pro sub DX 500 scuba regulator

[rlcoker]

Does anyone have a schematic and/or a parts source for PRO SUB DX 500 scuba regulator. I have an air
leak in the second stage in a regulator that I purchased used. It has not be used in several years.

 

[jac11819]

Do you still have the pro sub DX 500 scuba regulator?

 

[LKJ]

I know this is an old thread, but I just bought a DX 500 with a Maxair I octopus and a 2 gauge Dacor console at the annual Etobicoke (Toronto) Scuba Swap for $8 Canadian. The reg is actually working OK, but I plan to rebuild it. I'v e been trying to figure out who actually manufactured it and to me it looks very much like a Tabata (aka Tusa) product, very similar (2 screw exhaust tee, 2nd stage housing shape, basic 1st stage design, disc filter with star retainer and identical dust cap) to the Ventura TR-30 with a different 2nd stage cover and clamp. The 1st stage seems a little closer to the Tusa TR-200 Liberator and an exploded diagram and parts list is available on-line. So I think that Tusa parts may very well work. I heard that Tabata made parts for older ScubaPro regulators, so maybe parts for the MK10 1st stage will work with this regulator and I'm hoping the high pressure seat is the same. The rest of the 1st stage parts are mainly just standard o-rings and possibly 1 metric o-ring. I'll know more when I get around to rebuilding it.

 

[jac11819]

Let me know how it works?

 

[LKJ]

Unfortunately, whoever last worked on my $8 regulator over-torqued everything. I managed to disassemble the DX500 2nd stage, but I could not take apart the 1st stage. After trying a wrench to remove the yoke retainer (I rounded the nut slightly), I managed to remove it using a vise on the nut instead of a wrench. However, the hp seat retainer was totally ruined by trying to remove it using a 1/4" allen socket. The hex hole in the retainer is now round. The 2 screws that hold the Maxair diaphragm/exhaust cover were torqued so much that the cover is cracked and the threaded brass inserts that the screws go into, had broken free from the holes in the plastic piece that they were mounted in.

Now for the good news. I am 99.9% certain that the DX500 is a Tabata/Tusa product. I compared the 2nd stage parts with used 2nd stage parts being sold on eBay by One_More_Chance_Scuba and the folded over demand lever tip (and other parts) is definitely a Tabata/Tusa match. The Parkway 2nd stage is an almost exact match with the only difference being different openings in the cover. It also has the same purge button lock. I measured the poppet and the seat size is the very common .267" x .08" (Trident AA88). The o-rings for the 2nd stage are a 010 and 011 for the hose, two 016s for the orifice housing and demand valve body and another 010 for the orifice. I haven't measured it yet, but the nyloc poppet nut looks like a 5-40.

So for $8 Canadian, I have a good Dacor 2 gauge console, a serviceable DX500 2nd stage and hoses in good condition. That's still pretty good.