The 442 has all drum brakes. The Fall weather is nice and started to drive it more since being in hibernation mostly for 2 years. Drove it to work 4 times over 2 weeks and on the 5th time all of the sudden the brakes are weak and bad enough not safe to drive now. When I press on the bakes, I hear a "swoosh" and the pedal goes down far enough where the brake light goes on too. I checked the master cylinder and the reservoir closer to the windshield was full. The other one was only 10%full. I went to Autozone and filled it up and drove home. It did the same thing and no improvement. Today, I checked the reservoir and both are still full. Any ideas. what could it be ? And adjustment? I thought if a wheel cylinder bust that that I would have lost fluid in the master cylinder?

On a side note, I never was thrilled with the braking performance on the 442. It has all drums compared to my Delmont which has front discs. The Delmont brakes like a new car, the 442 was slow to stop but I always had a hard pedal until today. I had my mechanic look at the brakes a few years ago (and the pedal was still strong then) and he sad the shoes had plenty of meat and the brakes looked fine to him.so I left it alone. I was too cheap then to convert to disc brakes.

So two things, what do you think it is for a quick fix? I may also ask the shop to convert the front to disc brakes. If so, is there a recommended brank or set? It runs great but the stopping performance had always been unsatisfactory, now unsafe.

 

The front reservoir feeds the front brakes. Look for a leak at the wheel cylinders there. Be sure to peel back the rubber boots on the ends of the cylinders and check for wetness. If they are dry, you need a new M/C. And if the BRAKE light came on, you likely need to bleed the system at a minimum.

 

Thank you Joe. Dumb question, if I had someone convert to front disc brakes does that usually come with the wheel cylinders? I have all drum brakes now. I am thinking of two things : 1) A cheap fix in case my mechanic is busy and 2) and front drum conversion because I was never happy with the braking performance even when I had a stiff pedal. My mechanic checked it out a couple of years ago and said that everything looked fine, but it never brakes like my Delmont which has front disc brakes. I wind up not driving the 442 because of poor braking. I am afraid to mess with anything stock though. Kind of scared of the conversion.

 

I'm not sure what you mean by the "wheel cylinders". Disc brakes have calipers, drum brakes have wheel cylinders.

 

Oh okay good to know Joe. I was wondering if I converted to disc brakes if I would still need to repair the wheel cylinders (I have drum brakes in the front). Looks like if I converted, would just throw out the old drum wheel cylinders. My Delmont has front disck brakes and brakes like a new car. The 442 has all drums and brakes awful. I have to drive like a grandma in the 442 even though I have all that power. Live in the City.

 

There's a thread around here on how to convert to disc brakes using stock components, which is better than doing the "disc conversion" bullshit that scarebird and others offer. You will need, at a minimum: disc spindles, rotors, hubs, lines, master cylinder, and you have to choose how to address the proportioning issue as well as what generation Olds disc brakes you want. The stock 67 system used fixed calipers with 4 pistons and different rear cylinders that handled the proportioning right, and just a metering valve. Later years used normal cylinders in the back, and a proportioning valve and floating, single piston calipers. Either system is fine, just make sure you are doing one or the other and not some of both. This is not something a normal mechanic would do for you; you'd need a restoration place and to source parts.

Oddly enough, my 67 442 brakes like a champ with 4 wheel drums but I did a complete brake job on it years ago. It's odd because it takes off like crap, looks like crap, but, boy, can it stop. Drums work great initially, if yours don't work great initially, there's something wrong. But, cold brakes, that first hit should be very good. Fade happens, but that's something else.

You've blown one of the front cylinders, I bet. Most of the braking comes from the front.

 

Thank you Koda for your post. You got me thinking. First I didn't know that Old had disc brakes in 67 - I thought all along that started in 68, but appears I was very mistaken. Looks like disc brakes have been around much longer. In your post, when you talk about the "rear cylinders", are you referring to the rear cylinders for the rear-drum brakes. Little confused why we are talking about the rear when converting the front. I am pretty dumb with this - it appears that you just cant slap discs up front because it has to work to some designed proportion, correct?

