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is there a brake master check valve?

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artmck

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My brake pedal goes to the floor if only light presuure is applied. This makes me thing there is a check valve that does not seat well under low pressure. Any ideas?

Thanks
 
Might need to bleed the brakes? Did you check your brake fluid level?

But then again, what do I know? /ubbthreads/images/graemlins/jester.gif I'm sure some of the guys here will have the right answer for you!
 
There is a break manifold mounted on the driver side engine well. But, first, check your fluid levels and blled your breaks. If that proves fruitless, it may be the manifold. If so, I'm sorry. Those bears are expensive $400-500 US. I've never heard of anyone repairing them.LOL /ubbthreads/images/graemlins/hammer.gif
 
They are fine when you hit the pedal hard, only when you are light on the pedal does it go soft. I need to have someone watch the reservoir to see if it pushing fluid back into it.
 
Sounds like the Master Cylinder needs a rebuild Artmck.---Keoke--??
 
[ QUOTE ]
They are fine when you hit the pedal hard, only when you are light on the pedal does it go soft.

[/ QUOTE ]
It appears that the MC cup is not fitting/sealing tightly or uniformly enough to the bore. Under light application there is not enough pressure to expand the cup for a seal. Heavier more sudden pressure expands the cup so that it seals.

Reasons could be that the cup is undersize or somehow installed wrong, the bore is oversize, or the bore is scored, or the edges of the cup are damaged.
D
 
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