Why is my almost new Tial wastegate leaking??
 

Did some testing with the MityVac and it won't hold any pressure. I can jack it up to 15-17psi but it just bleeds right off to zero within a few seconds... I ended putting the bottom part in water and sure enough it's leaking through the inside valve stem...

I pressurized the top part (which is normally open to atmosphere) and it holds steady up to 30psi

I remember testing it months back before I had installed it and I had the same results... but it hit me today that this might be the cause of my boost creep to 17psi. I have a 13psi spring in there...

Is this normal? Has anyone ever tested a Tial before?

At Az Rotary Rockets we use a tone of Tial waste gates and BOVs and I have only seen one with this issue, turned out it was fake Jrat got from a shop a long time ago. The bov was identical to a real one yet had no serial number on top. They should have Tial and a serial number machined into the top.

Tial is some of the highest quality I have used, so I would be suprised this was a real one, however if it is call tial they will work with you.

Just checked and it has the name and serial number on the top, it also says "Made in USA". The bottom section has Tial engraved.

I bought this brand new with my turbo kit last year from A-spec.

Don't worry mate. Your wastegate is fine. All external wastegates do not hold pressure if applied to the bottom port as there is always a small leak past the valve. However they should always hold pressure on the top port (unless the diaphragm has a hole in it).

Because the bottom port always leaks, the easiest way to test your wastegate for correct operation is to use an air compressor with an adjustable pressure regulator. Run a vacuum line from the compressor to the bottom port of the wastegate. Tee an accurate pressure/boost gauge into this line so you can see the pressure being applied. Then slowly increase the pressure by adjusting the regulator until the valve lifts. Find the pressure where the valve starts to open. Then find the pressure where the valve is fully open. On most good quality wastegates the valve will go from lift off to fully open within a short range (say 3-4psi) I have seen some nasty Chinese knock offs that take like 10psi to go from lift off to fully open. I have also seen knock offs that do not open as far as the original. In practice the boost you will get when running just on the wastegate spring (no boost controller) will be somewhere between the crack off pressure and the fully open pressure provided your wastegate flows enough to control boost.

try this.
Line out from the compressor that goes into the boost conttoler, "T" it off and connect that to the side wastegate, then the line out from the boost controoler run that to the top of the wastegate. Worked for me, i was getting mass boost creep but fixed my problem, im even runing dual tial wastegate.

Yeah, for some reason I thought you wer talking BOV's...sorry

Yeah the side port on my 38mm holds but it is not a problem if the side leaks down,,,

Thanks for the info guys...

Wow, you made me feel a lot better. I got my Tial 38mm a couple days ago, and I did a few tests to see if the seal on the bottom "plunger" was tight. I noticed right off the bat that I could see light between the pluger and the housing. This worried me. I put a few drops of water on the bottom of the WG, and held it upside down and sure enough water dripped past. Should I be worried at all?