To circle back, I bought the car in 2016. The braking was unsatisfactory when I bought it, but good enough to buy it because everything else was great.. I took it to my mechanic who knows classic cars, and he said that everything looked fine. There was around 60% of meat left and he made adjustments I think to the shoes. I think he bled the brakes but not sure.. The pedal remained stiff but the braking capability was still not great. I did not notice much improvement. It would not stop on a dime at all but it was good enough to drive around town slowly like a grandma. I grinned and beared it because I looked at it more than I drove it. You got my thinking too about what you said with your drum brakes! In addition to any leaking wheel cylinders, maybe I just need new drums and shoes in the front, or maybe all 4! You are right something must be wrong from the get-go..

I remember when I drove my Dad's 1969 GMC Truck in the 90s. It all all drum brakes and I remember it drove and braked fine. Something about my drums were never right. Even when I had pedal, it would never jolt stop when hitting the brakes, it was like a gradual stopping. That maybe why I busted a cylinder recently. The wife is complaining that I don't drive the 442 and it is just gonna rust away. Now that I have been driving it, I probably pressed on the brakes harder than I had to to stop because it is not stopping well. I think I am getting talked into getting new drums and shoes. If I do that is there any brand you all recommend? Maybe I don't need new disc conversion afterall.

 

Because maintaining the correct front-to-rear brake balance is necessary to avoid premature rear wheel lockup and potential loss of control. For the 1967-70 cars, Olds did not use a proportioning valve with disc brakes. The rear wheel cylinders were actually made SMALLER on disc brake cars to properly balance the front/rear bias for a given line pressure. There's more to converting than just bolting on a kit. Frankly, most aftermarket disc brake providers are completely clueless as to how to properly design a braking system. For example, these vendors all use the same Chinesium one-size-fits-all combo valve. The factory used a wide variety of combo valves for specific applications depending on the weight of the vehicle and the front/rear distribution.

 

Thank you Joe, I needed to understand the engineering on that and you explained it well. By the way, on disc brake cars, what does decreasing the size of the rear wheel cylinders, which have drums/shoes, do? I know if affects the proportion, but would a smaller rear wheel cylinder decrease the braking force from the same pedal movement or is it more complicated? I don't need to know that, but I was curious as to the mechanics. I am assuming when we are talking about "proportion" we are talking about when I press on the pedal, X% of Force goes to the Front brakes and Y% Force goes to the rear. If I decrease the rear cylinder size, I would think we now have something like 1.1 X% Front Force and 0.9Y% Rear Force (meaning decreasing the brake force of the rear drums) because the front discs are doing more work.and if the front discs are doing more work, we need the rear to do less work?

I am getting more and more convinced that I should just get a new drum brake brake job.

 

Ok the reason is that reducing the cylinder size proportionally reduces the rear braking force from the same pedal movement. It takes more pedal to get discs going than drums, so you either have to reduce the cylinder size in the back, or put a valve in to reduce the force, otherwise your rear end is coming around in a panic stop.

The takeaway: if you go to discs, use stock components all from the same year's design.

Yes, go get your drums fully functional, then see if you like it. You should like it just fine.

 

Thanks Koda, if I am going to replace the front, I mine as well replace all 4 I am thinking. The parts for drums don't look expensive at all. Rock Auto has drums from ACDelco and ones from "Dynamic Friction". Anyone have any brands that are proven or should just trust the mechanic?

 

And to expand on this just a little, drum brakes are self-energizing, which means that once the shoe engages with the drum, the motion of the drum turning forces the shoe into the drum even harder. Disc brakes are not self-energizing, which means that they typically need higher line pressures. This is why GM was reluctant to offer manual disc brake cars for quite a while until the mid-year 1969 W30s. Higher line pressure to the front disc brakes means the same higher line pressure to the rear drum brakes, causing them to lock up prematurely. On newer cars the proportioning valve reduces the line pressure to the rear, but on those early cars Olds simply reduced the diameter of the pistons in the wheel cylinders. Less area means less force at a given pressure, or conversely the same force at a higher pressure.

