Now if I were to take it into another shop and they give me a run-around, should I just specify to them to change the modulator if it's cheap enough to start out with? Apparently the part itself is like $70, and then with labor it wouldn't be too expensive. Probably a little cheaper than having the filter and fluid changed and I think the chances of it being the modulator over the filter are pretty high. If that doesn't work then they'll probably have to tear in and check the seals but I'd rather eliminate an external possibility that's cheaper than have internal seals checked with high expense to find out there's no problem. Is there perhaps a way to test this modulator?