Continuous mushy disc brakes

[69camarokid]

69 camaro.
11 inch power discs all four corners
OK so heres the senario.

About 3 months ago the brakes started to get really mushy.
Turns out that one ofmy rear brake lines had snapped off the end section that allows it top seal and keep air out. So i replaced that part and bled the brakes. They felt solid with the car off, once it was on they went mushy again.

Thats when i noticed the master cylinder was leaking. So i just replaced that this morning with a new one, then proceeded to bleed the brakes. The pedal felt solid after, then i started the car and it went straight to the floor mushy again. Ideas?


Here is one question i have. when i bled them the second time i noticed in the rear not a single gurgle or bubble cameout, just steady streams of power steering fluid. This was after 6 or 7 pushes of the pedal. In the front on the passenger side i got lots of air, nad then finally steady streams. Left front was nothing but steady streams.

Any ideas on what may be causing this? thanks

[Chad-1stGen]

If you replace the master and never got air to the rear then something is wrong. Most likely you didn't bleed it enough. How many times was the pedal pumped or how much fluid did you run through when you started at the passenger rear before moving on?

Also I'm assuming the power steering fluid comment was a type but if it wasn't then that is also a problem.

EDIT: Did you bench bleed the new master?

[CarlC]

Ditto on the bench bleed.

[Thumpin'66]

69 camaro.
11 inch power discs all four corners
OK so heres the senario.

About 3 months ago the brakes started to get really mushy.
Turns out that one ofmy rear brake lines had snapped off the end section that allows it top seal and keep air out. So i replaced that part and bled the brakes. They felt solid with the car off, once it was on they went mushy again.

Thats when i noticed the master cylinder was leaking. So i just replaced that this morning with a new one, then proceeded to bleed the brakes. The pedal felt solid after, then i started the car and it went straight to the floor mushy again. Ideas?


Here is one question i have. when i bled them the second time i noticed in the rear not a single gurgle or bubble cameout, just steady streams of power steering fluid. This was after 6 or 7 pushes of the pedal. In the front on the passenger side i got lots of air, nad then finally steady streams. Left front was nothing but steady streams.

Any ideas on what may be causing this? thanks

Did you mean to say power steering fluid or brake fluid??

[69camarokid]

meant brake fluid, sorry.

also i did not bench bleed the new master. Just hooked it up and went. Looking up on google now what bench bleeding is

[salem1912]

Ck for bearing play, loose bearing will push pistons back as you ride down the road.

[TnBlkC230WZ]

If you have power brakes, you must bench bleed the MC. You definitely still have air in the rear line if you didn't get any out during your bleeding process. Keep bleeding the rear till you get some air. If you fluid coming out of the bleeder doesn't look completely clear (like new fluid), you haven't bleed enough.

[69camarokid]

If you have power brakes, you must bench bleed the MC. You definitely still have air in the rear line if you didn't get any out during your bleeding process. Keep bleeding the rear till you get some air. If you fluid coming out of the bleeder doesn't look completely clear (like new fluid), you haven't bleed enough.

finished bench bleeding the master cylinder and now im waiting on my dad to come over and help me brake bleed the system.... for the third time. ugh.

ill let you guys know how it goes

[04ctd]

bum borrow rent steal a "power" bleeder.

i used one that worked on venturi system with compressed air.

it just sucks the fluid thru, instead of pumping it.

took a whole Big (quart?) bottle of fluid to do all 4 brakes on my nova.

[MonzaRacer]

http://www.brakebleeder.com/index.php?main_page=index&cPath=2

Now these devices REALLY make bleeding easy. I am a Master Certified Auto tech and have used Phoenix Systems for years. Found them in trade mag I think, bought one off tool truck and literally wore it out, well it still works but really could use new seals but its discontinued so I a MaxJect Pro back about 7 or 8 years ago,,, then back when I was going to drag race I wrote them, bragging about the tool, and the StripDip and was looking for stickers to go on car, figured I might get a couple.
Well fast forward to last fall, I was contacted and offered a free unit shown on add, sadly with out light mount but Iwill buy one later, if they could get a pic and use my testimonial email.
Heck new $370 tool that make my job easier, heck yes you can use it.
I can flush a brake system, reverse bleed brakes, and never look back.
I like the fact that if you have ABS, and blow a line, repair the line, bleed up to ABS controller and then connect it, and finish bleeding.
See all brake systems are made to allow free flow in release, so there are no ports blocked, and air LIKES to go up, remember laws of physics.
I have redone dozens if not hundreds of brake line replacements, as in when I find car with rusted lines I recommend replacing all lines, heck with my hydraulic flaring tool I can even reuse oddball fittings.
Reverse bleeding the systems, eve non car driven for days empty and so far havent had to replace very many master cylinders.
Heck I almost had a bad accident, after blowing one line on my Cavalier in a panic stop, then drove my car for like 4 or 5 days with no fluid in half of system.
This was second time rear lines had rusted off, so I was confident in driving with half of system.
Anyway the line that rusted out above the fuel filter, got it replaced, even drove to my brothers like another 15 miles, reverse bled my car and tada, no more bleeding needed.
Maybe 10 minutes laying in my brothers drive and its done.
Heck reverse bleeding takes less time than clean up.
I have even replaced complete systems, reverse bled them on car and tada, done.
OH and bench bleeding I have learned, works best with solid fittings blocking ports over the lines looped into the master cylinder.
As for the vacuum bleeders, they work in a pinch but honestly I have used them with less quality results.
Heck I have even used systems that you hook a line to bleeder and a vacuum to master cyl and they work great.
Good luck in your manual bleeding.

[Gordz32]

if u have a proportioningvalve make sure its open all the way and def. bleed that master.

[69camarokid]

bench bled the MC and then rebled all the brakes, for the third time. The brake pedal goes down aobut half way now but then gets firm. Much beter than before, but not quite where id like it.

[Vegas69]

Bency bleeding is crucial. It's especially crucial to do it with no leaks between the piston and the brake fluid. Meaning the fittings and hose you used didn't suck air back into the master piston

[JEFFTATE]

What kind of brakes ??
What kind of master cylinder , proportioning valve , brake lines , etc.. ???

Does it have one of the original residual pressure valve in line some where ????
They leak and let air in the system.
Does it have original hard steel brake lines ???
The lines could leak too and let air in ..

[406 Q-ship]

Do you get a good pedal while bleed and then the pedal gets "mushy" or do you have to drive the car then the pedal goes soft? If it is the later you may have a warped rotor that is pulsing the pistons allowing air back into the system. You said that you have four wheel 11" discs, off of what vehicle?

[69camarokid]

after bench bleeding and then regular bleedinghte brakes i am happy to say that i have relatively stiff brakes now! yah! they still go down about an inch before they get solid but they dont go the floor anymore and thats a big improvement