Once again, there is a lot more to properly engineering a brake system than bolting on parts that may or may not be matched.

 

Just a note if the pedal is just as stiff with the engine running compared to with it off, you have a bad power booster. The brakes should not be scary even with drums, my guess is there are problems and leaks that need attending to.

 

^^^this.

 

Thank you gentlemen. For clarification, in the last two days I get a squeeshie noise and the pedal goes far down especially when one so now I believe yes I have a busted wheel cylinder.

Before a couple of days ago I had a stiff pedal while driving and while off, and although I had a stiff pedal the car would not slow down well while braking. It very well could be the power booster as when the mechanic checked it out around 4 years ago, he said that all drums looked good. I believe the rear shoes looked almost new and the front had 60% meat on them if I recall. He drove and he thought the braking was fine but I knew it was not right. When you go around 10 miles per hour and pressed hard on the brakes, it should feel like it is going to skid and if never felt like that - it would just go to a slower crawl. The only thing I can think of he overlooked the power booster because it looks new. Everything under the hood looks like it was replaced when the new rebuilt 425 was installed before I got it.

Having that said, let's say it was the power boaster. What else can one do to test the functionality of it? To put things in perspective, I think my 68 Delmont has the original power boaster or at least the same one from the last 30+ years and works great. The power boaster I have in the 442 is probably around 6 years old, but has less than 1,000 miles on it.

I appreciate you all bringing this up as I could replace all the drums and still have the same problem. uh!

 

You have 2 problems as I stated previously. You have a leaking wheel cylinder/s, and probably a bad power booster. You need to do an inspection of your brake system and repair what's bad. I assure you that your stock brakes when working correctly will stop your car very well.

 

I used to have a 58 olds years ago that was my daily driver for 4 years with drum brakes all around. I rebuilt the whole brake system from power booster to wheel cylinders, all brake lines and all new hardware return springs etc. The car stopped like brand new and never gave me trouble

 

I'll add that my 1962 F85 wagon has rebuilt factory four wheel manual drums. The one change I made was to swap from the original 1" bore M/C to a 7/8" bore dual circuit M/C. The difference in stopping power is quite noticeable. I drive this car a lot, and have never had a braking issue. On Hot Rod Power Tour in 2019 the route included a very winding stretch of US 58 through the mountains in southern VA. The brakes worked fine with no issues.

 

Btw. The condition of your brakes from four years ago has no relevance to the condition now. Even if you didn't drive it much. Wheel cylinders could be leaking, Brake hoses could collapse. Steel brake lines could develop pinhole leaks. Booster diaphragm could have ripped. Take it in and have someone you trust look at it. A 67 442 with drums should stop reasonably well with drums.

 

Totally agree, go through the whole system and I'm sure those brakes will work pretty good. Then you can assess if you want to change it over but I think you will be more than satisfied

 

Also sometimes a mechanic will tell you it looks OK, because he doesn't want to work on an old car with limited parts availability. If he can't get the parts it just takes up space in his shop without producing revenue.

 

There is nothing on a 67's brake system that is limited or you can't get through a local auto parts store.

 

As an update, I hope to bring it to the shop next week for evaluation. I already communicated to the shop about updates from this board and thank you. One thing I learned from this board is the power booster may not be working as good as it looks.

The mechanic's inspection from 3-4 years ago is semi-useful, not totally irrelevant. Although anytime you have an old car, one needs to new check for evaluation, I was communicating this history not so much to fix the recent squeeshiness and soft pedal, which is probably a wheel cylinder or maybe something else too, but I wanted to share that if it is the wheel cylinder to fix the soft pedeal, most likely there is some of other issue that is preventing the car from great braking performance because before the recent squeeshiness, the car braked the same the last 3 years and although it was not squeeshy and stiff pedal, it was unsatisfactory braking and the mechanic did not notice anything obvious. He made obvious adjustments and I believe bleeding. And although the car was okay for sporadic driving, it was not fun to drive as the braking was not were it should be. I was okay with it because as I did not drive it much and had other things going on..

