1958 Buick Century Brakes Renovation

[Chcknugget]

Hello!!!  I am fixing up a 1958 Buick that was purchased by my grandfather in the 70s but has been sitting in a barn for 30 years...  I have the engine tuned up and running well, so now I am tackling the brakes.  I have all the drums off and I am wanting to replace all hardware, shoes, lines, hoses, and get the master cylinder rebuilt.  I'm hoping to possibly cruise this summer!

 

2 questions:  Do I have a Bendix master cylinder?  Should I assume my vacuum booster needs to be repaired as well?

 

Thanks, Colin

 

 

[buick man]

… Colin great to hear you are doing this … it appears you have a Moraine unit and not a Bendix unit.  Very , very similar with some basic few internal differences though enough however that the kit for the Bendix you find on flee bay will be the incorrect one … so advise you find that specific one.  Make sure you first obtain a 1957 or 58 Buick authentic shop manual and read the very detailed portions regarding the operation and rebuild of your unit.  Also, do not be hood winked into believing the master cylinder needs to be "bored n lined".  The only boring that will be done, will occur in the vicinity of your wallet … read up on the operation of the M.C. and you will discover this is true and that the unit operates and forces fluid throughout the system by a form of negative displacement and there is therefore no need to bore and sleeve the m.c. . Do a search on this forum and see what you come up with and report back and let us know …. oh btw: we are anticipating that you may not fully envision how to most efficiently go about removing the entire unit with the least amount of pain and suffering so here is a photo of our complete unit removed … this is a Moraine unit … please note the required precise instruments being used at their strategic attachment points …. yes one has to "spin" or turn the unit in the engine bay to get the unit out while at the same time under the dash that wide round mouth vise is holding onto the large almost inaccessible large nut hidden just above the brake pedal perch and cluster … thus the photo you see before you ...

 

 

 

[Bhigdog]

If you decide to just send the unit off for a rebuild I can't recommend you send it to Florida. If you are replacing all the hardware you should consider using DOT 5 fluid. There's a ton of stuff both pro and con here on the forum on that subject.............Bob

[D Yaros]

I had to have the brake booster on my Oldsmobile rebuilt.  I used this outfit and was very pleased in terms of a) communication, -b)- quality of work, c) turn around time and d) price.

 

http://brakematerialsandparts.webs.com/boosterrebuilding.htm

Edited January 27, 2017 by D Yaros (see edit history)

[Pete Phillips]

"Buick man" didn't mention the contortions you have to go through in order to apply said round mouth vice grips onto said nut high up on the inside of the firewall underneath the dash. Unless you are under 150 pounds and under age 40 or so, it is sometimes easier to remove the entire front seat to get the appropriate angle and access to said nut, if you can believe that.

Pete Phillips, BCA #7338

[NTX5467]

On MANY under-dash labor operations, it can be much easier to remove the front seat rather than hang your legs over the backrest of the seat, with your shoulders on the floorpan, to do work.  It might sound crazy to remove the seat, but when that nut was installed at the factory, the seats were probably NOT in the car.  All things considered, it might be good to put some thick towels or a shop blanket where you'll be laying.  This can also serve as "a catcher" for anything which might get loose.

 

While you're under there . . . look around for any cables for the heater controls that might need some attention/lube, too.  Might be a good time to lube the speedo cable, too? 

 

NTX5467

[g-g-g0]

1 hour ago, Pete Phillips said:

"Buick man" didn't mention the contortions you have to go through in order to apply said round mouth vice grips onto said nut high up on the inside of the firewall underneath the dash. Unless you are under 150 pounds and under age 40 or so, it is sometimes easier to remove the entire front seat to get the appropriate angle and access to said nut, if you can believe that.

Pete Phillips, BCA #7338

 

Just think what it was like for a 6' 76 year old 230# individual with tons of arthritis from three back surgeries! A genuine pain in the A**!

[Bhigdog]

What worked for me, after trying every wrench I could think of, was to tap the nut loose with a long chisel. Once it was loosened it came off easily. Thanks to the booster rebuilder in Florida I got pretty good at repeatedly removing and reinstalling it. I finally made a nut with castellations  rather than flats and it was easily tapped tight or loose with a flat bar...................Bob

Edited January 28, 2017 by Bhigdog (see edit history)

[Beemon]

10 hours ago, Bhigdog said:

If you are replacing all the hardware you should consider using DOT 5 fluid.

 

Careful! While DOT5 brake fluid does indeed repell water, it does a really good job at trapping air and is thus harder to bleed. Also if DOT5 brake fluid has touched anything that has previously had DOT3 or 4 brake fluid in it, then seals will fail due to swelling. If you use DOT5, then you need to replace the wheel cylinders and the proportioning block if it has one, as well as the stop light switch and rubber hoses. Looks like you're well on your way to a full brake job, but be warned DOT5 is not to be mixed with DOT3 or 4 at any given time. The two types completely alien to each other and will lead to failure.

[Chcknugget]

Thanks for the help. I'm planning on replacing everything... Inline tube is only a few miles from my house after all!  I'd prefer to spend the money and send out my master cylinder for a rebuild but sometimes it can be less aggravating to do it yourself.  Not sure what I'll do yet.  Luckily my floor is pretty rusted out so I can probably grip the nut through the bottom of the vehicle!

