highcking

The car does have a booster, integral with the MC.

I haven’t had time to look into the exhaust system. And now it’s cold. I may have my shop take a look soon.

Nat - Thanks! Does ATF smoke have an odor? How would the fluid get into a combustion chamber? Via a vacuum hose?

I’ll take care of the issue posthaste when I return home. Better than a head gasket replacement!

EmTee - thank you! That’s all new knowledge to me. I will check it out when I get home from a business trip. Bill

Final update and resolution. White smoke was water vapor from substantial water that had accumulated in the driver’s side exhaust train. This occurred over a period of month or more of variable but generally moist, cool weather during which the car was not started and heated up. My guess is that the water was in the front muffler on that side and possibly low spots in the piping. The passengers side is apparently configured so the water runs out or leaks through a tiny gap in a pipe coupling. As already noted, the combustion gas test was negative. Yesterday a long run of 30 plus minutes in temperatures in the 70s produced a lot of smoke at first and eventually none. It was warm last night, no chance for condensation. Started and ran/revved the car today and the billowing clouds were gone. Just a bit of water discharge on both sides as expected. I expect that in the future I’ll get water vapor again if weather conditions are right and the car sits for weeks at a time. I dodged a very unpleasant bullet. I’ve been around cars for some 55 years and have experienced two head gasket failures, one a previous 58 Buick! But I never encountered this “Steam” phenomenon. Thanks to all who contributed ideas and suggestions. Bill Shields

I plan on that drive as soon as the cursed leaking master cylinder has been replaced!

Bob - thanks, will do. I tested all the cylinders myself soon after I got the car about 100 years ago, it seems. I have the readings in a file somewhere. All were significantly down from a nominal 180 but their were no extremely low readings. I doubt this engine has ever been touched other than minor reports and tuneups. I’ll report what the shop finds.

EmTee - I looked at two plugs on the drivers side and they looked normal to me. The two rear plugs on that side are extremely difficult to pull out and replace. I’m taking the car to a shop soon for unrelated work and I plan to ask for a compression test on all cylinders.

Marty - no crossover on this model. Separate front to back.

Both possible … but they would cause smoke from both exhaust pipes. Everything is discharging from the drivers side only.

60FlatTop, New tool? Alas, I have an essentially brand new Stant test kit bought as Hershey a decade or two ago. I plan to use it along with Bob’s suggestion of the CO2 detector. In that case, I did have to buy a new tool. Now that I’m 72, I wonder where all these tools will end up.

Morgan - I live on a farm and mice do that kind of thing! Last year they built a big nest inside my pressure washer preheater. And recently I found a mouse nest inside the air cleaner of my Ram hemi engine. Buick has a muffler and two resonators on each side. I’ll explore that possibility.

Yes, that puzzled me at first. But it didn’t stop for long. Eventually it ran for 25 minutes steady, smoking on the drivers side only. Has to be coolant getting into a cylinder and vaporizing. I don’t see any sign that the oil is diluted. Or block damage …

My Buick's master cylinder came with a threaded steel plug where the brake light switch installs. I forgot to install the switch before I installed the master cylinder so I had to do it with fluid in the cylinder. I purchased a “Standard” brand in the box from an eBay vendor. I followed some online advice to prevent air getting into the system and this worked like a charm. I filled the switch with brake fluid, wrapped the threads in Teflon, and did the quick swap. A very small amount of fluid dripped into the shop rag. Now I come to my question. I was wearing rubber gloves and quickly turned the switch in with my fingers. After a few seconds of turning (maybe 3-4 full turns, I didn’t count) I suddenly realized the switch housing was turning but not the threaded piece. I stopped immediately, cleaned up the dripped fluid and ran a few tests. It’s not leaking even after depressing the brake pedal (engine off) 10 or so times. The switch itself works just as it should. I haven’t done one of these switches in a long time. Opinions on what happened? Defective switch from China? I can’t locate any specific directions on how to actually install the switch. Thoughts welcome. Note that the picture is generic - ignore the numbers. Bill in Virginia

See below, thinking of buying a salvage parts unit. The unit now on my car has a threaded plug where the picture shows a two-terminal sensor. What is this sensor? My wiring harness has no plug for a brake sensor. What would it be sensing?

