eniac

Anyone else here running over 27 psi boost? Does your throttle body start leaking around 23 psi? I have resealed mine 3 times, also I have tried 4 other stock TB's yet all of them seem to start leaking around the seals.

Is there any fix for this or will I have to suck it up and machine an adapter for some aftermarket TB to fit?

special tool

How much is it leaking?
Its good to be vigilant with leaks, but probably you are being a little cuckoo with this one, dude.

eniac

You are correct it's not leaking much but I'm concerned the leak will get worse quickly. I'm just curious to know if others leak as well under high boost.

special tool

I used to run 35 psi sometimes through mine that was rebuilt.
With a lot of CFM.
It didn't leak.

How exactly are you testing it?

eniac

With a pressure testing rig I made from my old IC pipe. I simply connect to my TB and air compressor then slowly adjust the pressure up to the level I want. This also works good for checking the accuracy of the 4 boost sensors I have .

special tool

Yes, I know how to pressure test a 951.

Did you take the crank case out of the loop?
The air that squeeks out of the oilcap and the dipstick sounds like the TB.

eniac

Yeah I can feel it around the shaft seals right around 23psi, some bubbly soap confirmed this. If it was normal I would have no concern but since yours didn't leak at 35psi, I will further investigate this. It is minor but if it something that shouldn't be then I wanna take care of it.

special tool

Interesting.
Are you sure you didn't rip o-rings upon installation?

Also - we must consider the output of your compressor - are you using something like this........

eniac

LOL, no just a basic 55gal. shop compressor. I have an air adjuster with a guage attached to my IC pipe so I'm not blasting 90psi into it. I start with the air off then slowly increase it to the amount I want while carefully watching the guage.

At first I thought I had made an error on assembly so I rebuilt it again with a new kit, I then tried a different TB from a '86 951 which leaked around 23 psi as well, a third used TB innitially leaked at 12psi then after rebuilding was around 20psi when air started to escape around the shaft seals. That paticular TB was in very poor shape to begin with. Under that it doesn't leak at all, well nothing noticable, so I don't think there is really anything wrong with it by normal standards.

Thanks

blown 944

I never checked the TB for any leakage but now that you have this up it is good food for thought while it's down.

Honestly though it is most likely very marginal and it is pretty easy to just turn it up a little more

But thanks for the idea anyway

eniac

It's certainly not enough to affect boost