Motive ProductsMotive Products 1111 1st Gen and 2nd Gen Miata Compatible 70mm Threaded Adapter, Compatible Power Bleeder Attachments

I think it works great, but the catch is that before using this teflon tape should be wrapped around the threads of the brake or clutch master cylinder you're using it on, and to keep threads as free as possible from any thing that would compromise the grip on the threads (e.g. brake fluid). The teflon tape gives a better seal that the hard plastic threads on the cylinder so should the threads be slightly worn the adapter would stay nice and tight due to the tape. Make sure to always use the black circular rubber insert as that also helps create a seal. I believe this flaw is more of a metal adapter onto a plastic master cylinder thing rather than an poorly designed flaw. I'm not sure off the top of my head how Motive could improve the adapter while keeping it durable and easy to use.Common sense, but ensure you do not cross thread the master cylinder while screwing on the adapter. Go slow and go easy with applying pressure with the pump, and go slow when unscrewing the adapter to release pressure.The swivel that comes on the metal adapter makes it so much more easier to work with than the plastic adapters that don't have a swivel.I find the best method is to:Drain the cylinder of fluid by using a syringe, pump, a turkey baster, or something similar.Pour in the new and fresh brake fluid to the full line,Screw on the adapter and attach that to the pump,Loosen up the bleeder valve, but keep it lightly snug so no air gets in. (this way you can easily open the valve under pressure for bleeding)Attach an appropriately sized hose to that valve that loops up before it comes down (air rises up so this will ensure that air won't be sucked back in)Set the pressure on the pump to Motive's recommended specificationRelease the valve until the fluid is clean and free of air.This is a method I've learned from other users. It's cleaner and easier to clean than directly pouring brake fluid into the Motive pump's reservoir.

Fits most NA/NB Miata brake reservoirs, and allows a 4-corner brake bleed in about 10 minutes.The cap is high quality, and the swivel fitting is very nice to have as it keeps the hose untangled.I was able to seal and pressurize to 10psi with no issues, and bleed all 4 calipers in about 10 minutes.I would suggest NOT filling the Motive pressure bleeder with any fluid, just pressurized air, and keep an eye on the reservoir to make sure it doesn't go empty. Pump up to 8-10 psi, put a clear hose on a caliper's bleeder and open it up -- close when only clear brake fluid comes out. Check the reservoir and go to the next caliper until you've done them all. You're finished!

It fit my 2001 Miata. It's the metal cap and attaches to the Motive supply tube via a brass fitting.

Great adapter from motive made of aluminum so will hold up better then the plastic ones

Good seal, no leaks, makes pressure bleeding an easy one-person job.

Works ok, but the miata reservoir is kind of flimsy at the top...so took a few tries to get a good seal.

Fits perfectly to the base Motive pump.

Worked great for my 1990 Miata!