mbc leaking big time help

[Norcalrallyist]

I did a leak test today and got to 2psi befor iheard some enormus leaks. They are coming from a small hole in the side of the mbc and the screw that adjusts preesure. Is it over for this mbc?

 

[91gsxboosted]

Yea if there's a hole in it I would just get a new one. You could try to patch it up, but it will probaly just leak again in the future.

 

[Pure92TSi]

That hole is probably supposed to be there. Most MBC have a small hole drilled in the side but there shouldn't be any air gettin to it until after whatever pressure you have it set at is reached. The spring in the boost controller may be extremely weak and need replaced which is cheaper than a whole new MBC. Try cranking the boost controller down some and see what happens.

 

[Norcalrallyist]

turns out air is supposed to come out of there I thought that might be the case but I dont think its supposed to come out of the adjustment screw. I took it out of the system for now im up to a whopping 4psi on the tester woo!

 

[oldman]

Step 1 when pressure testing, disconnect or turn the mbc all the way up, every mbc will do this so don't worry. The little hole you're referring to is call the wastegate pressure relief hole, without it, pressure will get trapped between the mbc and actuator/wastegate and the flapper/wastegate will not close properly.

 

[oldman]

turns out air is supposed to come out of there I thought that might be the case but I dont think its supposed to come out of the adjustment screw. I took it out of the system for now im up to a whopping 4psi on the tester woo!

Leak test aside, you're not suppose to leak out of the adjustment screw, is this a home made mbc? Ball/spring?

 

[Norcalrallyist]

I think I can fix it with some teflon tape.. This leak is the least of my problems IVe got a ton of leaks by the TB if not the TB gasket itself..... joe mbc about 2 years old though

 

[wingzgsx]

Agree! Fixing the leaks around your TB will be more beneficial (the o-rings on both sides). Check out VFAQ on how to do this. I also fixed the leaks on my MBC with teflon tape.