ChevyKiller

I wanted to replace my manual trans brake valve body cause my transbrake had a couple second delay. The unit that was in my Art Car trans was poorly made IMO as it seemed they just cheaply modified a stock plate. I ordered a PA (Performance Automatic) trans brake valve body cause PA has a good reputation of making some of the best high performance trans parts.

The PA valve body looked light years ahead of the art car. It was a complete custom plate with numerous more cuts and paths for high flow.

The one thing I noticed immediately was my Art Car valve body and several others I have seen for C4's and AOD's had placed the TB/Line pressure valve wide open at all times by using some sort of clip to hold it full open all the time. This keeps full line pressure at all times in the trans.

The PA valve body didn't have any such clip and the TB/Line pressure valve was closed and I didn't understand how it would open and allow full line pressure when you went WOT.

I went to PA's website and watched the instruction video....(Warning it's huge and almost 90 mb)

http://www.performanceautomatic.com/videos/aodvbs.wmv

Here are the instructions also were no referrence is made anywhere about the TB/Line pressure valve...

Attachment 31762

Now in the end of the vid, you can clearly see/hear where they say you don't need to do anything with the TB/Line pressure valve. I thought this was very strange so I called them TWICE and spoke o them about it. They explained to me that the paths allowed for the trans fluid to push open the TB/Line pressure valve when under WOT.

Now that still seemed wrong to me (I am no expert at all) because I just couldn't see how the pressure would open the valve all the way. It seemed to me the valve would only open enough to allow any kind of flow or line pressure. PA ASSURED ME that thier design didn't require clipping or placing the TB/Line pressure valve full open at all times was neccessary. The were adamant that the flow and paths would do it automatically when needed. This still seemed wrong to me (and my transmission guy Tony) but they are the 'experts' and it is there product so we put it on as told.

Now, imagine my suprise when after install, I drove the car 10 MILES and then the trans smoked!!!

The sprag smoked, all the second gear clutches and frictions smoked, and this was within 10 MILES and FIFTEEN MINUTES!!!

I call PA and they again tell me that they have cuts to allow flow to open the TB/Line pressure valve when needed at WOT. We pull the trans a part, and low and behold there is NO SUCH CUTS OR PATHS TO ALLOW ANY KIND OF FLOW TO OPEN THE VALVE!!

The PA valve body is still a great piece but this is a MAJOR FLAW that is nowhere addressed by them in any of their instructions, personal support, or instalation videos but it is a FACT that the TB/Line pressure valve needs to clipped or pinned back to allow full line pressure or you will not have full line pressure ever in your trans. It is a really crappy deal, cause it allows a little pressure which is worse than no pressure at all because with no pressure at all, you'll know it instantly before you do any damage. The real crappy part is you get just enough line pressure to thinnk the trasn is working fine and then you'll smoke it on your test drive almost instantly when you go WOT.

This post is a combination of a rant, warning, and question to others familiar with transmissions of they have ever heard of any valve bodies that work like PA exlpains there's is supposed to. I personally have never seen one (on a full manual trans) that works as they describe. I have always seen the TB/Line pressure valve pinned or clipped open at all times.

Any feedback is appreciated.