Suburban axle swap

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AuroraGirl

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Seems to me that you're blaming Bosch for problems created by the shop that didn't replace the proportioning valve(s) properly. But maybe there's just a failure in your ABS module.

An ABS system should have the ability to block fluid flow from the master cylinder (preventing increased pressure to the skidding wheel(s). It should also be able to relieve pressure in the hydraulic system so the skidding wheel begins to turn again. That's what the accumulator in the ABS is for. There's a blocking valve that's normally open, closes when signaled by the ABS "brain", and a relief valve that's normally closed, which opens to the accumulator when signaled by the ABS "brain". Maybe your rear relief valve is stuck shut, can't open to relieve pressure.

When the wheel turns again, the system may reapply pressure from the master cylinder. The intention is to keep that wheel's brake applied as much as possible without locking.

The old RWAL system had no separate fluid pump; as the system chattered the hydraulic system allowing fluid pressure/blocking fluid pressure/relieving fluid pressure via the accumulator/re-allowing fluid pressure, the brake pedal would sink as the accumulator filled. Newer systems run a fluid pump that keeps the brake pedal nice 'n' high while allowing/blocking/relieving/allowing fluid to the skidding brake.
Well bosch did create the thing. The bosch 5.3 which was used the next model year on my car till the end was superior in everyway. the unit was lighter, had more functions, had true 50/50 brake split with dynamic rear proportioning (No valves in the lines like mine has, it can utilize the rear disc brake to be as strong as possible given the size and weight transfer when braking. The unit was cheaper, too. Lol. Its just a technology advancing with the times thing. The bosch 5.0 was 3 channel .
however, i will give your argument a fair shake to being accurate, because the car cant properly do traction control either. When traction engages, you will actually come to a complete stop if you keep on the throttle, when it does the front brakes , adjusts timing, cuts to 3 injectors, the car will keep doing all that unless you get off the throttle, so maybe there is problems somewhere, because of the work that tech did, to be honest, i cant even be sure the lines are routed to the right ports. Wouldnt surprise me. Terrible worksmanship. He also totaled my rear discs and pads because he couldnt torque brackets down.


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this side was the wort, the one bolt fell out, pivoted the caliper and it then it wedged into the wheel and left a deep groove and locked the wheel, had to get out of traffic and into a parkign lot , thankfully the snow allowed the tire to ski most of the way without loud squealing on pavement.
He even ran one of the MC lines over the unit instead of the proper way around.. he also routed brake lines to be short so they go into threaded connections at an angle, and he placed them where they would be in the way of important bolts that OE routed around specifically.

I hate that guy.
 

Diptenkrom

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seems like a place to stay away from in the future... Thanks for all the info. will be starting to collect parts as soon as i get my other car back on the road. (suspension work that got drug out due to missing special tool, and shop press usage)
 
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