So I've been looking into getting a Motive Power Bleeder and the only one that works for Honda's is universal. The have been mulitiple reports of the universal cap not having a good seal.

So my thought is get a MC cap and put a 1/4 threaded fitting in it and use that instead to get a good seal. My question is can the cap handle pressures up to 15psi w/o leaking?

I've searched and no one has done this.

 

You don't need that much pressure.
9 or so will do it.

 

For the OEM master cylinder cap?