Lost all pedal with brakes

[John Tipps]

Ok Ill try to post all the details as to maybe keep the back and forth to a minimum so forgive me for the long post...

1. My 66 Chargers front brakes were upgraded to disks from an E body years ago and both calipers were left hand units-the right was made to work with extra long hose (I know unsafe)
2. Had my front end aligned and the Tech reminded me about it, so I decided to change the caliper on the right to the correct RH unit from Autozone to be safe
3. Installed it and everything seemed right, bled both fronts to be sure (changed both banjo hoses and copper seals) and made sure all was snug, very little air came out of both sides
4. Started to take for a test drive and went all the way to the floor, could pump and pump and might get a couple inches of pedal but would disappear immediately
5. Thought the wife may have let the pedal up before i closed so we bled again and no air at all and also made sure she pumped it correctly, exact same results no pedal at all except the 2 inches then gone
Being as though no air bubbles came out after 2 correct bleeds and no rear brakes at all (dual master) could my master cyl all of a sudden fail? Would the new caliper be bad even though it held no air and would that cause it to go to the floor? The hoses show no signs of leaking whatsoever... I would appreciate any help

 

[Aron Gleason]

Did you bleed the master cylinder?

 

[John Tipps]

No it was never dry

 

[pnora]

Are the bleeders on the top?

 

[John Tipps]

yes

 

[John Tipps]

Gotta get off for now, Ill read any help in the morning thanks for the help

 

[Mopars & Missiles]

Piston seized in the master, happened to me once and acted like what you describe. Pulled my hair out for several days trying to figure out the problem thinking it couldn't be the master. Finally took the master off the firewall and looked into the bore and sure enough, the piston was seized almost all the way to the bottom of the bore. Pump all day and nothing was going to happen except my leg would get tired.

 

[1 Wild R/T]

What master cylinder are you using?

Pretty common for an old master cylinder to fail after bleeding brakes... The area of the bore where the piston doesn't normally travel gets coated in crude/sludge and when you bleed the brakes the piston travels in that area & the seals get damaged...

 

[John Tipps]

Master cylinder is from a 72 chevelle, nonpower

 

[John Tipps]

Master cylinder has a lifetime guarantee. I’ll remove it tomorrow and take it back and get a replacement.

 

[John Tipps]

It’s been on the car for 14 years with little use, you’re probably right

 

[John Tipps]

Piston seized in the master, happened to me once and acted like what you describe. Pulled my hair out for several days trying to figure out the problem thinking it couldn't be the master. Finally took the master off the firewall and looked into the bore and sure enough, the piston was seized almost all the way to the bottom of the bore. Pump all day and nothing was going to happen except my leg would get tired.

Master cylinder has a lifetime guarantee. I’ll remove it tomorrow and replace it. Thanks for your help.

 

[John Tipps]

I replaced my master cyl and bench bled it, had to use dot 4 instead of what was in it (dot 5) couldn't afford the dot 5 which was 27.00 for a half pint and that's all I could find so I flushed the entire system with 4 and still it's the same scenario- peddle goes to floor, pump it and it comes up couple inches wait few seconds push again and back to the floor- I've completely bled the system 4 times in all and there is no air in the system, the master was bench bled when new and twice with the tubes on the car and the bled system completely each time- no air is in the lines. Is it possible I have some kind of damage going from dot 5 to dot 4?

 

[jimbosride]

I don't think going from 5 to 4 fluid is the issue. Have you checked that all brakes are locking with the pedal down? Maybe a stuck caliper/piston?
I use a pump vacuum bleeder so I never had this kind of issue.

I found this older post that may help? .

Need Help Getting a firm pedal

 

[pnora]

Your problems started with the replacement of front calipers. Put up some pictures of both front brake set ups.

 

[John Tipps]

Away from the shop now I’ll get them up then tomorrow thanks

 

[John Tipps]

So it was the position of the caliper bleeder that was holding air, as stated their off E body 70-74 and went on my 66 B body conversion- thank you guys!!

 

[pnora]

So it was the position of the caliper bleeder that was holding air, as stated their off E body 70-74 and went on my 66 B body conversion- thank you guys!!

So the bleeder was on the bottom of the caliper trapping air.

 

[John Tipps]

Yeah I’m sorry I wasn’t clear- it was the the bleeder screw too low to properly exit the air, I removed both calipers with the hoses attached and sat them on the tie rods with the screws pointing straight up, loosened the bleeders and gots lot of air. Thanks for the advice

 

[pnora]

Yeah I’m sorry I wasn’t clear- it was the the bleeder screw too low to properly exit the air, I removed both calipers with the hoses attached and sat them on the tie rods with the screws pointing straight up, loosened the bleeders and gots lot of air. Thanks for the advice

If installed correctly the bleeder screws will be on top so no need to remove. Sounds like your set up is a mixed bag of parts. However you can bleed them the way you described.