Another Brake Problem thread
#1
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Well just got through doing my abs delete and car has a few problems. I have stock calipers, <1000 miles on HPS pads, turned powerslot rotors, SS lines, SJM !abs.
I let the MC go dry so I have bench bleed it. I have bleed the entire system with the motive power bleeder and have also manually bleed them with my wifes helps.
1. Still has a soft pedal.
I don't see anymore air coming out and I did hit the calipers with a mallet to dislodge any air trapped while manual bleeding.
2. Front brakes grind and pulse when stopping. Sounds like whenever the slots go through the pads is when I am getting the pulsing and grinding. I didn't feel the pedal pulsing just a pulse grinding sound from the front brakes. This is on any moderate to heavy breaking.
3. I noticed that the pass rear caliper would move (flex) alot when my wife was pressing the pedal down. Didn't notice any of the other calipers moving near this much. It wasn't the caliper just sliding on the pins it was like something was broken or loose. I did check and all bolts are torqued to specs on bracket and guide pin bolts.
So I don't really know where to start. Don't know what I did wrong or if I have bad parts. Do I have bad calipers, MC? Do I need new pads to go with the turned rotors, new rotors and pads? Any suggestions welcomed.
I let the MC go dry so I have bench bleed it. I have bleed the entire system with the motive power bleeder and have also manually bleed them with my wifes helps.
1. Still has a soft pedal.
I don't see anymore air coming out and I did hit the calipers with a mallet to dislodge any air trapped while manual bleeding.
2. Front brakes grind and pulse when stopping. Sounds like whenever the slots go through the pads is when I am getting the pulsing and grinding. I didn't feel the pedal pulsing just a pulse grinding sound from the front brakes. This is on any moderate to heavy breaking.
3. I noticed that the pass rear caliper would move (flex) alot when my wife was pressing the pedal down. Didn't notice any of the other calipers moving near this much. It wasn't the caliper just sliding on the pins it was like something was broken or loose. I did check and all bolts are torqued to specs on bracket and guide pin bolts.
So I don't really know where to start. Don't know what I did wrong or if I have bad parts. Do I have bad calipers, MC? Do I need new pads to go with the turned rotors, new rotors and pads? Any suggestions welcomed.
#2
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I let my MC go dry once. It just wasn't the same no matter what I did.. fluid looked clean/solid with no bubbles. It wasn't the same until I brought it to the shop... I'm not sure what they use to redo the fluid but I had a firm pedal after that. I know.. not the answer you want to hear.. but it wasn't too expensive and fixed my problem
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#3
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I let my MC go dry once. It just wasn't the same no matter what I did.. fluid looked clean/solid with no bubbles. It wasn't the same until I brought it to the shop... I'm not sure what they use to redo the fluid but I had a firm pedal after that. I know.. not the answer you want to hear.. but it wasn't too expensive and fixed my problem ![Happy](https://ls1tech.com/forums/images/smilies/LS1Tech/gr_stretch.gif)
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#4
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I know you deleted the ABS, but if you still have the ABS module in the car it needs to be cycled with a Tech 2 to remove all the air from the lines. Also it sounds like part of the soft pedal is from the movement in the passenger rear caliper. Perhaps the caliper mounting bracket is cracked, since you checked everything else.
#5
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I know you deleted the ABS, but if you still have the ABS module in the car it needs to be cycled with a Tech 2 to remove all the air from the lines. Also it sounds like part of the soft pedal is from the movement in the passenger rear caliper. Perhaps the caliper mounting bracket is cracked, since you checked everything else.
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#9
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Just had my wife press on the brakes so I could check that caliper and it is still flexing. I guess it has to be the guide pins. If they are not letting the back side of the caliper move away from the rotor then I guess the whole thing will flex and twist like it is doing? Can air trapped in the caliper cause this as well?
#10
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Maybe a dumb question, but it's happened ... is the MC port closest to the nose of the car feeding the rear brakes and the port closest to the firewall feeding the front brakes?
How did you bench bleed the MC? On the car or in a vise?
If you left it on the car, the angle of the mount is such that a small air bubble could be trapped in the very end of the cylinder. Also, plunging the brake pedal won't give you 100% stroke at the MC.
Best way to bench bleed is in a vice with the ***-end tilted up and completely plunge the piston. Shouldn't take but a few strokes.
Caliper movement at the end is not that big of a deal. You might have a slightly spread caliper and it's racking the pads back and forth. As long as it's moving along the guide pins and not mechanically moving anywhere else.
Spread is not good, but not the end of the world. The pads will wear strange and you won;t get the mileage out of them you might otherwise. But it's certainly not a deal breaker.
I wuld look at getting a replacement caliper and swap it out next pad change.
How did you bench bleed the MC? On the car or in a vise?
If you left it on the car, the angle of the mount is such that a small air bubble could be trapped in the very end of the cylinder. Also, plunging the brake pedal won't give you 100% stroke at the MC.
Best way to bench bleed is in a vice with the ***-end tilted up and completely plunge the piston. Shouldn't take but a few strokes.
Caliper movement at the end is not that big of a deal. You might have a slightly spread caliper and it's racking the pads back and forth. As long as it's moving along the guide pins and not mechanically moving anywhere else.
Spread is not good, but not the end of the world. The pads will wear strange and you won;t get the mileage out of them you might otherwise. But it's certainly not a deal breaker.
I wuld look at getting a replacement caliper and swap it out next pad change.
#11
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
Maybe a dumb question, but it's happened ... is the MC port closest to the nose of the car feeding the rear brakes and the port closest to the firewall feeding the front brakes?
How did you bench bleed the MC? On the car or in a vise?
If you left it on the car, the angle of the mount is such that a small air bubble could be trapped in the very end of the cylinder. Also, plunging the brake pedal won't give you 100% stroke at the MC.
Best way to bench bleed is in a vice with the ***-end tilted up and completely plunge the piston. Shouldn't take but a few strokes.
Caliper movement at the end is not that big of a deal. You might have a slightly spread caliper and it's racking the pads back and forth. As long as it's moving along the guide pins and not mechanically moving anywhere else.
Spread is not good, but not the end of the world. The pads will wear strange and you won;t get the mileage out of them you might otherwise. But it's certainly not a deal breaker.
I wuld look at getting a replacement caliper and swap it out next pad change.
How did you bench bleed the MC? On the car or in a vise?
If you left it on the car, the angle of the mount is such that a small air bubble could be trapped in the very end of the cylinder. Also, plunging the brake pedal won't give you 100% stroke at the MC.
Best way to bench bleed is in a vice with the ***-end tilted up and completely plunge the piston. Shouldn't take but a few strokes.
Caliper movement at the end is not that big of a deal. You might have a slightly spread caliper and it's racking the pads back and forth. As long as it's moving along the guide pins and not mechanically moving anywhere else.
Spread is not good, but not the end of the world. The pads will wear strange and you won;t get the mileage out of them you might otherwise. But it's certainly not a deal breaker.
I wuld look at getting a replacement caliper and swap it out next pad change.
I bench bleed the MC in a vise. Tried to have it as level as possible and ran lines back into it while I bleed it. all air was out of it when I went to reinstall.
Oh and yes the lines are feeding the correct brakes.