New master cylinder, new power brake booster, rotors & pads, cleaned calipers and fresh fluid of course. The brakes work great and have firm pedal, if anything maybe too firm. No noise from rotors & pads but after 3-4 miles there's a very noticeable drag, as if from residual pressure maybe, and the car will slowly come to a rest on it's own without applying pedal. Once it reaches this point the car can sit at a stop light without applying brakes at all and just sit in place.

I'm hoping someone has had a very similar experience or has extensive knowledge of these somewhat complex braking systems GM crammed into this car. The only components under the hood that hasn't been replaced is the ABS module itself but there is no ABS or Traction Control lighting up on the cluster.Could it be when replacing the booster & master cylinder that the push rod length wasn't adjusted right, causing too much length and preventing the master cylinder from relaxing entirely keeping the pads pressed against the rotors?

I had a mechanic shop do this work and when I initially picked the car up it seemed great. But the same issue of drag was much worse and was heating up the right front so bad there was smoke coming from the wheel well. Had it towed back to the shop and had the car for 3-4 days and the issue is still there although I haven't seen the heating up like we did on the first trip home with it but. The mechanic admitted that although it was better, or seemed to be, there is still some issue but have thrown their hands up in trying to narrow down what's causing this and simply returned all the repair cost monies to me. So we have all new components at no cost but still no drivable car.

 

I know you mentioned they cleaned the calipers- were they inspected internally also? Anything odd with the condition of the pistons / bores?

Slide pins are lubed and not overly pitted / corroded?


You'd think if that were the case, they'd know it immediately. Once installed, spinning the wheels by hand (with the car off the ground of course), you'd be able to feel that something wasn't right up front if they were notably harder to turn than they should be. That cause wouldn't take time to manifest itself once the brakes were pumped back up.

 

I can't say if the calipers were internally inspected for sure but he's typically pretty thorough and did say the calipers were in good condition.

With regards to this. He did tell me that in trying to isolate the issue, when the car was up off the ground and he could feel the resistance when rotating the wheels (all 4 of them according to him). But at each wheel when he opened the bleeder screw, pressure released, he would close the bleeder again and the wheel would spin freely. He took it for several short drives and each time could feel the pressure building again and he would repeat this process. He did this until he thought he had it as good as he could get it and finally was ready to throw in the towel. I suspect some of the problem may be that he's used to working on newer compact cars like Honda's etc because he he was honest in saying that this system was just more complex than he was used too. For whatever reason he seems to think there's and issue with the ABS module because he had to detach the MC from it when he replaced the MC. I'm having a hard time understanding how just removing the couple of bolts that attached the MC to the ABS module would have any affect like this.

 

Sounds like a possible bad brake hose (internally collapsed). Did you by chance put a pair of vise grips on the hose when you swapped out the calipers to stop fluid from coming out during the process ?

 

Hey Jeff,
I have since called the guy and double checked about this but he says not and the calipers were not replaced because he said they were fine. He just cleaned them up and make sure the pistons were moving freely.

 

Could heat be getting to the fluid/lines/master?

 

I doesn't appear so Mike. In checking the fluid right after shutting down, it wasn't above normal temp in the reservoir but in the lines? Maybe, but I don't see how.

 

if the calipers weren't replaced I'd pull them off and check tho see if the pads move freely in the caliper brackets. I've had quite a few sets that had to much paint on the pads that caused them to stick and not move freely. That would cause the brakes to hang up .

 

I am somewhat surprised to hear that. I don't know anything about modern Honda ABS, but I guess I just assumed they were all functionally fairly similar from brand to brand.

Just throwing it out there- does our ABS module have to be cycled / bled with a plug in computer? I think many do have to be cycled after removal to get air out of the ABS side of things. Wouldnt think that would cause your type of issue, but just figured I'd throw it out there.

 

This sounds about right. The rubber brake line that goes from the frame to the caliper goes bad and collapses internally, not allowing the pressure to be released. I have run into this several times on old cars. The hardline that connects to the rubber line is usually a pain to get off. Heat up the nut with a small torch or immersion gun and it will loosen easily.