Braking & Idle Questios - Hydroboost
Braking & Idle Questios - Hydroboost I am in the midst of tuning the 5.3 LMG & 6l80 out of a 2012 Tahoe with a 76m turbo. During my test drives I have noticed some problems with my brakes. This truck has sat for ~2yrs, but before that it had a SBC 400 and the brakes worked fine. This has disc brakes front, drum brakes rear. The truck weighs 5500 lbs and is a 51/49% weight distribution front to rear. The truck has the stock powersteering pump, the power steering gear box and hydroboost system are from a 79 chevy truck.
Initially, I noticed that when coming to a stop, the truck would bog down and die(TCC lockup switch is installed correcty) This was when the idle was set to 600rpm I have since raised it to 850and this has eliminated the problem. Any thoughts if I should lower this any?
Now My brakes are doing okay(not great) at the start, but after about 15 minutes of constant 0 to 35-40 then back to 0 in a neighborhood (17 stop signs in a 3.4 mile loop) the brakes faded and I actually wasn't able to stop until I was all the way through one of the stop signs... When I got back to my house, I used an infrared thermometer and the front rotors read ~400 and the rear drums read 125. The left/right variance is 15 degrees front and rear. The fluid is DOT 3.
I also noticed that after 10-15 minutes into my test drive, when the brakes are starting to fade and i have the pedal all the way to the floor, When I go to take off from a stop the truck sputters a little. If I coast to a stop using lighter brakes, it doesnt sputter on take off. I am wondering if this has to do with the hydroboost putting a load on the engine after hard stops.
Any suggestions are greatly appreciated.
Initially, I noticed that when coming to a stop, the truck would bog down and die(TCC lockup switch is installed correcty) This was when the idle was set to 600rpm I have since raised it to 850and this has eliminated the problem. Any thoughts if I should lower this any?
Now My brakes are doing okay(not great) at the start, but after about 15 minutes of constant 0 to 35-40 then back to 0 in a neighborhood (17 stop signs in a 3.4 mile loop) the brakes faded and I actually wasn't able to stop until I was all the way through one of the stop signs... When I got back to my house, I used an infrared thermometer and the front rotors read ~400 and the rear drums read 125. The left/right variance is 15 degrees front and rear. The fluid is DOT 3.
I also noticed that after 10-15 minutes into my test drive, when the brakes are starting to fade and i have the pedal all the way to the floor, When I go to take off from a stop the truck sputters a little. If I coast to a stop using lighter brakes, it doesnt sputter on take off. I am wondering if this has to do with the hydroboost putting a load on the engine after hard stops.
Any suggestions are greatly appreciated.
