Terrible braking after Cam/Heads
07-07-2010, 09:10 AM
#1
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Join Date: Jul 2010
Posts: 5
Terrible braking after Cam/Heads
Right after I had a cam and heads put in my brakes barely do their job. It's hard to keep the car at stop lights without putting it in neutral. I had the shop do new rotors/pads/calipers as they were old and that did not fix the problem. They called me and said there was only 5 PSI in the system for braking so they installed an air accumulator which helped when the car is going over 30 MPH but did not help at red lights and slower speeds. Whats the next step?
It's a 1994 Camaro Z28 with long tubes, heads and cam.
It's a 1994 Camaro Z28 with long tubes, heads and cam.
Last edited by whitecamaroz29; 07-07-2010 at 09:13 AM.
07-07-2010, 09:18 AM
#2
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Join Date: Aug 2006
Posts: 922
Right after I had a cam and heads put in my brakes barely do their job. It's hard to keep the car at stop lights without putting it in neutral. I had the shop do new rotors/pads/calipers as they were old and that did not fix the problem. They called me and said there was only 5 PSI in the system for braking so they installed an air accumulator which helped when the car is going over 30 MPH but did not help at red lights and slower speeds. Whats the next step?
It's a 1994 Camaro Z28 with long tubes, heads and cam.
It's a 1994 Camaro Z28 with long tubes, heads and cam.
07-07-2010, 09:29 AM
#6
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Join Date: Aug 2006
Posts: 922
I have never heard of a cam and heads causing a positive pressure in the manifold. I don't think it's possible.
Check the line to your power brake booster. Replace the line if necessary. It could be the booster itself. If the power brake booster diaphragm is defective or damaged it won't work causing the brakes to be difficult to operate.
Check the line to your power brake booster. Replace the line if necessary. It could be the booster itself. If the power brake booster diaphragm is defective or damaged it won't work causing the brakes to be difficult to operate.
07-07-2010, 09:52 AM
#9
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How big is the cam? Who tuned it? What is the MAP at idle? If you don't have a scanner to pull the MAP readings, what it the vacuum at idle?
A stock cam will pull about 20"Hg (33kPa MAP) at idle. A large cam might only pull 10"Hg (66kPa MAP) at idle. A really big cam will pull less vacuum than that. Is your SES light on due to high MAP (low vacuum)?
Its very unusual to see vacuum referenced in "psi"..... its usually expressed in inches of mercury ("Hg) or kiloPascals (kPa).
A stock cam will pull about 20"Hg (33kPa MAP) at idle. A large cam might only pull 10"Hg (66kPa MAP) at idle. A really big cam will pull less vacuum than that. Is your SES light on due to high MAP (low vacuum)?
Its very unusual to see vacuum referenced in "psi"..... its usually expressed in inches of mercury ("Hg) or kiloPascals (kPa).
07-07-2010, 10:46 AM
#10
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Join Date: Jul 2010
Posts: 5
1994 LT1 Z28
Y pipe 3\"
lingenfelter supertube CAI
flowmaster 80 series exhaust
highflow cat
hooker long tube headers
AI 180cc Street/Strip LT1 Cylinder Head & Cam Package
Hand Ported Intake/Exhaust Runners
Chambers CNC Contoured & Un-shrouded w/Newen
Newen CNC F1 Quality Competition Valve Job
Machine Guides For .530 ID Valve Seals
Mill Deck to Ensure Surface Finish, Flatness, and Desired Chamber Volume
(51cc -55cc)
Pressure & Hardness Tested to Ensure the Casting\'s Integrity & Ability to
Hold Cylinder Pressure
Competition Plus 21-4N Stainless Super-Flo Valves 2.00 Int/1.57Exh
w/Hi-Performance Metal Clad Viton
Valve Seals
CompCams 26918 Beehive Spring w/ Comp 10 Deg Hardened & Machined 4130
Steel Components
Ai Custom Hydraulic Roller Camshaft (Billet Steel Core-Not Cast Core,
CC306)
30# Ford SVO Fuel Injectors
Comp Pro Mag 1.6 RR
No Air Pump
No EGR
MSD wires
NGK Iradium Plugs
Mezier Heavy Duty Water Pump
Stock MAF
Stock Transmission
Madz28 did the tune.
I'll have to wait to get the other info. The mechanic suggested an electric pump is this worth it?
Y pipe 3\"
lingenfelter supertube CAI
flowmaster 80 series exhaust
highflow cat
hooker long tube headers
AI 180cc Street/Strip LT1 Cylinder Head & Cam Package
Hand Ported Intake/Exhaust Runners
Chambers CNC Contoured & Un-shrouded w/Newen
Newen CNC F1 Quality Competition Valve Job
Machine Guides For .530 ID Valve Seals
Mill Deck to Ensure Surface Finish, Flatness, and Desired Chamber Volume
(51cc -55cc)
Pressure & Hardness Tested to Ensure the Casting\'s Integrity & Ability to
Hold Cylinder Pressure
Competition Plus 21-4N Stainless Super-Flo Valves 2.00 Int/1.57Exh
w/Hi-Performance Metal Clad Viton
Valve Seals
CompCams 26918 Beehive Spring w/ Comp 10 Deg Hardened & Machined 4130
Steel Components
Ai Custom Hydraulic Roller Camshaft (Billet Steel Core-Not Cast Core,
CC306)
30# Ford SVO Fuel Injectors
Comp Pro Mag 1.6 RR
No Air Pump
No EGR
MSD wires
NGK Iradium Plugs
Mezier Heavy Duty Water Pump
Stock MAF
Stock Transmission
Madz28 did the tune.
I'll have to wait to get the other info. The mechanic suggested an electric pump is this worth it?
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