Power Brakes for a 1960 Pontiac StarChief

Hello, I am restoring a 1960 Pontiac StarChief, 4dr no post (Vista) model, 8cylinder 389 engine. This vehilce has 4 wheel drums, no disk brakes in those years. My question is regarding the power brakes. When I stop, I have to make a huge effort to push on the brake pedal. I know I am stopping a 4,000 lb vehilce, but something tells me is should not be this hard. This is what I have done so far, replaced all brake shoes & adjusted to factory specs, had drums turned, rebuilt brake cylinders, replaced rubber brake hoses, replaced vaccume hose from coffee can thing in drivers fender to brake booster, changed brake fluid, cleaned out master cylinder. The only thing that I have not done/looked into is the power booster. How do I rebuild this or should I have to? What is the purpose of the p. booster?

Thank you very much.

Kind Regards,

Todd Koger, Columbus Ohio 614-582-9384

PS…No one is old enough to remeber how these brakes are suppose to act, including myself. Or am I spoiled by my 89 Eldorado 4 wheel disk brakes?

Very little effort is required to operate these brakes. The vacuum booster is probably shot. It is what supplies most of the braking effort…A similar system is still used today…

I’ll take it a little further than Caddyman: power brakes of that era usually required less pedal effort than cars of today. You were supposed to keep your heel on the floor and use your toes to press the brakes. Not much effort required. Of course, the drum brakes still sucked, but you could lock them all up using just your toes.

I agree that the power booster is probably shot. But before you replace it check to make sure it has manifold vacuum at the large hose feeding the booster, that’s probably shot too.

Thank you for your reply. So, can I rebuild the P.Booster myself? Where do I go for parts or a kit? Can you please explain further on the manifold vaccum? There should be vaccume from the coffee can thing to the booster?
Thank you again.
Todd K. Columbus Ohio

I’ve never heard of anyone rebuilding a power brake booster. I don’t know if a rebuild kit has ever existed.

Power brake boosters usually operate on vacuum. Typically, there is a large (1/2" to 5/8" outer diameter) hose connecting the brake booster to the intake manifold. This supplies manifold vacuum to the power booster when the engine is running. Additionally, at the booster end of the hose, where the hose enters the booster, is a one-way valve. This will keep the vacuum from bleeding away and leaving you without power assist if the engine stalls.

It should not take much pressure on the brake petal at all if the power brakes are working. Something is amiss. Check all the vacuum hoses, remove and replace with new if possible. A hose could be collapsing, or could be clogged with debris.

I haven’t ever had to rebuild a power brake booster, they fail infrequently. They are full of rubber and various seals inside so something could have simply rotted out internally over time. I would try to find a new part. You should get hooked into some old car restoration forums and find parts sources for historic cars like yours.

A new booster and new vacuum lines and you’ll be stopping on a dime. Drum brakes are powerful. They don’t do well when they get wet, so stay away from forging streams. They can fade on long downhill runs in the mountains so you learn to step on the brakes to slow down and release them to let them cool when going down a mountain. Petal pressure shouldn’t be an issue at all once you get them working properly.

My grandfather had a 1960 Bonniville. It was very fast and powerful. The power steering was so light touch that it was a challenge to put your hands on the wheel without an steering imput. In other words it was hard just to go straight down the thruway. The power brakes also had a very light touch. A little pressure had passangers pitching forward in the seats. A very powerful car with light steering and brakes was a challenging car to drive smoothly.

The power brake booster is probably leaking. Make sure the vacuum hose is running directly off of the manifold. Once the vacuum is verified connect it to the brake booster and listen for leaks. I don’t know of any way to repair a leaking brake booster so you need to try to find one. The 389 engine is nearly bulletproof. I had a 389 that went through 3 vehicles. I kept finding better bodies to put the engine in. It started out in a 60’ Bonneville then to a Catalina and then on to a nicer convertible Catalina where it stayed.

The equipment needed to seperate and reattach the shell of a brake booster is not commonly found in even the most well equipped shops. If you confirm that vacuum is properly connected yet the pedal remains high and hard a rebuilt booster is in order.

Like everyone else, I never heard of anyone rebuilding a power brake booster, from an older car to a newer car or anything. I believe the two halves of the booster are either welded together or crimped together, which would make a rather ugly chore of disassemblying one. you should be able to test it with a common hand held vacuum pump, similar to how you test other vacuum operated valves and motors. It will just take more pumping. But with the internet and my friend Google, I’m betting you can find one out there at a reasonable cost.

Yes, you are probably spoiled by the disc brakes on your current ride. I had the same problem when I first bought a 65 Chevelle that had the 4 drums on it. Required a lot more effort than I was used to to stop the car compared to the Civic I had at the time(still have it too, just sold the Chevelle a couple years ago)

I am old enough to remember the brakes of that era. Drum brakes without power assist felt a lot like todays power disc brakes. With a power booster, the brakes were very touchy, a lot of people didn’t like them. However, if the power brake booster lost its vacuum, the brakes required a lot more effort than the non power brake versions.

