Need Help Troubleshooting Brake Bleed
#1
Need Help Troubleshooting Brake Bleed
Rebuilt rear drums about 2 years ago (but only about 50 miles, shoes have full thickness). Adjusted drums to where drum barely slides on and wheel barely does one rotation when spun mildly by hand. New master, same time as the rears. Just installed an inline tube combo valve and line/hose kit (fit great). New front calipers with old pads (still have 5/16"). Re bench bled master, bled system twice now (first bleed I used an electric vacuum pump to pull fluid through, second bleed I used a one-man jar and pumped the pedal, refilling master as I went - solid fluid out all four corners.) Did back-up adjusting about 50 times.
Have brakes, but the top inch or so of the pedal is slack, and the rest feels off - like the first half of the pedal isn't really doing much.The pedal doesn't bottom out before the car stops. If I jab the brakes at 30 mph, they don't lock up but car stops softly. Really, the brakes "work" but the top of the pedal feels wimpy and I'm not confident that if I had to jam on the brakes, they would function as they are supposed to, especially if I had more passengers in the vehicle.
Troubleshooting, I checked the booster valve, the can holds vacuum, and the pedal drops when I start the engine as well. I clamped all three hoses and the pedal is brick hard except for maybe 1/4" of pedal slop. So, I presume that means that my problem is somewhere at the wheels. I tried the pedal with the engine on undoing the clamp on each hose individually, and I can't really pinpoint it to either front/rear, or right/left. It's like there is a little slop from everywhere. If I had to guess, I'd say that it seems like there is more slop when I unclamp the front hoses, both R/L have about the same effect.
I'm thinking it's the worn pads, and if I get some new, full thinckness pads it will take up the slack? Any thoughts appreciated? TIA - mark
Have brakes, but the top inch or so of the pedal is slack, and the rest feels off - like the first half of the pedal isn't really doing much.The pedal doesn't bottom out before the car stops. If I jab the brakes at 30 mph, they don't lock up but car stops softly. Really, the brakes "work" but the top of the pedal feels wimpy and I'm not confident that if I had to jam on the brakes, they would function as they are supposed to, especially if I had more passengers in the vehicle.
Troubleshooting, I checked the booster valve, the can holds vacuum, and the pedal drops when I start the engine as well. I clamped all three hoses and the pedal is brick hard except for maybe 1/4" of pedal slop. So, I presume that means that my problem is somewhere at the wheels. I tried the pedal with the engine on undoing the clamp on each hose individually, and I can't really pinpoint it to either front/rear, or right/left. It's like there is a little slop from everywhere. If I had to guess, I'd say that it seems like there is more slop when I unclamp the front hoses, both R/L have about the same effect.
I'm thinking it's the worn pads, and if I get some new, full thinckness pads it will take up the slack? Any thoughts appreciated? TIA - mark
Last edited by adis; November 17th, 2018 at 09:56 AM. Reason: clarification x2
#2
My thought would be, assuming all worked well prior to latest repairs, a need to first look at what was recently done ==> Just installed an inline tube combo valve and line/hose kit (fit great). New front calipers
#3
thanks for the reply, Dave. that's some good K.I.S.S. advice. i'm focusing on the calipers because the pedal is hard when i clamp the hoses,which leads me to believe that the lines are bled correctly. i bought a new set of pads, but i'm not going to put thm on because i took a look at the old pads and there's plenty of meat on them. at rest, the piston is about 3/16" out of the bore on both sides, rotors are 31/32"(d) and 30/32" (p). bleed screws are on the up side.
my current theory is that there is air in the calipers and i just havent been patient enough to get it all out. i'm going to let gravity and time have a crack at it. dont know if that'll do the trick, but im out of ideas...
my current theory is that there is air in the calipers and i just havent been patient enough to get it all out. i'm going to let gravity and time have a crack at it. dont know if that'll do the trick, but im out of ideas...
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brettb
Brakes/Hydraulic Systems
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October 27th, 2013 06:04 PM