Brake issue after motor build
Sep 9, 2012, 03:03 PM
#1
Brake issue after motor build
I searched and read countless threads about brake boosters going bad and having the brakes stiff and pedal not moving far...
I am having this same issue after building my motor. Before pulling it everything worked just fine... Built the motor, top to bottom. And now the brake pedal only moves 1/2" and then it is like kicking a brick wall...
The vacuum line from the intake manifold to the brake booster is fine. I bled the brakes. Car still stops but the pedal play is so short...
What would cause this after the build?
Or what would cause the booster to fail during the down time of the build 
Any and all insight is greatly appreciated
I am having this same issue after building my motor. Before pulling it everything worked just fine... Built the motor, top to bottom. And now the brake pedal only moves 1/2" and then it is like kicking a brick wall...
The vacuum line from the intake manifold to the brake booster is fine. I bled the brakes. Car still stops but the pedal play is so short...
What would cause this after the build?
Or what would cause the booster to fail during the down time of the build Any and all insight is greatly appreciated
Sep 9, 2012, 04:51 PM
#2
Sounds like a boost assist issue. When you did the build did you take off the booster hose with check valve? Make sure this is all okie dokie.... also you can try to put a vac gauge on the booster hose to see what it is seeing.
Of course we are assuming you did absolutely nothing to the brakes, as you kind of mentioned.
Of course we are assuming you did absolutely nothing to the brakes, as you kind of mentioned.
Sep 9, 2012, 05:47 PM
#3
Sounds like a boost assist issue. When you did the build did you take off the booster hose with check valve? Make sure this is all okie dokie.... also you can try to put a vac gauge on the booster hose to see what it is seeing.
Of course we are assuming you did absolutely nothing to the brakes, as you kind of mentioned.
Of course we are assuming you did absolutely nothing to the brakes, as you kind of mentioned.
Sep 10, 2012, 07:10 AM
#7
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You need to make sure the check valve inside of your brake booster line is in the correct orientation, or you didn't put the line on backwards. I would disconnect the booster line in its entirety and make sure you can "suck" in air through the hose from the intake manifold connection size. Down here in the south we have mudbugs that love to make nests in little disconnected lines like that and royally screw things up while your car is down for a bit.
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Sep 10, 2012, 07:43 AM
#8
You need to make sure the check valve inside of your brake booster line is in the correct orientation, or you didn't put the line on backwards. I would disconnect the booster line in its entirety and make sure you can "suck" in air through the hose from the intake manifold connection size. Down here in the south we have mudbugs that love to make nests in little disconnected lines like that and royally screw things up while your car is down for a bit.
However The line was never removed from the booster. The arrow is still pointing and reads " <-----ENGINE" going in the right direction.
I'm not even certain where the check valve is
I'll hope somethigns stuck in the line or its in the correct orrientation. thanks a bunch
Sep 10, 2012, 05:00 PM
#9
The check valve is between the booster and the manifold..... I'd use another hose and bypass the valve entirely just to see if that fixes it. Other than that, sounds stupid, but bleed (or flush) your brake fluid
Have you driven the car yet? Or just idle? What is your vac level difference at idle (before and after cams)?
Its normal for the pedal to be hard when the car is off.
Have you driven the car yet? Or just idle? What is your vac level difference at idle (before and after cams)?
Its normal for the pedal to be hard when the car is off.
Last edited by GTijoejoe; Sep 10, 2012 at 05:05 PM.
Sep 11, 2012, 06:39 AM
#10
The check valve is between the booster and the manifold..... I'd use another hose and bypass the valve entirely just to see if that fixes it. Other than that, sounds stupid, but bleed (or flush) your brake fluid
Have you driven the car yet? Or just idle? What is your vac level difference at idle (before and after cams)?
Its normal for the pedal to be hard when the car is off.
Have you driven the car yet? Or just idle? What is your vac level difference at idle (before and after cams)?
Its normal for the pedal to be hard when the car is off.
I'll try to have the fluid all flushed, I bled the brakes like each corner 4+ times, and capped off the fluid twice.. hoped taht cycled it... however whats another shot..
I have driven the car like 10miles total now, car still stops just as mentioned i get a 1/2" of travel in the pedal
I dont remember what my vacuum was before the build.. i think like 20/22? I'll have to check today what the new vacuum is when tis started. Thanks a bunch so far Joe, you're going to h2o this year ya?
Sep 12, 2012, 07:09 AM
#13
In regards to h2o, they suck hahahah
Sep 12, 2012, 08:39 AM
#15
yup, if you are getting this much vac than you have extremely low boost assist, which would make it seem the booster is not working at all but actually hurting you as you still have to overcome all the spring forces etc. inside the booster.
This is why in gear, engine braking your vac increases and your brakes seem normal.
You need to be sure you don't have any vac leaks in your intake manifold.
This is why in gear, engine braking your vac increases and your brakes seem normal.
You need to be sure you don't have any vac leaks in your intake manifold.