Leaky Throtle Body and RTV

[Crazyjoker77]

okay so i did a boost leak test and my only leak is at my throttle body both where my dejon elbow connects and where the TB meets the intake manifold there are gaskets in there but no matter how much i torque down the bolts it still leaks.(also I AM using the shorter 13mm bolts that dejon suplies with there IC pipes) now i already have 1 gasket on both sides of the TB but it still leaks so I went out and bought a tube of copper RTV silicone but i have never used this stuff before. would it be best that i use it on both sides of the old gasket and reinstall or just put the RTV on the both sides of the TB and throw the gaskets out and bolt it all back together. also how long should i wait before i try to pressure test it. Also i have a leak coming out of my BISS screw is there a easy fix for that.

 

[chicagoavenger]

it's probably the seals inside the Tb http://www.ca.dsm.org/faq/tb-shaftseals.html

 

[ROOKIE1]

There are o-rings on throttle plate , inside throttle body , that could be leaking . Also there is an o-ring on biss that could be missing or dry rotted .

 

[daren_p]

You sound pretty sure but it is leaking at the throttlebody to ic pipe gasket and not the tb shaft seals? To tell if its the shaft seals, move the throttle plate open and closed while doing a boost leak test & the pitch of the leak will change. As for using the RTV, when I did mine I just put a thin layer on both sides of the gasket (but only on the outer gasket, not the inner tb to intake mani). As for the BISS screw it probably the BISS oring thats damaged, dried up etc. & leaking. Go get a new BISS oring for a dealer & that should solve your problem. Do you still have the BISS cap or is this missing? If this is missing pick one of these up as well. The orings tend to get damaged alot easier/faster without the cap installed.

 

[Crazyjoker77]

You sound pretty sure but it is leaking at the throttlebody to ic pipe gasket and not the tb shaft seals? To tell if its the shaft seals, move the throttle plate open and closed while doing a boost leak test & the pitch of the leak will change. As for using the RTV, when I did mine I just put a thin layer on both sides of the gasket (but only on the outer gasket, not the inner tb to intake mani). As for the BISS screw it probably the BISS oring thats damaged, dried up etc. & leaking. Go get a new BISS oring for a dealer & that should solve your problem. Do you still have the BISS cap or is this missing? If this is missing pick one of these up as well. The orings tend to get damaged alot easier/faster without the cap installed.

okay i did the test a few more times and used soapy water. bubles formed at the BISS screw and on the sides of the TB elbow flange. When i move the throttle body the sound does not change even at 30psi so i think my shaft seals are okay just my biss screw and i need a better gasket for my TB elbow so can i just put RTV on both sides of the existing gasket and throw it back on. Also how long should i let the RTV cure???

 

[zippyshoe]

I would recommend buying a new set of throttle body gaskets and BISS o-ring. Gaskets are fairly cheap and should fix your boost leaks. With a new set of gaskets, no RTV should be necessary to get a good seal. When you replace your gaskets, you may want to check the mating surfaces of your throttle body elbow, throttle body, and intake manifold for any significant damage such as large scratches that would prevent a good seal. Hope this helps!

 

[daren_p]

What outer tb gasket do you have? If you still have the factory one like the one that was on my car, thin black plastic gasket, then that could be your problem. Order a new one from Mitsu or get it from a dsm shop. It will be more of a paper that is blue/green in colour and has a ring of green sealent around it. When I installed mine I put a thin layer of RTV on both sides just to make sure it wouldn't leak & it holds perfect. As for drying, Im not to sure, might say on the package? I left mine overnight before I drove it and it was fine (did a boost leak test after I drove it, when had time)

The gasket style should look like this, but they obviiously have the inner pictured.

http://www.slowboyracing.com/more.php?id=1935&

 

[Crazyjoker77]

What outer tb gasket do you have? If you still have the factory one like the one that was on my car, thin black plastic gasket, then that could be your problem. Order a new one from Mitsu or get it from a dsm shop. It will be more of a paper that is blue/green in colour and has a ring of green sealent around it. When I installed mine I put a thin layer of RTV on both sides just to make sure it wouldn't leak & it holds perfect. As for drying, Im not to sure, might say on the package? I left mine overnight before I drove it and it was fine (did a boost leak test after I drove it, when had time)

The gasket style should look like this, but they obviiously have the inner pictured.

http://www.slowboyracing.com/more.php?id=1935&

Hi well i think you solved my problem my outer gasket is that cheap very thing plastic material so im gonna order those but i still need the o ring for the biss screw where can i find one of them we dont have a dealer near where i live.