Now that the mechanical side of the steering system is done, the hydraulic side can be figured out. This requires a discussion of the brake system. The 1996 vacuum booster was removed for two reasons: There is no vacuum source on a diesel engine to run a large vacuum booster and it was in the way of the engine. GM diesel vehicles have come with a “Hydraboost” hydraulically assisted brake actuator for decades and this 2012 was no exception.
In typical GM fashion, the hydraboost and vacuum booster use the same interface to the firewall so this part literally just bolted in.
The firewall on the van was vertical whereas the firewall on the Buick has a bit of an angle to it, therefore the master cylinder and reservoir on the 2012 won’t clear the 1996 hood. Unfortunately the master cylinders didn’t have the same interface so some modification was necessary.
First the master cylinder was disassembled so no machining chips damaged any parts or seals
The bolt circle lined up, however the pilot diameter of the 1996 master cylinder was too big for the 2012 actuator. There was a center drill on the end, but other side needed to be turned down so a new pilot was turned on the opposite end so the mating side could be turned down to fit inside the actuator.
Now that there’s a centered place to chuck in the lathe, the other end needs to be centered so it can be turned down. The live center on the lathe wasn’t big enough so a conical adapter was used.
Once all the machining was done, the whole thing was assembled and installed – fits like a glove. Back to power steering…
Now the hoses/tubes can be run for the power steering circuit. Between all of the 1996 and 2012 hoses and tubes, no new ones were needed, just a couple bends and a splice.
Again, thanks for reading – please post any questions, comments and suggestions below. Next up – Brakes!
Fix Until Broke 