replaced master, still spoungy

[kevs250]

i just replaced my master cylinder on my 70 f250
i just bled them and they better buy still a little spoungy
when i first pump the pedal it goes to the floor, but when i pump it again it is perfect. soo do i still need to bleed some of the breaks?

[BobbyFord]

You still have air in the system. Bleed the right rear wheel first, then the left rear, right front and left front. Do not allow the master reservoir to become empty during the process. Make sure the rears have been adjusted with a brake spoon.

[jzjames]

& make sure you dont have the shoes installed backwards ( the rearward ones are larger) , and if the brake hoses are funky, it can cause probs.

[James72]

Did you bleed the master cylinder before hooking up the brake lines?

[bugser]

Did you bleed the master cylinder before hooking up the brake lines?

Uhoh??





I did that and still had to go back and bleed the lines.

[basketcase0302]

I did that and still had to go back and bleed the lines.

Yep, it'll happen.
Highly reccommend one of these to everyone:
http://www.mityvac.com/

Once you use one, you won't go back to the "shadetree" way of bleeding brakes.

Basketcase

[kevs250]

yaa that was my mistake
I didn't bench bleed the brakes.
soo should I bleed the brakes until air comes through??

[hotrod ford]

yes. first you should see bubbles and fluid then just fluid .

[James72]

Myself, I would disconnect the brake lines and use the kit that came with the MC and bleed it first, then the brake lines. Even though you've been bleeding and pumping the brakes already and it might be bled by now, if there is a bit of air in the MC it will go a lot faster if you bleed it first just to be sure

Also FYI, if you install an unbled MC and try to bleed the brakes with the engine running you run a high risk of blowing the piston out the end of the MC. So never bleed brakes with the engine running, trust me