Jesse_Wenting
Old Thread Reviver
So around 2 years ago I realized my parking brake wasn't holding my 98 K1500 in place when parked on a mild grade. She's an auto and I never use it but brakes is brakes and I don't skimp on safety. Ended up becoming a front to back brake job. Literally the only thing that didn't get replaced at the rear was the backing plates. Up front I replaced both callipers with ACDelco remaned units. All the hard lines and flexible hoses were done, swapped my a hydroboost unit from a 99 K2500 6.5td
Obviously the brakes and power steering lines were extensively bled after all this. I was able to get a good pedal feel and for around a year it was great. I started having an issue where if I were to sit on the brakes for a few seconds (like at a red light) the vehicle would stop, but the pedal would then slowly sink to the floor until the ABS bypass valve opened. I bled the brakes again and got a good pedal feel back, but I would still have this issues if applying the brakes for an extended period of time.
About 4 months ago I replaced my master cylinder reservoir cap seal (the old one looked was really wrinkled, like the fluid had gotten stupid hot) and when I did the pedal felt as good as it did after I had originally bled the system. Since then I've gotten to the point where my pedal will be at the floor with the ABS bypass valve open any time I need to come to a full stop. I took my ol' girl to my local dealership and had them specifically bleed my ABS with a TechII, pedal was decent again right after but less than 30 minutes later is was back to how it was before the ABS bleed. Apparently they got "a few good burps" out of the ABS.
I'm honestly at a loss at this point. I've started playing with the possibility that the callipers I got are low drag style, but if that were true how could I have achieved such a good pedal feel initially? I have noticed a little fluid on the master cylinder since I went to the dealership, appears to be coming from the reservoir seals. No leaks at any fittings or hoses, and all my bleeder valves are tight. Any ideas are greatly appreciated, sorry for the long read.
Obviously the brakes and power steering lines were extensively bled after all this. I was able to get a good pedal feel and for around a year it was great. I started having an issue where if I were to sit on the brakes for a few seconds (like at a red light) the vehicle would stop, but the pedal would then slowly sink to the floor until the ABS bypass valve opened. I bled the brakes again and got a good pedal feel back, but I would still have this issues if applying the brakes for an extended period of time.
About 4 months ago I replaced my master cylinder reservoir cap seal (the old one looked was really wrinkled, like the fluid had gotten stupid hot) and when I did the pedal felt as good as it did after I had originally bled the system. Since then I've gotten to the point where my pedal will be at the floor with the ABS bypass valve open any time I need to come to a full stop. I took my ol' girl to my local dealership and had them specifically bleed my ABS with a TechII, pedal was decent again right after but less than 30 minutes later is was back to how it was before the ABS bleed. Apparently they got "a few good burps" out of the ABS.
I'm honestly at a loss at this point. I've started playing with the possibility that the callipers I got are low drag style, but if that were true how could I have achieved such a good pedal feel initially? I have noticed a little fluid on the master cylinder since I went to the dealership, appears to be coming from the reservoir seals. No leaks at any fittings or hoses, and all my bleeder valves are tight. Any ideas are greatly appreciated, sorry for the long read.