1978 Pontiac Bonneville - Brakes 'n' Stuff - Part 2 - 2008-05-17

Even after bleeding the master cylinder and brakes, they were still soft and mushy. Rather than deal with the lack of brakes, it was time to do something about it.

New master cylinder from CarQuest. $40. Very nice unit, no bubbles or anything after a few good pumps on the bench to bleed it. It installed easily and the brake light went away instantly. The brakes are very sensitive and responsive now. Safety for the win!

After brakes were done, it was time to get the rest of the car up to date. I drove it around for a few weeks and it delivers around 12-13MPG. It is very sluggish though. Doesn't really drive like a v8 car. Stumbles and hesitates pretty badly, doesn't like to do more than 65MPH up hills, etc. I investigated it. A new fuel filter was sought to replace the in-carb paper one. The old one was black and nasty, probably hadn't been changed in years. New breather filter, fixed leaks in the charcoal cannister purge, new tires (a bonus). Nothing really seemed to do it. It always felt like it was held back. Out at Steve's place one weekend I found an EFE valve on the ground in a pile of parts. I inspected it and found that the default EFE position is open. If the valve fails and vacuum doesn't do anything, it is heavy-duty spring loaded to open up. Well the one on this car is tied against the default position. Which means it is CLOSED. Choking off the exhaust to allow 8 cylinders to dump into the space of 4. Fine when the car needs to warm up, bad when the car IS warmed up and needs the space. I took a pair of dykes and cut the wire off and it opened right up to the default position.

Yeah, the blurry thing is it. The lever is all the way over, which means the valve is open. No exhaust restriction here. The kicker about this whole deal is the valve WORKS just fine. Why would someone tie shut the valve? It can't possibly help emissions since all of the emissions have to go through the passenger side rather than the driver's side to get out. It probably contributed to the failure of the exhaust valve in cylinder #5 too. What's even better is that when the valve IS closed by the emissions control system, it is closed MAYBE 60% of the way, if that. Not 100% like the wire was doing. I don't understand some people...

While I am being generous, let's fix the radio wiring harness. New soldered connections are great. I also fixed the cigarette lighter and replaced the blown 5A fuse with the proper 20A fuse. The car has the courtesy light package which lights up the kick panel and footwell area when the lights are turned on. It's nifty and runs off of this particular part of the fuse block while the overhead and rear courtesy lights run off of a different circuit (for some reason, perhaps to indicate a blown fuse).

New washer pump. It is nice to have the little things work in a car like this.

With an unrestricted exhaust the car is a different animal. It takes off from the line, has no problem doing 70-75MPH and perhaps may just get better slightly fuel economy. Ridiculous what people who don't understand how a system is supposed to work will do to it to cause it to perform even worse than they thought it was. I did some more maintenance and checked the reservoir on the power steering pump. Dry as a bone. Leaky hoses. Made a mess of the front end and allowed the pump to run dry. Quite annoying, but what you gonna do? Replace the hoses and top off the reservoir is what you do!

Return to Main Page

Last updated May 17th, 2008