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throttle body shaft seals question

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GettinPaper

10+ Year Contributor
289
0
Aug 31, 2009
Battle Ground, Washington
I replaced every gasket on my throttle body other then my shaft seals because of this damn boost leak around the throttle body, i was reading that the auto parts store seals don't fit as well as OEM.. is this true?? Or is it okay to go down to the auto parts store and buy some?? Any help is appreciated thanks..
 
I replaced every gasket on my throttle body other then my shaft seals because of this damn boost leak around the throttle body, i was reading that the auto parts store seals don't fit as well as OEM.. is this true?? Or is it okay to go down to the auto parts store and buy some?? Any help is appreciated thanks..

Hey man, can you please update when you get this done? I have a boost leak at the TB as well and is in my to do list. What kind of symptoms did you have? My car idles high sometimes, when I push the accelerator cable closed manually by hand at the TB it goes back to normal. I also get a Check engine light but if a clear it it'll take a couple of months for it to come back. It says its from running rich or lean so I'm hoping I will do the TB seals on a weekend sometime soon. Any tips are appreciated
 
Hey man, can you please update when you get this done? I have a boost leak at the TB as well and is in my to do list. What kind of symptoms did you have? My car idles high sometimes, when I push the accelerator cable closed manually by hand at the TB it goes back to normal. I also get a Check engine light but if a clear it it'll take a couple of months for it to come back. It says its from running rich or lean so I'm hoping I will do the TB seals on a weekend sometime soon. Any tips are appreciated

I could be wrong, but then again I have a leaking TB also. My car idles fine and it doesnt effect nothing at all. By manually closing the TB do you mean its staying open/stuck?
 
it feels like it stays very slightly open. Maybe my cable needs adjusting. But it only does it sometimes, so it makes me think it could be the tb leak. Is yours pretty big? mine wont hold 15 psi for very long. Maybe 5 to 7 seconds.
 
It could either be the throttle cable or the SAS screw that's holding the throttle plate open.

When doing a BLT, have you sprayed the throttle body with soapy water to see where the leak is actually coming from, if you have one in that area?

Yes, now that you mention it that's the weird thing. I did a BLT and air came from around the t-body. I couldn't pin point it and I did the soapy water, I couldn't see any obvious bubbles coming out. This seemed weird, so I did a smoke test with a cigar. blew about 3/4 of a cigar into the turbocharger inlet through a little hose with my Boost Leak Tester. When I pressurized the system again, filled with smoke, I could hear the boost leak, but I couldn't see any smoke coming out. I just assumed it evaporated? I know weird. But searched a throttle body Boost Leak and I just assumed it was that because it seems just like mine. Do you think it could just be my throttle plate not closing all the way and all that smoke I blew could have just gone into the manifold?
 
If you're unsure if the plate is closing the whole way, take off the upper intercooler pipe and look at the plate. Then you can see if it's sitting slightly open or if it is indeed closed. If slightly open, but you can't push the throttle cable bracket anymore to close it, then the SAS screw is out of adjustment. If you can push the throttle cable bracket closed more, then the throttle cable isn't adjusted properly. If both of those aren't the case, then you either have leaky shaft seals (should see bubbles from under the springs) or the gaskets for the throttle body aren't fully sealed.
 
If you're unsure if the plate is closing the whole way, take off the upper intercooler pipe and look at the plate. Then you can see if it's sitting slightly open or if it is indeed closed. If slightly open, but you can't push the throttle cable bracket anymore to close it, then the SAS screw is out of adjustment. If you can push the throttle cable bracket closed more, then the throttle cable isn't adjusted properly. If both of those aren't the case, then you either have leaky shaft seals (should see bubbles from under the springs) or the gaskets for the throttle body aren't fully sealed.

thanks for the info. I'll check into it ### it hasn't gave me the best gas mileage
 
After a recent BLT I too had leaking shaft seals. I sent my entire TB to Steve Monroe at Throttlebodys.Com For a very reasonable price he does a complete TB tear down, rebuild, TB seal replacement, gaskets etc. Great communication and very fast turnaround time. For the $$ it was worth what looks to be somewhat of a PITA dealing with the TB teardown, TB cable return spring installation hassle and everything else.
 
i've had a few problems and popped off the TB so many times i am sick of buying new OEM gasket every time.

i bought some rubber gasket material traced out the old gasket punched some holes, ( used a old cheap socket the correct size grind the edge sharp and use to punch out the holes)

then use Permatex® Aviation Form-A-Gasket® No. 3 Sealant Liquid. this stuff is black goo and is awesome never had a leak.

if you have a BBK TB you will no that the bearings will leak apply this around the edge of the bearing on the shaft under the bearing and no leaks!
 
Thank you very much!! It looks pretty straightforward, I don't think I can mess it up. I'll have an extra set of hands so I'll ###### have them just hold the return spring how it was when i take it off while replacing the seals to make It easy.
 
The hardest part will be getting the screws out of the shaft. The return spring can be tricky just mark everything prior to removal with a sharpie or something. Make sure you also mark the plates orientation as having it the wrong way can ncause the throttle to stick/not close fully.
 
A couple tips, I usually drill out the heads of the 5 screws on the bottom portion of the T/b, (just use a bit larger than the threaded portion, and they will come right off) and then they will turn out easy with a pair of pliers. Take the lower section to the hardware and get the same thread pitch and length in allen head bolts. They are a lot easier to remove next time.

Also, When I remove the screws in the plate itself, I like to put the body in a vice with a rag around it to keep from scarring it up. Get a screwdriver that is the EXACT SIZE for the screws. This is very important, you want the most surface contact that you can get. Now grip the screwdriver shank with a pair of vice grips, and turn it with the vice grips while firmly pressing down on the screwdriver with your other palm. (using a little heat on the back of the shaft helps too) Very rarely do I have any trouble with this method, and you can usually loctite and reuse the screws.

Hope that helps someone.

I vote Oem seals all the way. Mine leak tested to 50 psi even after a few thousand hard miles.
 
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