Do Proportioning Valves Wear Out?
Its brakes ! Damn people :( I hate to loose my religion on Sunday morning but...
Here's the very first thing one is taught in brake school. "Everyone is better off with a vehicle that wont go than a vehicle that wont stop".
To the thread starter... You haven't questioned reusing the master cylinder, wheel cylinders, fluid lines, from the donor. Apparently you are renewing those.
I wont ask why the proportion valve isn't considered the same.
Do this for us... Look in any factory service manual for instructions on servicing a proportion valve. You will find only that it is not to be serviced.
I'm sure your next question is, "So why does someone build and offer a kit with instructions ?" Short answer is "If you build it they will come".
Better answer is, The same reason someone built a solid state regulator and then told owners all they needed to do was bend a little thingy. They want your money and nothing more.
The internet is like a horse stable. The chit is dropped there to stay. No way to clean it up. Anyone who wishes to dance in the chit need only to google or ask in a public forum for the appropriate tune and dance steps.
For 6 years I have taken others by the hand and led them safely and quietly around all the chit. They came out the other end of the stable to carry on, nothing less than happy moparing ahead. That was/is my only goal. It stems from love for these cars and their owners, not pictures of dead presidents.
Now ending this sermon
You have 2 options, forget you ever started this thread and buy a new proportion valve or.... dance.
Yes, its brakes. And I too have jumped on the soapbox a time or two (ok, maybe even more than that) regarding brakes. But if you use that standard to the absolute level, then you should replace every single component involved with braking every single time you buy a used car regardless of its operational status, mileage, etc. After all, those brake parts are
used. :shock:
Or you could apply some logic, sound reasoning, and even some scientific method instead of just jumping on the soap box.
Its an extremely simple part. Yes, it has a couple of moving pistons and some seals. But if it doesn't leak, and fluid goes in the input and comes out of the outputs, the worst thing that can happen is the proportioning balance is off. Which is pretty easy to test (and you SHOULD test it). And it CAN be adjusted using the proper bleeding procedure, which re-centers the prop valve
if its working properly.
So seriously, if it doesn't leak and isn't plugged, test to make sure the proportioning is fairly well balanced and run it. You're way better off running a used proportioning valve than you are buying a rebuilt master cylinder- the latter may have been sleeved incorrectly, not sleeved if it needed it, rebuilt multiple times, and not tested once it was "rebuilt". I've had far more problems with "reconditioned" master cylinders than I have with untouched prop valves.
Just because something is "new" doesn't mean its good, and just because something is "used" doesn't mean its bad. This is especially true now, with the quality control of new parts being somewhat questionable in many cases.