R_CK_R

Hi Guys,

I got a big problem with my brakes. Had almost the same problem 1,5 yrs ago... If my Car is rolling my braking pedal is going slowly to the ground but if my car stands still the pedal does not move.
Last time I fixed it with a master cylinder kit. This time I tried just to bleed the brakes but it didn't work.
Do you have any ideas what my Problem could be?

Season starts soon and my car has to run.

PS: All wheel cylinders are dry.

Greets Kai

MDchanic

Sure sounds like a master cylinder.

I'lll let an expert on the older cars chime in.

- Eric

Professur

When it's not rolling, is the pedal hard or spongy?

R_CK_R

When it's not rolling the pedal is hard and the pressure is ok.
When it's rolling and the pedal goes to the ground you have to hit the pedal a little harder and maybe pump a few times to get the car stopped.

Octania

That's weird. Are the rear shoes adjusted out nicely?

"This time I tried just to bleed the brakes but it didn't work."
========================
Bleeding failed, or bleeding was performed OK but did not resolve the issue?
Even so, air in the system should bring spongy pedal at all times, not differing with moving vs. stationary.

barnfind

What type of brake set up do you have? Stock, from another vehicle, or custom ,power or manual? It does sound like a bad master cyl.

R_CK_R

I think it is the stock manual brake system...

Rocketowner

I don't understand what difference rolling or sitting still would be, but usually brake pedal going to the floor when holding pressure for very long,the problem is in the master cylinder.
Larry

barnfind

Have you ever replaced the rubber lines ? The layers of rubber break down over time and cause problems. The rolling vs stopped is strange

jag1886

If you have no leaks you need a M/CLD.

R_CK_R

I replaced everything inside of the master cylinder with one of these repair kits. After that it worked for about half a year...


Sorry, what is a M/CLD?

rustyroger

M/CLD is probably master cylinder.
I have had very limited success with rebuilds kits, I suspect yours need re-machining and sleeving, or replacing with a new one.


The posts referring to rubber lines were talking about the flexible hoses.


If you have slack wheel bearings it may account for your OK when stationary/spongy when moving brake pedal.


Roger.

MDchanic

Exactly.

- Eric

barnfind

[QUOTE=rustyroger;680855]M/CLD is probably master cylinder.
I have had very limited success with rebuilds kits, I suspect yours need re-machining and sleeving, or replacing with a new one.


The posts referring to rubber lines were talking about the flexible hoses.


X3 ON ABOVE

Yes the rubber lines are on the front of your car. Attached to the front wheel cylinders. Over time they break down inside and can bulge/ and or collaps when the brake pedal is applied. Your problem is the master cylinder, however the vintage of your car also automatically brings up the question in my mind about the soft lines. (better safe than sorry) The lines are easier to do while the master cylinder is out especially if its unknown the last time they were replaced.

R_CK_R

[QUOTE=barnfind;680955]
Ah okay, now I think I understand... Do you mean the brake hoses which go to the wheels?
I can not look inside of them but from the outside they look okay. I was thinking about to replace them all and maybe I replace the complete brake stuff...

barnfind

Yes, any soft lines in the brake system.

rustyroger

[QUOTE=R_CK_R;681040]
Rubber breaks down over time, there is an ongoing thread concerning old tires, perhaps rubber brake hoses should get the same attention.
It's just occurred to me, my car may well have 25 year old brake hoses. Now I'm scared to drive it.......


Roger.

Professur

I don't know about cars this old, but all the solid axle cars I've been under have another rubber brake line that goes from the hard line feeding the rear to the T block on the axle. They're all the same age. Just bad math to leave one while changing the rest.

Rocketowner

R CK R,Kanter has master cylinder for $130 and a complete three line set of brake hoses for $34 + Shipping. Replace these check everything else (brake shoes and springs, wheel cylinders) .Then you should have no worries. This is your Life and maybe someone else's. Best of luck. Larry