It was installed by my mechanic as a replacement for the 21 year old factory unit that went bad. When I panic stop, aka slam the brakes, the pedal is absolutely rock hard at the top of the travel and the truck doesn't slow well at all. After it is held for what feels like an eternity (actually probably two seconds) and the pedal goes deeper into the stroke the truck does slow and it seems I have boost low in the travel of the pedal.
As the beginning of the stroke seems to be the issue, I thought this might have been an issue with the check valve that it was shipped with, so I bought a Toyota factory new check valve and grommet, but the Toyota one is way larger than the replacement valve. This actually leads me to believe that the booster which was put on the car is not a factory reman as the hole which accepts the check valve and grommet are not the same size as the Toyota factory version.
When I had the check valve which came on the reman booster off I blew some air into it to see how smooth it was and was not impressed. The Toyota version easily allows air to pass and promplty shuts when vacuum goes the wrong way. The one that came on the reman has a lot of resistance to airflow and the valve itself does not seem super compliant in shutting when, as Garth Algar may say, you go from suck to blow.
Is my line of thinking way off? O'Reilly sells a cheap plastic universal booster check valve I was considering installing to see if it helps at all.
