Terible Boost Leak From Hole On Greddy RS

[ditchmagnet]

I am trying to do a boost leak test, but I can't even get over 2 lbs of pressure cause my Greddy RS is leaking so bad. I tightened down the spring all the way, and realized the leak was coming out of the back trough a hole that apparently is there from the factory.

What is this hole for, and how can I fix this leak? I assume it is supposed to do something.

Here is a diagram of the RS, and it seems that if the big valve was holding no air should even be getting up to that little hole on the back:

http://image.nengun.com/catalogue/original/nengun-0193-01-trust-greddy-blow_off_valve_type_rs.jpg

Thank for the help

 

[bryanwheat]

There is supposed to be a vacuum nipple in that hole for the quick release function. If pressure is leaking from that hole than you have a leak in the diaphragm.

 

[ditchmagnet]

Do I need to have the quick release set up? I am trying to find out info about it, but can't find any pics, and very limited threads about it.

Why would it leak from there if the valve is putting pressure on the opening below? Just wondering.

EDIT:

I just took it apart. The diaphragm does have a tear. That little hole doesn't have any threads though, it is just a pin hole. I still don't understand why it is leaking there. I thought the spring keeps the valve pushed down and I thought that is what sealed it?

 

[bryanwheat]

Do I need to have the quick release set up? I am trying to find out info about it, but can't find any pics, and very limited threads about it.

Why would it leak from there if the valve is putting pressure on the opening below? Just wondering.

EDIT:

I just took it apart. The diaphragm does have a tear. That little hole doesn't have any threads though, it is just a pin hole. I still don't understand why it is leaking there. I thought the spring keeps the valve pushed down and I thought that is what sealed it?

The nipple that goes into the hole isn't threaded, it is just a press fit into the hole. You don't have to have it hooked up. You are leaking boost thru the vacuum line from the intake manifold, not from the intercooler pipe into the bov. The top nipple is on one side of the diaphragm, the bottom is on the other. When there is a tear in the diaphragm pressure will leak from the top chamber thru the diagram into the bottom chamber and out the hole.

 

[ditchmagnet]

AH, OK, that makes perfect sense, I didn't realize what was happening.

The diaphragm replacement is expensive. I am looking into the bicycle tube fix right now, but the pictures on the how-to aren't available anymore.

 

[boost97gst]

+1 on the diaphram. I have that lower nipple completely open, its not supposed to leak at all. Its optional to even hook it up

 

[ditchmagnet]

And would it mess up anything if I just were to seal that little hole? Or does it relive excess pressure?

 

[bryanwheat]

AH, OK, that makes perfect sense, I didn't realize what was happening.

The diaphragm replacement is expensive. I am looking into the bicycle tube fix right now, but the pictures on the how-to aren't available anymore.

Some people have had good luck with the ngr diaphragm in the greddy bov. The ngr bov is a copy, buy they use a better designed diaphragm. They are 40 bucks for a replacement diagram. SPECIAL! - NGR Type-S Diaphragms

And would it mess up anything if I just were to seal that little hole? Or does it relive excess pressure?

The hole must be left open for the bov to operate properly. Since the bottom chamber is sealed if you seal the hole up there will be an air lock and the bov won't operate properly.

 

[ditchmagnet]

Ok, thanks for the info. I have the RS BOV, so will that one you link work? It says it is for types S, but the NGR does look like a type RS.

 

[bryanwheat]

Ok, thanks for the info. I have the RS BOV, so will that one you link work? It says it is for types S, but the NGR does look like a type RS.

According to greddy and extreme psi, they use the same diaphragm, EXTREME PSI : Your #1 Source for In Stock Performance Parts. Blow Off Valve Diaphragm - Type RZ, RS, & S

 

[ditchmagnet]

Ok, awesome. Thank a lot for your help. I'm trying to repair the diaphragm for now as a temp fix, but then I'll get that NGR diaphragm. I can't believe that greddy one is $80 though - that's insane.

 

[bryanwheat]

You might try a thin piece of rubber with some rubber cement over the crack for a temporary fix.

 

[ditchmagnet]

I'm trying to coat it in a layer of this rubber welder stuff. It is more than just a rubber tear, this thing is so worn that I can see a lot of the mesh layer.

Edit:

It didn't work. I will just have to wait till I get a new one. The rubber I tried to coat it with made it too thick and it would not seal.

 

[ZenkaiRacerDsM]

My old Type-S did the exact same thing. Fixed it with that same NGR diaphragm. When you compare the NGR diaphragm with the Greddy one in person you will see how much better the NGR one is.