hard pedal - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

mikepage0007 · 04-02-2014, 06:53 PM

lookig for some input...installed a new 427lsx and 4l80 also has a decent lift cam , which i am sure is not helping... , finally and getting back on the road...seems that hitting the brakes and staying on the brake pedal, brakes feel good...now if you hit the brakes and let off and immediately reapply the brakes, they go rock hard as if the engine is off and there is no power assist to stop the car, we have not found any vacuum leaks and am looking at any idea,s that anyone may have...this 427 is whipple sc, along with 200 shot nos injection kit.car is not completely on road yet as we just had to pull the tranny back out as we had a rear oring leak on the rear seal housing...but soon it will be back on road and looking for all idea,s on what may be causing the brakes to drop off, thanks , guys

Dimitrim · 04-03-2014, 12:00 PM

With a vacuum gauge measure the vacuum at idle and off idle. What is it? Also watch the gauge when brakes are applied.

mikepage0007 · 04-03-2014, 07:19 PM

my mechanic has checked vacuum and is in single digits if i remember correctly..we believe that there may be a issue with the nos solenoid valves as they are direct into the intake manifold and may be causing vacuum loss ..we will look more into that next week..i have been considering the electric pump, just hoping that maybe there is something else causing the issues...have not heard of to many having this issue after installing a cam..

Dimitrim · 04-03-2014, 08:22 PM

Was the Cam installed correctly? Talk to the cam manufactures see what they say. Blueprint the cam for irregularities. Having such low vacuum is very unhealthy for the bottom end.

NC-V · 04-03-2014, 08:42 PM

Single digit vacuum numbers are definitely why your power brakes suck. For good, repeatable stops one after another you would want to see at least 15" at idle/ cruise. Sounds like the engine just isn't producing enough vacuum to replenish the booster after 1 brake pump. Fix your vacuum issue and your brakes should work again. (if it is just a huge cam and you are sticking with it, than you may need an electric vac pump.)

mikepage0007 · 04-26-2014, 07:57 AM

anyone have any recomendations on a quiet electric pump?

04-02-2014, 06:53 PM	#1
mikepage0007 Drives: 2010 camaro Join Date: Aug 2009 Location: port st lucie ,florida Posts: 4,273	hard pedal lookig for some input...installed a new 427lsx and 4l80 also has a decent lift cam , which i am sure is not helping... , finally and getting back on the road...seems that hitting the brakes and staying on the brake pedal, brakes feel good...now if you hit the brakes and let off and immediately reapply the brakes, they go rock hard as if the engine is off and there is no power assist to stop the car, we have not found any vacuum leaks and am looking at any idea,s that anyone may have...this 427 is whipple sc, along with 200 shot nos injection kit.car is not completely on road yet as we just had to pull the tranny back out as we had a rear oring leak on the rear seal housing...but soon it will be back on road and looking for all idea,s on what may be causing the brakes to drop off, thanks , guys __________________ Last edited by mikepage0007; 04-02-2014 at 07:05 PM.

04-03-2014, 07:19 PM	#3
mikepage0007 Drives: 2010 camaro Join Date: Aug 2009 Location: port st lucie ,florida Posts: 4,273	my mechanic has checked vacuum and is in single digits if i remember correctly..we believe that there may be a issue with the nos solenoid valves as they are direct into the intake manifold and may be causing vacuum loss ..we will look more into that next week..i have been considering the electric pump, just hoping that maybe there is something else causing the issues...have not heard of to many having this issue after installing a cam.. __________________

04-03-2014, 08:42 PM	#5
NC-V Drives: cts-v Join Date: Dec 2011 Location: Mooresville, NC Posts: 506	Single digit vacuum numbers are definitely why your power brakes suck. For good, repeatable stops one after another you would want to see at least 15" at idle/ cruise. Sounds like the engine just isn't producing enough vacuum to replenish the booster after 1 brake pump. Fix your vacuum issue and your brakes should work again. (if it is just a huge cam and you are sticking with it, than you may need an electric vac pump.) __________________ S.L. Customs www.slcustomsonline.com www.facebook.com/S.L.CustomsLLC

04-26-2014, 07:57 AM	#6
mikepage0007 Drives: 2010 camaro Join Date: Aug 2009 Location: port st lucie ,florida Posts: 4,273	anyone have any recomendations on a quiet electric pump? __________________

04-03-2014, 12:00 PM	#2
Dimitrim Dimitri Drives: 68 GTO 455 Ram Air; 2014 Camaro ZL1 Join Date: Jan 2014 Location: Novato, California Posts: 602 View My Garage	With a vacuum gauge measure the vacuum at idle and off idle. What is it? Also watch the gauge when brakes are applied.

04-03-2014, 08:22 PM	#4
Dimitrim Dimitri Drives: 68 GTO 455 Ram Air; 2014 Camaro ZL1 Join Date: Jan 2014 Location: Novato, California Posts: 602 View My Garage	Was the Cam installed correctly? Talk to the cam manufactures see what they say. Blueprint the cam for irregularities. Having such low vacuum is very unhealthy for the bottom end.