[NTX5467]

Has the composition of Dot5 fluid changed from the original "silicone" fluid? Reason I ask is that when it came out in the middle 1970s, or was discovered by "car people", as it had already been in use in motorcycles at that time (the motorcycle shops had it in stock), none of these bad things were mentioned.  The silicone fluid and Dot3 would be "stacked", but they'd eventually separate, but caused no operational issues (back then).  Other than not attracting moisture, the main issue was non-damage to painted surfaces.

 

I had a friend who put it in his 1979 Corvette (as the Corvette 4-piston calipers were known maintenance/durability problems) with no problems, short or long term. He did mention that it took some extra time to bleed the brakes, with the pedal "getting harder" after about a week or so of driving (which could correspond to Beemon's comment about it being harder to get the air out).  He had the car for several years after that.

 

It's my understanding that Dot4 fluid is Dot3 with a higher boiling point?  The last-gen GTO spec'd Dot4, rather than Dot3.  Seems that there's no real reason to use Dot4 over Dot3 in normal vehicles.  Prior to the Dow-Corning silicone brake fluid, Castrol GT LMA fluid was supposed to be the best as to lowered moisture attraction (Low Moisture Avidity).

 

So, what's changed from the old Dow-Corning silicone brake fluid and the current Dot5 brake fluid?

 

Just curious . . .

NTX5467

 

[buick man]

… nugget … don't let these well intentioned bunch frighten you as I sometimes too get stiff just listening to em  … the method we subscribe to as stated above,  just requires you to open the driver's side door and kneel down and take the clevis pin and cotter key out from the brake bracket next to the steering column and if you can still bend your elbows then no problem, then open the passenger's side and simply crawl in and lay down on your left side/back over the floor board and attach the pictured wide mouthed grips as shown, it fits right up in there easily and efficiently as the firewall bracket metal is not an obstacle which by any other approach, makes any other attempt to take the nut off a ball buster ... and no cave man banging in required …. I'm around 185 lbs and have had no problems with this so unless your waistline matches your I.Q. then you should have no problems ...

[NTX5467]

(One hour later)

 

The reason my friend did the change to Dot5 silicone fluid was performance-based plus the known issues of expensive brake caliper rebuilds from normal moisture issues of Dot3 brake fluid.  He had good results with it.  Be that as it may.  At that time, the Castrol GT LMA brake fluid was about as good as it got.

 

In doing research, some things have changed.  There can also be some differing orientations!

 

One thing which changed is the availability of Dot5.1 fluid.  Dot3 is a glycol based fluid.  Dot 4 is a glycol based fluid with a borate additive and a higher boiling point.  Dot5.1 is a glycol based fluid with the same performance specs as Dot5 silicone brake fluid.

 

The federal FMVSS specs state that Dot5 silicone fluid meet the same compatibility specs as Dot3-Dot4-Dot5.1 brake fluid.  Seals and all.  Mr. Adler at the older GM trucks place has some better specifics on that in his article (www.adlersantiqueautos.com/articles/brakes1.html) where he mentions the designed mechanical interference fit of the cylinder cups and the designed-in expansion of such cups by glycol based brake fluid.

 

A FEW other things were mentioned, too!  One is that should a master cylinder leak into the vacuum area of a vacuum brake booster, then be introduced into the engine's intake manifold (the engine), when silicone burns, it quickly becomes "sand" and we know what that can do to the insides of an engine.  Glycol based fluids burn "harmlessly".  The OTHER thing is that although silicone brake fluid is much less damaging to a cured paint surface, should the silicone fluid be dripped onto the shop floor or anywhere else inside of the enclosure, at any later date when that "spot" is disturbed, silicone components can return to the ambient air.  Should any paint work be being done, "fisheyes" can develop!  Even years later.

 

Mixing?  Generally recommended against.

 

As for the "pedal feel" with Dot5 silicone fluid . . . the fact the silicone fluid seems to "bubble" from internal air in it, this can result in a spongy brake pedal feel.

 

Dot5 silicone brake fluid had an earlier unique application on military vehicles. Vehicles which can sit unused for many years, but when they are needed, they must reliably perform flawlessly. The lack of moisture attraction (and related internal corrosion of brake components) is a distinct advantage in that case.  Many "antique" vehicles can be similar, as to extended non-use periods.  It was also claimed that the "spongy pedal" situation made Dot5 silicone brake fluid non-useable in ABS brake systems!  Plus most racing situations, too!  I suspect the Dot5.1 glycol based brake fluid might have been designed for any higher performance operation where consistent brake pedal feel was absolutely necessary, all the time, as it has the same viscosity and boiling point specs as the Dot5 silicone brake fluid.

 

In general, the fluid characteristics of Dot5 silicone fluid can be "iffy" as to its long term use in vehicles not designed for it.  It's best done on a NEW system where all components are replaced AND the rubber seals are compatible with it (one OEM supplier noted their parts were OEM-spec, yet another one said theirs worked with Dot5 silicone fluid).  A flush of an existing system is typically not recommended.  The vehicle paint issues CAN be a "plus" for Dot5, but the "via booster" possible introduction into the engine can be ONE BIG FLAG to that whole situation, to me.

 

And THAT puts me back to the small cans of Castrol GT LMA fluid I've used for the past 50 years, or similar.  Remember when all of the brake fluid cans at the service station were "gallons" and had the "bulb" loosely laying in the open can, ready for use (at least in our more temperate and dry North TX climate)?

 

NTX5467

[Beemon]

Thanks for the write up Willis, meant to clarify later but just got off work...

 

I guess you wouldn't have to worry about the vacuum booster if you had manual brakes.