@Oldtank - agree. Notified Fusick, let’s see what they say, if anything.

Added note. I heard from Fusick - I bought the unit from them on an exchange in 2020. I installed soon after receiving. My guess is that it leaked from the start. Very hard to see the leak unless you have reason to look for it. I was fortunate in checking the fluid level …

Bob - thanks. The diagram is much clearer than some others. I just snagged off of eBay the 1958 Moraine power brake manual! I’ll post anything helpful. The image you posted makes it clear to me that the leakage I’m seeing most likely originates at the final O-ring seal BA, just before the flange Gasket. At that location, leakage will slowly drain the fluid exactly where I see it, at the bottom of the flange. That will not affect brake performance unless the fluid level is allowed to drop a long way. (Which happened over probably two years). The engineering question that puzzles me is why some of these units leak and some do not. If you surveyed all 57 and 58 Buick owners still around, how many would report seepage at that location? Is seepage past that seal related to the material used in the O ring? Are all rebuild kits the same in that regard? If I buy a rebuild kit, I will take a very close look at seal BA. It probably needs to be an absolutely perfect dimension and made of a material not degraded by DOT 3 fluid. Anything that gets past it will soak into the paper flange gasket. Overall, the complicated set of seals and metal parts shows what a mistaken design this was (quickly realized). Bill

Old-tank, thanks for that link! I wondered about that. Phil - you almost have me convinced to DIY the unit. Bill

Understand. But I would be doing everything for the first time. If I get it back in and it still leaks, or doesn’t function properly, I’m looking at buying yet another costly rebuild. It’s odd … my first ‘58 which was an original condition, one owner Century with 50,000 miles on it, never leaked brake fluid in 15 years of owning and driving. This multiple-owner Roadmaster is somewhat cursed. After a year of fiddling, I just finished getting the Carter AFB tuned right using an exhaust gas analyzer. Idles and drives just fine. Now this. FYI to all 57-58 Buick folks - it looks like Fusick is the last visible vendor offering an exchange on these units.

My Roadmaster has the Delco-Moraine one piece power brake unit. About 4 years ago, I sent the unit on the car to a reputable rebuilder whose name I can’t seem to locate at the moment. As all owners of these units know, removing and installing the unit is not pleasant. Fortunately, the rebuild has performed flawlessly ever since. A few weeks ago, before taking the car out for a drive, I looked at the reservoir and found it virtually empty. That surprised me as the car leaks nothing on the concrete and there is no sign of leaking fittings. Today I did locate where the fluid is oozing out, very slowly, while the car sits. It’s a tiny trickle at the bottom of the triangular mounting flange of the master cylinder. Using an angle mirror, I can see that the Dot 3 fluid has eroded the paint on the bottom of the vacuum chamber. When I cleaned the area thoroughly, the fluid reappeared as a droplet or two within 24 hours. It takes about a week at this rate to lower the master cylinder level by an eight of an inch. I’m aware of the known problem with this unit leaking backwards past a seal into the vacuum unit. What puzzles me is that the fluid is actually escaping to the outside of the booster, not the inside. The overall unit continues to function extremely well. To the extent a little Dot 3 escapes into the vacuum chamber itself, several Buick commenters on other sites point out that it would be sucked into the intake manifold and burned up in an instant when the engine starts. For the time being, I plan to watch the issue and live with it unless the leak gets markedly worse. Observations?

Will do.

Bob - no, don’t know about him but I guess I should! My previous ‘58 Buick was a low miles original, never touched the tranny in it. Do you have any contact info, email or phone? I see his shop is in Perrysville, OH. Bill ps. I found what I think is his number, 419-874-2393. The website I hit says he’s 75 years old. Is he still active? Well, I’m still farming at 71!