Don't try my code above - that was an example of what could be causing your problem. Instead, you should have code like this:
Code:
If (pressureSwitch)
{
Relay.set(kForward);
}
Else
{
Relay.set(kOff);
}
Note the difference between this and the code I posted above - above, the code would stop it, then start it every single time we read the value of the pressure switch. With this code, it will either star it or stop it, but can never do both at once.