Author Topic: Front brakes  (Read 1883 times)

Offline Cheyenne1010

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Front brakes
« on: June 20, 2018, 11:32:20 AM »
What's up guys,I got 1973 chevy C10 long bed.When I'm driving straight the brake pedal is firm and brakes response is quick.when I make a left or right turn and press the brake pedal it'll go to the floor,then I'll pump the brake pedal once and it'll be firm again.a friend told me to get the pedal firm and remove brake master cylinder cover and turn the steering wheel left or right,I turned right and I seen a little brake fluid stream shoot up from reservoir then I pressed on the brake pedal and it went to the floor,samething happend when I turned left.everything that has to do with the brakes have been replaced with new parts and new front brake rotors with new inner and outer bearings.now if I do the samething with the truck Jack up it doesn't do it,I turn left and right then press the brake pedal and it's firm,I put the truck back down,turn the steering wheel pedal goes to the floor.i know there's something pushing the caliper piston back into the caliper but I just don't know what it is.any help is welcomed.have a nice day guys.

Offline 75gmck25

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Re: Front brakes
« Reply #1 on: June 20, 2018, 11:45:01 AM »
Did you replace the calipers and the flexible front brake lines?   Since it happens when turning, something is changing when the wheel is turned, and the first suspect would be the flexible lines.

Bruce

Offline Cheyenne1010

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Re: Front brakes
« Reply #2 on: June 20, 2018, 01:31:04 PM »
Flexible rubber brake lines on both sides have been changed

Offline VileZambonie

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Re: Front brakes
« Reply #3 on: June 20, 2018, 08:17:19 PM »
hydro-boost or vacuum booster?
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Offline Cheyenne1010

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Re: Front brakes
« Reply #4 on: June 24, 2018, 08:13:35 PM »
Vacuum booster and its new

Offline Henry

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Re: Front brakes
« Reply #5 on: June 25, 2018, 01:40:07 PM »
Hi Cheyenne:
When you are not moving and you turn the wheels and then press the brake pedal does it go to the floor like when you are moving? What happens when you are not moving and steering straight ahead and hold the brakes down and then turn the wheel while the brake pedal is held down?
Regards,
Henry

Offline Cheyenne1010

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Re: Front brakes
« Reply #6 on: June 25, 2018, 08:34:01 PM »
 when I have the truck jacked up and turn the wheels right and/or left the pedal is fine and it's firm and doesn't go down to the floor. then I put truck back on the ground with steering wheel straight and not moving, turn the steering wheel right then left push down on the brake pedal and it'll go down about 1 inch above the floor,then I'll pump the pedal once and it'll be good. I can drive straight for a mile or 10 miles and hit the brakes and they will work every time,but if I turn left or right then press the brake pedal it'll go down and not really slow the truck down,until I pump the pedal once and the brakes will work fine.I have not tried turning the wheel left or right while I press the brake pedal.(one other thing I forgot to mention is that the truck sat for ten years with about 900 to 1200 lbs.of trash in the bed of the truck).is there any chance that the front spindle's could've weakened over the years with all that trash in the bed of the truck and maybe the spindle's are flexing causing the brake rotor to push on the brake caliper piston forcing brake fluid back to the master cylinder.
« Last Edit: June 26, 2018, 10:43:59 AM by Cheyenne1010 »

Offline Irish_Alley

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Re: Front brakes
« Reply #7 on: June 26, 2018, 08:00:58 AM »
not sure if it can help but it cant hurt

take a read here
Brake System and Diagnosis
If you can’t tell yourself the truth, who can you tell it to?~Irish_Alley

When you have eliminated the impossible, whatever remains, however improbable, must be the truth ~Sherlock Holmes

Offline VileZambonie

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Re: Front brakes
« Reply #8 on: June 26, 2018, 06:24:02 PM »
Make sure you don't have the caliper hose twizzlered i.e. the caliper flipped around so the hose twists.
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Offline Cheyenne1010

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Re: Front brakes
« Reply #9 on: June 26, 2018, 09:15:28 PM »
Calipers are in the correct position and the brake lines are not twisted.the only thing I can change is the spindle,I know the spindle is a hardened piece of metal and shouldn't flex but I think the truck sitting for all that time with all that weight in the bed might of weaken the spindles.everything is new on that front end except for the A-arms and the spindles.I'll be back with an update,thank you guys for the replies,this site really offers alot of help.

Offline Cheyenne1010

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Front brakes
« Reply #10 on: September 17, 2018, 04:49:04 AM »
Hey guys its Cheyenne1010,some of guys might remember my post about my front brakes going to the floor after i make a left or right turn,well i found the problem and fixed it.
   I had bought front brake rotor with the race pressed in them and bought new bearings that came with their own race.when i installed the new bearings i didn't install the race that came with them,because i figured the race that were pressed in the new brake rotors would work with the new bearings i bought and i was wrong.the bearings didnt seat in the race that were on the rotors,so when i made a left or right turn the rotor would move and press against the brake caliper piston pushing the brake fluid back to the master cylinder,so when i would press the brake pedal there wouldn't be any brake fluid pressure in the line so the brake pedal would go to the floor.
   So i bought new bearings and new race.i pressed out the race's from both brake rotors and pressed in the race's that came with the bearing.i packed the new bearings with grease and installed them.i took a test drive and the brakes work perfectly going straight,making left or right turns.
  My mistake was that i trusted the part store would sell me bearings that would fit the race that were pressed in their rotors,lesson learned.thank you guys for your time and inputs.

Offline Henry

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Re: Front brakes
« Reply #11 on: September 17, 2018, 12:30:10 PM »
Hi Cheyenne1010:
Glad to hear you got your problem solved and thanks for taking the time to explain the cause...some more useful info in diagnosing brake problems!
Regards,
Henry