The mechanic could fix the squeeshiness and get the firm pedal back, and perhaps get it to where it was before a week ago, but that is still not acceptable to me and hoping he can improve it to where the braking performance should be.

In any event, a new evaluation is necessary and a mechanic is probably never going to make repairs based on a 3 - year old inspection - totally agree. But the prior inspection does help with new clues as to what could make it better such as the power booster. Will see. I wanted to make improvements on the braking even before the recent squeeshiness, this just put me over the edge. Probably not explaining this well but already wrote too much. lol

 

I agree sometimes mechanics will say they know how to do it when they really don't that's when you're better off doing it yourself if you can At the end of the day go through the whole system get it right and I'm sure you'll be happy with those 4 wheel drums

 

I recently experienced that. Brakes worked fine last year, parked the car for the summer hibernation, then when I rolled it out in the fall the brakes were soft due to a leaking master cylinder. I am amazed that it went bad while sitting idle in the garage.

 

The best thing to do is if you don't drive the car because of the weather start the car up every couple weeks let it at least idle with the garage door open and pump the brake paddle and keep everything moving and lubricated it does help. My cousin lives in New York and that's what he does with his 67 Chevelle

 

Hi Fun71, good to know. What happened to me was not exactly happened to you. I started the car at least every 2 to 3 weeks to no less than operating temperature and pump the brakes. I also drove the car to work and back (around 20 miles round trip) 4 times in the last 3 weeks with no change in performance from the last 3 years. 1/3 of trip going over 60 mph. It braked like it always had. Up until this time, it was braking good enough but not great like it should. No squeeshiness, hard pedal, but not quick stopping. On the 5th time, got the squeeshiness where the brake goes close to the floor and now dangerous to drive.

3 years ago, the mechanic inspected the shoes and said I had around 60% meat on the front and the back looked new and did a test drive (he was okay with performance then but I was not but it was good enough to move on then). Since 3 years ago, I drove the car maybe 300 miles so the meat is probably the same. So what would makes sense is that the power booster was semi-bad before and now really bad or the power booster was bad before (still is bad) and now busted a wheel cylinder. One of those two would make logical sense. Assuming that the drums and shoes still look good.

 

Hey Griffey, I do what your cousin does. I learned a valuable lesson from Dad. The Delmont was my Dad's until 2012. Before I got, he let the car sit in the garage for a couple years with doing nothing and what happened was the calipers froze (big deal) and the fuel gauge stuck on 1/4 tank (minor deal but annoying). Before my Dad gave me the car, he had a mechanic rebuild the calipers to working condition. These brakes are not meant to not be used for long periods of time. And back then there were no replacement calipers for the Delmont, it was big deal to have the mechanic fix them on that car. Your cousin is quite smart. At least once a month I backup into the driveway and brake forward and backward.

 

It's like exercising your car And it works keep everything going

 

Reading this made me remember that my brakes were similar to that before I found the master cylinder leaking. They worked OK but I couldn’t lock the wheels up when standing on the brake pedal. After replacing the master cylinder, I can lock them up as you would expect when braking hard.

 

Thank you Fun. That does not make sense. When I got the squeeshiness a couple of days ago, the front reservoir was only 10% full. It was not total empty. I filled it up but made no difference. Don't know if this makes a difference but I never see any brake fluid in the garage so don't know where it is leaking too if leaking unless it is internal. I would not be surprised if the master cylinder needs to be replaced regardless if any wheel cylinder needs replacing too. It looks newish but I know that does not mean much. I have a feeling the car was not driven by the previous owner as well.

When one presses on the brakes pretty hard going like 10 mph, the car should jolt-stop short. The car never did it since I owned it even before the recent squeeshiness.

 

You need to go through the whole brake system master cylinder all wheel cylinders all brake lines brake shoes and then you should have a perfectly good working break system

 

By the way, there is one more bit of information, not sure if it matters. When I pulled the cap off the master cylinder, I mentioned that the front reservoir was 10% full, which I filled that day. But also the rubber cup that is normally positioned in that reservoir was no longer protruding outward, it was instead stuck depressed inward. I pulled it back out before I put the cap back on, but I can tell that it was flimsy not like the other rubber cap that goes over the reservoir closer to the windshield which was firmly outward and in better shape. Thought I mention this as it appears this rubber cup is more important than I thought .

