brake proportioning valve question

The rubber part on the bottom of the valve is slightly torn and so it's leaking fluid. I went to the dealer to see how much it is and they quoted me a price for the valve. But, when I looked online, I saw a couple of pics of new ones just out of the box and they did not have the rubber part on the bottom.
Is the rubber part separate from the valve and can I just purchase that by itself? The valve is $200 and I can't find any aftermarket ones.

 

bump.. just an update. It seems that the rubber boot is a seperate part from the proportionate valve and it's only $50.

 

All the rubber boot does is keep dirt and water out. It isn't a seal. If the valve is leaking you will have to replace it. The boot won't fix it.

 

Thanks, for some reason I was thinking the boot held fluid. so, I should replace both, then.

 

Yup.