Help! No vacum for brakes!
Thread Starter
Racer
Joined: Jan 2003
Posts: 270
Likes: 0
From: Erie pa
Help! No vacum for brakes!
I have no vacum on my 96 at the power brake line. I pull vacum at the other two fittings near it on the drivers side of the intake. My valve is working OK, and when I pulled the fitting out and secured a line into the intake using the grommet, it still pulled no vacum. I can reach my finger in the opening and I don't feel any obstructions. I just got my motor in and everything worked fine before I took it apart. I have CC 305 cam in it, but that shouldn't cause any trouble, since i pull vacum at the other fittings. Please let me know of any suggestions. Thanks. Eric
:crazy: :confused:
:crazy: :confused:
Melting Slicks
Joined: Sep 2000
Posts: 3,150
Likes: 1
From: Carlsbad, CA CA
Re: Help! No vacum for brakes! (spinedoc)
It sounds like it is your brake booster. The plastic booster is prone to cracks from heat, especially if you have headers.
If it is the booster, save yourself the trouble and replace it with a ZR-1 unit, they are steel and will not crack. Otherwise, You will be replacing boosters on a regular basis.
If it is the booster, save yourself the trouble and replace it with a ZR-1 unit, they are steel and will not crack. Otherwise, You will be replacing boosters on a regular basis.
Thread Starter
Racer
Joined: Jan 2003
Posts: 270
Likes: 0
From: Erie pa
Re: Help! No vacum for brakes! (zelement)
Do you mean the booster by the master cylinder? I can't even get that far. I do not have any vacum at the intake manifold. I plugged my gauge right into the manifold and have nothing in that hole, but vacum in the ones next to it. Help.
Le Mans Master
Joined: Feb 2000
Posts: 9,715
Likes: 27
From: Kempner Texas
Re: Help! No vacum for brakes! (spinedoc)
Problem is you're on the C4 board and many of us aren't familiar with the intake setup you're running.
When you refer to plugging your gauge into the intake manifold and not getting any vacuum reading but there's vacuum at the one next to it, we - at least I'm at a loss.
Our brake booster vacuum hose screws into the back of the plenum.
Of course, I'd like to help if I can, but I need to know more about your particular setup since it's not a TPI.
jAKE
When you refer to plugging your gauge into the intake manifold and not getting any vacuum reading but there's vacuum at the one next to it, we - at least I'm at a loss.
Our brake booster vacuum hose screws into the back of the plenum.
Of course, I'd like to help if I can, but I need to know more about your particular setup since it's not a TPI.
jAKE
Thread Starter
Racer
Joined: Jan 2003
Posts: 270
Likes: 0
From: Erie pa
Re: Help! No vacum for brakes! (JAKE)
It's a factory LT4 intake. The brake booster hose is plugged into the drivers side of the manifold about halfway. Near it are two other smaller vacum ports with lines, both of which have vacum. Nothing special. Thanks.
Melting Slicks
Joined: Aug 1999
Posts: 2,240
Likes: 42
From: Baltimore, MD USA
Re: Help! No vacum for brakes! (spinedoc)
Are you doing a LT1 to LT4 intake manifold upgrade?
Look at this picture. The vacuum port for the brake booster is using the top hole.
http://www.97ta.com/lt4/lt470.jpg
Look at this picture. The vacuum port for the brake booster is using the top hole.
http://www.97ta.com/lt4/lt470.jpg
Thread Starter
Racer
Joined: Jan 2003
Posts: 270
Likes: 0
From: Erie pa
Re: Help! No vacum for brakes! (Hooked on Vettes)
Jake- I see what you mean, I need to update the sig.
Hooked- Now we are getting somewhere! My brake booster line is hooked up to the port down low, the one with the rubber grommet. My timing is hooked to the larger port above it, and another line comes of the smaller one heading to the front of the car. Maybe I have hooked them up wrong! Does anyone have a pic with all lines hooked up? The motor is an original LT4 in a CE car. Thanks! :cheers:
[Modified by spinedoc, 9:47 PM 5/30/2004]
Hooked- Now we are getting somewhere! My brake booster line is hooked up to the port down low, the one with the rubber grommet. My timing is hooked to the larger port above it, and another line comes of the smaller one heading to the front of the car. Maybe I have hooked them up wrong! Does anyone have a pic with all lines hooked up? The motor is an original LT4 in a CE car. Thanks! :cheers:
[Modified by spinedoc, 9:47 PM 5/30/2004]
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