New To Me ~ 1990 Suburban 3/4 ton 4wd with a similar combination valve stuck / poor brakes / brake light on.
No visiable brake fluid leaks. *** At some point a Dana 60 Full FLoater rear axle was swapped in, but it is a clean swap and has been in place 10+yrs (talking to a friend who was po's state inspector and a fellow chev truck enthusiast). Truck has 8" of lift and 36" Swamper TSL Radials.
Bled brakes / gravity bled / Reverse bleed from the rear with Phoenix injector pump ~ have flow but low pressure, not able to correct stuck combination switch.
Also reverse bleeding was spraying a squirt gun stream of brake fluid out of the top of the MC ~ (Cover off). This is not normal ~ been using this pump for 5+ yrs. I will try to snag a used combination valve Monday and also try the aforementioned above stomping the pedal 10x quick, along with disassembly and recentering if it comes down to that.
Pic of my funny looking combo valve and I believe that is Generation 1 ABS just behind it. My lines come in and out of the combo valve in a H pattern the lines right and left are what I believe to be rear ABS. Does ABS complicate things?
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