Chrysler Repair: 1985 Chrysler New Yorker, chrysler new yorker, vacuum line

Question
My mother-in-law is giving my wife a 1985 New Yorker. The vehicle has about 200,000 miles. It is a 4 cylinder with a turbo. It has not been driven much since my father-in-law passed away. It has a vacumn leak at the brake booster or a possible bad booster. You can hear it hissing when you apply the brakes. I also had the ignition on/off/on/off/on sequence checked to get the diagnostic codes. I hope the codes are accurate. I am in South Carolina and I am working through my brother-in-law, who is in Tennessee.

1st question.
Could the vacumn leak at the brake booster cause the vehicle to loose power and the loss power light to activate?

2nd question.
When the diagnostic codes were checked the loss power light flashed in the following sequence.
one flash, pause
two flashes, pause
five flashes, pause
five flashes, pause
What kind of problem does this code indicate.

Thanks,
Tom


Answer
Hi Tom,
Yes, if there were sufficient vacuum leakage to perturb the operation of the Manifold Absolute Pressure sensor then that might not only cause the power loss light to illuminate but also to set a fault code, either a 13 or a 14. A severe vacuum loss could also cause the engine to loose power due to an inappropriate mixture of fuel and air. But I see that you only read a 12 and a 55 code which mean, respectively, that the power from the battery to the controller memory was disconnected recently (but that doesn't cause a power loss light), and the latter code means "end of code readout". So there is some ambiguity between the light being on and a code in the memory that doesen't turn on the light.  If the battery hasn't been disconnected recently, then I would inspect the battery posts to verify they are shiney and clamped tight. On the brake booster, check the hose attachment and clamp and if that doesn't stop the hissing, then replacing the unit might be in order. But if the power brakes seem to be effective, a leak in the vacuum line might be the real problem. Check both ends of the vacuum line as well as the thin vacuum line that branches off of it and goes thru the firewall which is used to operate the air distribution doors of the heater. It can be cracked or loosely connected also; and you might be hearing that sound of a vacuum leak in the cabin due to the loss of vacuum in the thin line from the vacuum brake unit to the heater air distribution door unit inside the cabin.
Roland