was expecting the spring to wind up a bit while tightening the aspirator cap. But I noticed the poppet assembly turning as I tightened the cap, and felt concern about the poppet seat being cut/damaged by the metal orifice. Is this normal or something to fix? The spring was lightly lubed on the ends, thinking about trying to sand the ends smoother and possibly adding friction reducing shim.
Everything is back together, tuned to the point of having a decent breathing regulator. The finicky nature of fine tuning the regulator is apparent now, thought I had it set perfect a few times and then back to slight free flows. But I have gained a working understanding of the regulator, now I can go back and review all the service tips and expect the fine tuning will be a success. For today, I have had enough fun.
Thanks for this thread aalbert, to rsingler for parts, and all the D series thread contributors over the years!
Purge cover removal was easy, but the diaphragm cover did not want to twist off. After no luck with soaking and hot/cold treatments, I was able to twist it off with a rubber strap wrench. Aside from my unfamiliarity with the regulator, bit of a puzzle the first time, everything else went smooth. The lever set screw was corroded and could not be removed with hex wrench, so used vise grips to twist it out.
Reassembly went better than I was expecting, a couple times had to back up and redo since I was not familiar with the steps. Initially tried duro 90 orings on the valve body, but then realized the inlet tube had rounded edges and switched to duro 70 as indicated by rsingler.
It was helpful taking a few pictures during disassembly and paying close attention to location of the dive/predive spring on the air tube. I had no luck getting the dive switch oring to completely seat in the switch groove, so got it as close as I could and then tightened the retainer screw, letting pressure from the regulator body seat the oring. Seemed to work great since I had a square oring as replacement, not sure if that could work substituting a round oring.
One thing caught my attention and caused concern. I was expecting the spring to wind up a bit while tightening the aspirator cap. But I noticed the poppet assembly turning as I tightened the cap, and felt concern about the poppet seat being cut/damaged by the metal orifice. Is this normal or something to fix? The spring was lightly lubed on the ends, thinking about trying to sand the ends smoother and possibly adding friction reducing shim.
Everything is back together, tuned to the point of having a decent breathing regulator. The finicky nature of fine tuning the regulator is apparent now, thought I had it set perfect a few times and then back to slight free flows. But I have gained a working understanding of the regulator, now I can go back and review all the service tips and expect the fine tuning will be a success. For today, I have had enough fun.
Thanks for this thread aalbert, to rsingler for parts, and all the D series thread contributors over the years!
Kupu - I have been pushing the purge button while doing adjustments to the poppet cap/spring - by doing so, the seat should be off the orifice.
Seeing your update reminded me that it has about time I put together D400 #2 , so I went ahead and did that this evening. At first I tried to use a round o-ring for the pre-dive switch, but getting it to stay in place while putting on the body proved to be a pain in the butt task - so I grabbed the one factory o-ring that I did have, and used it instead... For future units, I will have to see if I pre-mold round o-rings by soaking in hot water, placing in switch, cooling etc, and hopefully get them to set (I am open to suggestions).
The old poppet was torn up enough, that it couldn't be re-used.... I went ahead and used one of my VDH seals and tiny McMaster o-rings to rebuild the poppet (quick and easy to do), and put the unit back together.
The cover that was such a bear to take off went on smoothly when I was done. Unit has been capped off now, and lives with my other D400.... Next on the list is my spare D350.
Seeing your update reminded me that it has about time I put together D400 #2 , so I went ahead and did that this evening. At first I tried to use a round o-ring for the pre-dive switch, but getting it to stay in place while putting on the body proved to be a pain in the butt task - so I grabbed the one factory o-ring that I did have, and used it instead... For future units, I will have to see if I pre-mold round o-rings by soaking in hot water, placing in switch, cooling etc, and hopefully get them to set (I am open to suggestions).
The old poppet was torn up enough, that it couldn't be re-used.... I went ahead and used one of my VDH seals and tiny McMaster o-rings to rebuild the poppet (quick and easy to do), and put the unit back together.
The cover that was such a bear to take off went on smoothly when I was done. Unit has been capped off now, and lives with my other D400.... Next on the list is my spare D350.
Decided for the Pre-Dive switch to see if I can make a form out of Delrin, to let the o-ring take a set.. Have a scrap of 3/4" square stock coming my way, that I will trim down to match the dimensions.. Hoping a little heat/cold soak on the form for a few days will allow the o-ring to take a little bit of a set, and be easier to insert/keep in place while installing.
Similar threads
