brake issues after cam install

Tech discussions on the L77 6.0L V8.
elmer91
Posts: 37
Joined: Sat Aug 15, 2015 6:00 pm

brake issues after cam install

Post by elmer91 »

I just installed the stage 1 LS3 cam from Texas Speed, and went to pull it out of the garage, and had very little brakes. Checked the vacuum, 8 in/merc (or whatever the standard is) at idle. compared it to my dad's truck with the 5.3, and it had 20. I wouldnt think that is a big enough cam to cause a drop in vacuum, and i check what lines i could and none was loose. I am going to check for leaks again, but figured i would ask if others had problems. The only think I thought it could be is the new valley cover had a stem coming off of it by the throttle body, and there was no where to hook it to, so i left the cap on it. could that be my leak, and if so, where does it go?
2012 9C1 Caprice PPV, totaled
2012 9C1 Caprice PPV, soon to have TSP LS3 stage 1 cam, DOD delete, solo axle back, rotofab CAI, tuned
2005 Chevrolet Silverado 1500 Z71
1989 BMW 325i
jackleg
Posts: 99
Joined: Wed May 04, 2016 9:25 pm
Location: SW MI

Re: brake issues after cam install

Post by jackleg »

I had to replace the large vacation hose that connects the brake booster to the rear of the intake. The end that connects to the intake was deteriorated and was about to split open.
2011 9C1 6.0
RCR "Little Lunati" 219/223 .625/.625 112+0
Kooks headers, hi flow cats, Dynomax Super Turbos
Flex fuel tune
elmer91
Posts: 37
Joined: Sat Aug 15, 2015 6:00 pm

Re: brake issues after cam install

Post by elmer91 »

Thanks, I'll look into that. Since that connection isn't the easiest to get to I didn't have time to check it today.
2012 9C1 Caprice PPV, totaled
2012 9C1 Caprice PPV, soon to have TSP LS3 stage 1 cam, DOD delete, solo axle back, rotofab CAI, tuned
2005 Chevrolet Silverado 1500 Z71
1989 BMW 325i
elmer91
Posts: 37
Joined: Sat Aug 15, 2015 6:00 pm

Re: brake issues after cam install

Post by elmer91 »

Sprayed brake cleaner over all of the hoses and connections and found no leaks. Also found something online to cap off the rear of the driver side valve cover and use the other end of that connection (passenger side of the intake up by the throttle body) and connect it to the port on the new valley cover. That didn't work either.
2012 9C1 Caprice PPV, totaled
2012 9C1 Caprice PPV, soon to have TSP LS3 stage 1 cam, DOD delete, solo axle back, rotofab CAI, tuned
2005 Chevrolet Silverado 1500 Z71
1989 BMW 325i
User avatar
Raunchtastic
Posts: 113
Joined: Fri Sep 25, 2015 10:53 pm

Re: brake issues after cam install

Post by Raunchtastic »

Is the stage 1 that you are referring to the 225/230? I just did that can and the brakes aren't as strong as they were, but it doesn't push through from a stop. Is the car idling high at all? If not, it probably isn't a vacuum leak, especially if you have no CEL. I'm at a loss. Have you had the vehicle tuned for the cam?
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2012 Chevrolet Caprice "The Daily"
1992 Chevrolet Camaro RS 25th anniversary "The Wannabe Racecar"
elmer91
Posts: 37
Joined: Sat Aug 15, 2015 6:00 pm

Re: brake issues after cam install

Post by elmer91 »

yeah it is the 225/230 cam. i havent had it tuned yet, that is wednesday. This is the first cam change ive ever done, and wasnt expecting the brakes to be this bad. ilde is about 800 rpm. most people are saying i should get better brakes once its tuned. the CEL codes I have are :
B2AAA -Random body code that I cant find any info on
P3401- Cylinder 1 deactivation/Intake valve control circuit/open
P3425- Cylinder 4 deactivation/Intake valve control circuit/open
P3441- Cylinder 6 deactivation/Intake valve control circuit/open
P3449- Cylinder 7 deactivation/Intake valve control circuit/open

The 4 engine codes are from the DOD not being there anymore. I also had one for random cylinder misfire, but cleared codes and it didnt come back. probably from the DOD delete.
2012 9C1 Caprice PPV, totaled
2012 9C1 Caprice PPV, soon to have TSP LS3 stage 1 cam, DOD delete, solo axle back, rotofab CAI, tuned
2005 Chevrolet Silverado 1500 Z71
1989 BMW 325i
User avatar
Raunchtastic
Posts: 113
Joined: Fri Sep 25, 2015 10:53 pm

Re: brake issues after cam install

Post by Raunchtastic »

I was able to drop my idle down to 725rpms and it's pretty stable. If you are tuning it yourself, you can just pull some timing from idle speed and it will stop that feeling of wanting to push through the brakes. I went with this cam as it was recommended as the biggest cam I can comfortably run without changing the stall. Because of this, I figured it would still have some push. Hopefully the tune will correct the issue.
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2012 Chevrolet Caprice "The Daily"
1992 Chevrolet Camaro RS 25th anniversary "The Wannabe Racecar"
elmer91
Posts: 37
Joined: Sat Aug 15, 2015 6:00 pm

Re: brake issues after cam install

Post by elmer91 »

It's not pushing through the brakes, once it stops it stays stopped. I just have less brakes now, taking longer to stop.
2012 9C1 Caprice PPV, totaled
2012 9C1 Caprice PPV, soon to have TSP LS3 stage 1 cam, DOD delete, solo axle back, rotofab CAI, tuned
2005 Chevrolet Silverado 1500 Z71
1989 BMW 325i
User avatar
Raunchtastic
Posts: 113
Joined: Fri Sep 25, 2015 10:53 pm

Re: brake issues after cam install

Post by Raunchtastic »

That's odd. My brakes were still able to stop the car in the same or similar brake feel, but at a light I do notice that the pedal needs to be held a bit firmer. I also noticed that when brake-torquing it will push through the brakes rather than spin the rears, which I thought to be odd. I just figured I'm making less power under 1500rpms than before, as I haven't had it tuned professionally yet. My only thought is that since there is less vacuum at idle/cruise the brakes don't feel as effective.
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2012 Chevrolet Caprice "The Daily"
1992 Chevrolet Camaro RS 25th anniversary "The Wannabe Racecar"
Ridgeppv
Posts: 74
Joined: Wed Oct 20, 2021 4:59 pm
Location: Indianapolis

Re: brake issues after cam install

Post by Ridgeppv »

I dont think the OP is on here anymore, but was anyone ever run into this and found the fix? will replace the vacuum hose on the back of my intake to see if that works.
2014 6.0L BTR Stage 2 Cam, DOD Delete, 3.45 diff, long tube headers, VCM OTR Intake
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