I'm in the middle of my 3800 swap and I figured I'd fix my vacuum leak while I was at it. However, I have no clue where the brake booster vacuum line goes. I have the 3" thick manual, but it stops at the firewall. Can someone please tell me its path through the vehicle to the engine?

Thanks,

Mike

Hi Mike,

I am assuming all years are alike but that is just an assumption.

On my 88 the line goes through the forward bulkhead (firewall for front engine cars) just above the pivot for the gas pedal and then routes under the stereo and along the left side of the "hump" (that runs from front to rear of the passenger compartment) underneath the skeleton. At the rear of the "hump" near the back of the center armrest it does a 90 degree turn towards the passenger side of the hump and goes through the firewall. Looking from the back of the car forward you should see it sticking out close to the center of the engine bay on the firewall. Just guessing but maybe 6" or so below the rear window.

Charlie

[This message has been edited by cptsnoopy (edited 12-16-2010).]

I would first look to prove (or actually disprove) the line itself has a leak in it. Unless somehow the line got damaged, any leak would most likely be in the brake booster itself.

Yeah, I would guess either the booster or one of the hose connections is leaking. There's a rubber hose that connects the booster to the hard line... which runs under the console, as mentioned above. It wouldn't hurt to check that hose. Getting at the hard line will require removing the entire console assembly.

quote Originally posted by Blacktree: Yeah, I would guess either the booster or one of the hose connections is leaking. There's a rubber hose that connects the booster to the hard line... which runs under the console, as mentioned above. It wouldn't hurt to check that hose. Getting at the hard line will require removing the entire console assembly.

Ok. So a hard line goes from the front bulkhead to the firewall in the rear? I'll inspect it for rust, but I expect it to be immaculate. Chances are it was a vacuum leak behind the firewall having to do with the engine. The 2.8L in there ran like crap. Imagine an idle that wanders between 1000 rpm and 3000 rpm depending on the day of the week.