Boost leak at IC to TB hose

E.Murray

E.Murray

Donating Member
In chasing poor boost control, I came across the bicycle inner tube trick to pressurize the intake. It works great for a $4.59 total cost. Very slick!
When I give it more than 5-10 psi, I can hear air hissing from the short tube from the upper IC to the throttle body. The pressure leaks fully from 20 psi is less than 2 seconds. I sprayed soapy water and can see bubbles from both ends of the hose. Even cranking the hose clamps down as hard as I could didn't fix it. It seems to me that the design isn't great since the clamps tend to squeeze very tightly on the sides (the "pointy" part) and not so much in the flatter area, which is where I'm leaking. The hose isn't on the ears on the throttle body and I tried moving the clamps back and forth, with no improvement.
The hose seems to be in good condition, so I don't know that a new one would do better. What options are there for holding pressure? A better clamp design? Some way to get a more positive seal? I searched and didn't find anything useful, but I can't be the only one who's dealt with this problem...
 
sytyguy

sytyguy

Moderated User
Re: Boost leak at IC to TB hose

A local guy had a similar issue and he siliconed the hose in place and ran aftermarket clamps. I've personally never had an issue there, but I run aftermarket clamps and have a painted upper IC and TB so the hose has a little more material to bite to.
 
E.Murray

E.Murray

Donating Member
Re: Boost leak at IC to TB hose

"Aftermarket clamps" meaning something different from the standard worm gear style? Silicone was the first thing that popped into my head, but I didn't know if that was big no-no. I assume I need to take the upper IC completely off to get the hose off?
Thanks.
 
sytyguy

sytyguy

Moderated User
Re: Boost leak at IC to TB hose

E.Murray said:
"Aftermarket clamps" meaning something different from the standard worm gear style?
Click to expand...
Un-huh.....aftermarket....not stock for the application. Specifically, T-bolt clamps, SL T-Bolts, Norma, etc....
E.Murray said:
I assume I need to take the upper IC completely off to get the hose off?
Click to expand...
Not all the way. Loosen the outer brackets at the manifold and the middle bracket at the IC and rock it back.
 
Jimmy

Jimmy

Banned
Re: Boost leak at IC to TB hose

E.Murray said:
In chasing poor boost control, I came across the bicycle inner tube trick to pressurize the intake. It works great for a $4.59 total cost. Very slick!
When I give it more than 5-10 psi, I can hear air hissing from the short tube from the upper IC to the throttle body. The pressure leaks fully from 20 psi is less than 2 seconds. I sprayed soapy water and can see bubbles from both ends of the hose. Even cranking the hose clamps down as hard as I could didn't fix it. It seems to me that the design isn't great since the clamps tend to squeeze very tightly on the sides (the "pointy" part) and not so much in the flatter area, which is where I'm leaking. The hose isn't on the ears on the throttle body and I tried moving the clamps back and forth, with no improvement.
The hose seems to be in good condition, so I don't know that a new one would do better. What options are there for holding pressure? A better clamp design? Some way to get a more positive seal? I searched and didn't find anything useful, but I can't be the only one who's dealt with this problem...
Click to expand...

Does your upper IC have all three support brackets in place? (Somebody please post up the service manual diagram for the brackets.)

There "should" be a straight bracket off one of the #2 exhaust manifold bolts,a curved one off one of the #6 manifold bolts, and a Z shaped bracket that attatches the IC to the intake manifold.

All of them attach to the bottom of the IC tank.
 
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