Dump valve leaks?

Hi all,

In preparation for using our new (to us) TM, I installed a new Thetford (the prior owner had removed it).

Filled it up with plain water to test for leaks. Had both the outside dump valve and the toilet dump valve closed. As a test, I opened the toilet valve (as you would do if you were planning to close the unit and drive to the dump station). The outside dump valve did not provide a 100% seal - there was a very small trickle. As far as I could tell, it was completely closed.

This doesn't matter with clean water, but would not be good with the normal contents.

In addition to the leak, the slide moves VERY stiffly. Anyone have ideas on either issue??

Thanks,

Steve