Power steering of the era was also touchy, but the steering ratios were so high that it still took a few turns of the wheel to get around a corner. It was called hand over hand steering so while it was very light, a sudden small movement of the steering wheel seldom translated into much lateral movement of the vehicle. 3.5 turns lock to lock was normal for power steering, 4.5 to 5 turns for manual steering. Today, 1.75 lock to lock seems pretty common. I can’t remember turning my steering wheel even a half turn to go around a corner in my present car.

Oh boy oh boy, that sounds like fun. I had a 59 Catalina way back in '69. That would be a hard top that you have if it doesn’t have the post or a sedan if it has the post. Your brake booster is shot. It should take very little effort. Its about a 20 minute job to swap one out. Mine failed by locking down and you’d have to pull it up with your foot.

Now where to get one. For used, you can do a search on car-parts.com. Not sure if they go that old though. A place called French Lake Auto Parts just north of Minneapolis specializes in old cars and they might have one. Google them or it might be FLAP.com. For new or rebuilt, try Rockauto.com. They now carry old car parts but may have to call them instead for help. The same boosters were used for a number of years on the GMs so was a pretty common part.

First, you need to get a GM part number for that booster. THEN you can track one down…This kind of stuff is what makes restoring old cars so much fun…Thank God for the internet…

In researching your power brake unit in a Motor’s Repair Manual, I got some interesting information. Yes the boosters were rebuildable but I don’t know where you would find the parts. When you crank the two halves apart, there is a spring that returns the power diaphragm that has to be restrained or the two halves will fly apart.

The interesting things I learned are that the master cylinder piston is integrated into the power booster unit. The booster has to come apart to release the piston. If you are losing brake fluid without obvious leakage, it could be going into the booster and rotting the diaphragm. This booster runs at atmospheric with vacuum from the canister being applied as needed by the valving. So the booster unit is not under vacuum on both sides of the diaphragm as is now customary. If the diaphragm is leaking, you will hear a ‘hiss’ under the dash when the brake is applied and the engine will probably react with higher and/or rougher idle as long as the pedal is applied. If you can find the diaphragm, the appropriate internal vacuum hose, and the rubber valving parts, you might copy off the Motor’s rebuild pages and try to rebuild yourself.

You might call around to various brake shops and ask who they would recommend for rebuilding the unit. It sounds like the best approach is to find a business that specializes in rebuilding these units. I remember back when I had a problem with a Volvo power boost unit that there was a shop that offered to rebuild the unit if I shipped it too them. Since the 144 was needed for work transportation, I opted for a dealer replacement unit at substantially higher cost but off the shelf availability.

Good luck on this.

Is it ethical/acceptible to mention a brand name here?

Not sure what brands you are talking about or just an open ended question? Pontiac is a brand, Motors, Bendix? At any rate, here’s the relevant rule:

“Feel free to share your ideas and experiences about relevant products or services you’ve discovered. But the Car Talk Community is not a place for advertising, promotion, recruiting, campaigning, lobbying, soliciting or proselytizing. We understand that there can be a fine line between sharing a tip and promoting a product; use your best judgment ? and we will use ours. We also ask that you do not misuse the ratings, ranking or flagging systems.”

First, there is some room for confusion in the power brake system on the Pontiac. I was under the impression that by '59 the vacuum boosters were Moraine diaphram types while earlier models used the integrated master cylinder/booster. None the less, a local parts store carries rebuilt parts branded “A-1 Cardone.” When rare parts are not available the store ships the old part in and gets it rebuilt. This is somewhat time consuming, 10 days +, but the results are always satisfactory. This manufacturer’s products are the first choice here whenever needing rebuils and most parts stores stock some lines of that brand, even the McParts stores. Good luck on the Pontiac Todd… And Chilton’s manual for that model is still available.

…and if the power booster is leaking, it creates an enormous engine vacuum leak, so the engine will probably idle and run better if you get if fixed as well.

Hello All,
After alot of research and digging I did find three places that manuf. rebuild kits for the Power Brake Booster, on in NJ, one in Oregon, and Illinois. All three would rebuild it for me if I sent in my original parts. I choose to do the repair myself, only because I am the kind of guy that like to try it myself first, and then call the pro if I get in trouble (Yes, it does happen :slight_smile: If you would like more info on this shop, post back.

I’ve never rebuilt one of theses things but Researcher’s comment about the internal spring is something that should be kept in mind and you should use caution if doing the job yourself.

Springs on other automotive parts (struts for example) and even old antique motorcycle parts such as springer front forks or the old Triumph sprung hubs (with springs inside the rear wheel hub) can be extremely hazardous to your health or even fatal.