Bleeding Brakes - Off-Road Forums & Discussion Groups
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post #1 of (permalink) Old 05-05-2007, 04:13 PM Thread Starter
Can't Get Enough
 
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Bleeding Brakes

1979 CJ-7 manual disk. O.K. I've looked at the books and I just don't get it. The MC pooped itself, got the brake indication light. New MC. What's the deal with pushing that little pin in the front of the combination/proportioning valve???? I have no leaks, good firm pedal, no bleed down, no pulling. How the hell do I get the light to reset?

Today's mighty oak is just yesterday's nut that held its ground!
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post #2 of (permalink) Old 05-05-2007, 04:41 PM
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Inside the Combination valve is a differential pressure sensor. All this is is a piston that moves if there is a difference in pressure between front and rear brakes. See Attached cutaway of a Combination valve look for "Differential Piston. A differential pressure is Created when you bleed the brakes. What can happen is that the piston gets stuck and needs to be forced to the center by pushing in the pin to reset.

The manuals say you need a special tool, but I have had good luck using a C-clamp.
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Wilhelm

I will start using Metric only when the duodecimal system is adopted!!
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post #3 of (permalink) Old 05-06-2007, 11:42 AM Thread Starter
Can't Get Enough
 
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Thanks for the info. The pin has to be pushed in while bleeding the brakes. I made an angle bracket that slips under the head of one of the mounting bolts for the prop/comb. valve.

Today's mighty oak is just yesterday's nut that held its ground!
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