where is the brake booster?

[Ryan...]

Planning on using up the rest of my seafoam tomorrow, can anyone point out which is the brake booster?

[E30SPDFRK]

Big black circle on your firewall, drivers side.

Be careful out there man

[Ryan...]

Big black circle on your firewall, drivers side.

Be careful out there man

How the heck do you seafoam an M42? I thought it was supposed to be a line?

[Simon S]

The brake booster vac hose connects to the lower intake manifold.

That connection point is open to only one of the intake runners (the one closest to the firewall), just before induction to cylinder head.

Point is – I think ‘seafoaming’ an m42 using the brake booster hose would only effectively clean one of the four compression chambers.

I’m planning to seafoam my m42 in the near future – and when I do – I’ll be attempting to use that small/thin vac hose from the fuel pressure regulator. It runs to the throttle body and would seem to be a better induction point as all cylinders/compression chambers would receive treatment.

In the following picture, one can see where the brake booster vac hose connects to the lower intake runner. While not visible in pic, there is a small orifice inside the right-most runner – just opposite of where the vac hose connects to it.



The fuel pressure regulator (in above pic) can be seen (not very well) at the left-most end of the fuel rail. Due to space constraints, it’s tricky to remove and install that small/thin vac line. Needle nose pliers allowed me the reach and grab to get that hose on.

Knowing about that hose should be the only trick really. Searching should turn up a number of seafoam procedure DIYs.

[Simon S]

Here's a better shot of that opening in the one (right-most) intake runner. You can just see it at about the 8:00 position.



And here's a shot of the fuel presure regulator hose:

[Ryan...]

wow thanks for all the info!!!!

I'll probably just put the rest in my gas tank for now and buy some to do this next time :)