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Hey fellas, got a problem (I think) with my tial MVS wastegate.

I took it apart to install my springs, then when I put it back together, its leaking from where the cap bolts down onto the body of the WG.

IMG_0324.jpg

Here... Ignore the fact that the screws arent tight...

IMG_0323.jpg

seems to be leaking from here... Even though that diaphragm is seated properly.

is this normal?

I blew air through the boost port with a compressor, and it doesnt even have any restriction? I doesn't seal at all!

WHATTT?

Cam/

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Sounds like your not getting enough tension. Check your spring lengths, are they the same length?

Nothing to do with spring tension, I tried bolting down the cap with and without the springs inside, and it still leaks from that surface. I don't even see how it would seal!

From what I can see the cap is supposed to bolt down and seal on the diaphragm, but it just doesn't seal!

Could I use gasket goo to seal it up?

I wouldn't [others may disagree], when I had a similar issue with my HKS WG I used a new diaphragm and that worked. But unless your diaphragm is ripped I cannot see how the WG can leak. The valve should be seated and stop all leaks. It only opens when it gets negative pressure.

^^ +1

As above, unless the diaphragm is torn, it should seal perfectly.

I would just check that when you are tighening the bolts that the diagphragm isn't being pinched (if nothing is torn).

Yeah i'm 100% sure the diaphragm isn't pinched. It's just not sealing the in the cap, so theres nothing to push open the wastegate, cos its all leaking out the gap!

Really confusing me,

It's not the exhaust part of the WG that's leaking, its the top housing that's suppose to hold boost? I'm blowing into the boost source with my mouth and it pushes up the valve with no spring in it, but the air is escaping from where the cap bolts down...

Maybe heat has distorted it, long shot. Try checking it for true. A lathe would be handy otherwise plate glass and steel rule.

It's a brand new gate, straight from the box...

I'll take it to a workshop and see what they think.

Try fitting it together without the diaphragm and see what is stopping it from going together tight. U need to measure the gap (crush) that the mating surfaces have and then

Measure the thickness of the diaphragm.

This should tell u if there is a design issue.

There must be something stopping it in between the surfaces

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