 

That rubber part in the lid is supposed to “balloon” and fill the space as the fluid level drops.

As for the missing fluid, there’s a leak somewhere. It could be the same as my master cylinder and is leaking into the brake booster. I had that happen before back in the 90s, so on this recent issue I knew what to look for. I unbolted the master cylinder from the booster and sure enough, it was damp.

 

If your fluid is low (only 10%) and it's not leaking at the wheel cylinders and no stains on the floor, Then it's being pulled through the power booster. You need to replace the power booster and also your master cylinder.

Now that you've added the fact, that the mechanic has said that they were good because they had 60% brake linings left. That implies he did not look at the hydraulic system. I would suggest that after he replaces the booster and master, if the wheel cylinders are good you have them inspect ALL your steel brake lines (for brake fluid dampness) to identify any rusted out lines (a failure in these with a single reservoir master will lead to total brake failure and likely a crash). Also I would replace all 3 rubber brake hoses, these can also fail and could be over 50 years old and they deteriorate internally so visual inspection is useless.

 

If the FRONT reservoir is low, it is not being sucked past the back reservoir into the booster. The more likely failure mode is that the M/C internal seals are worn, causing fluid to flow from the front to the rear reservoir. I've had this happen to me before. In any case, it's trivially easy to check for leaks at the back of the M/C before spending a dime on a new booster. Simply unbolt the M/C from the booster and pull it forward enough to check for wetness at the rear of the M/C. There is enough "give" in the lines to do this.

 

Some new information: It looks like the car had a rotisserie renovation before I bought it ( 5 years ago) and has been garaged kept since with few miles so everything looks new from the outside. All shiny metal and no corrosion. The MC and booster, master cylinder metal hoses, and brake lines look new ( There are not new as I had it for 5 years - just saying that it looks new from the naked eye). I was not fully clear as to the condition in prior posts. I understand though that does not mean it is working internally properly - just no obvious rusting hoses. Unlike the Delmont which is 80% original under the hood and has some rusting and dirty, the 442 was all redone and shiny new looking all over.

I agree with sysmg and other posters who thought that the mechanic did not test the hydraulics just looked for leaks and shoe wear and did a quick test drive. That is why I asked the question earlier, how can you test the MC and booster effectiveness? The only thing I can think of based on looking at other posts is to do a test drive. The pedal was firm and braked okay when I bought it and during the mechanic test, but not great like it should. The mechanic probably either thought it really was okay or didn't want to freak me out to spend more money and replacing the MC because the MC issue is subjective whereas shoe wear is objective (my opinion unless I hear different). My hunch is because it looks new he thought it could not be that or really disagreed with me with my opinion the brakes were not that great. He told me it braked like it thought it should but it did not to me absolutely. I could have pressed him like some other issues I had with my Truck and took a test drive WITH him then, but didn't. I thought about that many of times but like I said it was not big of a deal then and was happy then to not spend more money after buying it. I will this time if have too.

Based on the posts, if there are no leaks and squishy pedal, the only way to tell the booster/ MC is bad is from opinion on the braking effectiveness from a test drive. I was hoping there was some instrument to test - that it what I was hoping to read.

An update of the reservoir, the front was 10% full after initial inspection a few days ago after the squishiness appeared, but I filled it that day and drove it home. I checked it this morning and it is still full, but the brakes still have the squishiness. I would have thought the front reservoir would have went back to 10% full again but it is not all full still.

After inspection today, I did not see any obvious leaks where the MC connects to the power booster, but will check again. I think the some fluid is there from where I spilled some while re-adding.

Joe - I may disconnect the MC from the power booster if I don't hear back from my mechanic soon as to when I can bring it in. Thank you - great posts!

 

No matter what brakes are the most important thing on any car spend the money there 1st always everything else can wait you always need to stop