Well I just installed new shoes, master cyl. wheel cyls. bled the brakes and pedal was firm. Today I tryed the car in my driveway and the pedal got spongy and went down to about 2 in from the floor. Any thoughts,,Oh I almost forgot, I dont have a power booster, just a master
Does your car have hydraulic brake hoses?
I put on new hoses
To be clear: your 57 does not have the original remote hydrovac brake unit? IN OTHER WORDS, HAS someone removed the remote-mounted original 1957 ONLY, power assist unit?
Yes, I got it like this
So if I end up needing a booster, is there better way to go than the hydrovac, I hear they are not the best. Has anyone upgraded to a booster that is easy to install and functions good
What kind of master cylinder do you have now? Single system or dual? I don't know how you'd even begin to use a 58 master without the accompanying booster, so guessing there would be a similar issue with 57.
Some masters are very difficult to fully bleed....are you sure you got all the air out?
The master is single feed 1957 original rebiult and sleeved,,no booster
OK now after driving around only about 1/4 mile, the pedal when I apply is going to the floor so we adjusted the shoes again, no difference. Should I buy a booster? Is that my problem here?
Sounds to me like the master cylinder is bad or you still have (or have gotten) air in the system. Have you checked the fluid level in the master and checked carefully for leaks that could have drained the master's fluid out?
Yes I checked the resevour and its full, no leaks. I just want to know,,,,can I run this car with no booster and the brakes will function ok or,,,do I need a booster
Hello Johnny,
Whether your car has a power brake booster or no booster, the brake pedal should not go to the floor upon brake application. So, I don't think the problem with your car is the lack of a booster. You should be able to drive your car without a booster, but I think you do have some other problem with your brakes.
A master cylinder can be defective without leaking externally. When you rebuilt the brakes, did you re-install the star adjusters from whence they came? Did you have a helper when bleeding the brakes? Which wheel was bled first? You may want to review each step of your brake rebuild, and compare the procedure to that in the shop manual to determine if and where a problem may have been overlooked.
Respectfully submitted,
Christopher Winter
Thanks,,, I installed the old adjusters, I dont know what to do now, Im really lost, as far as bleeding we started with the right rear, then left rear, then right front, then left front. So are you saying that a 57 cadillac should brake ok with no booster?
The booster will greatly reduce the pressure you need to exert on the brake pedal to stop the car. But cars were built for many years before and after your '57 without boosters. Your stopping distances may be longer and your leg muscles will be stronger (or they better be) but the car should have a firm pedal with or without the booster. I don't know what your problem is but I am still suspect of the master cylinder.
Im starting to think the master too, and I will tell you why. Its rebuilt and we bench bled it and fliud came out strong. Then after installing it I needed to take it out so I thought to bleed it again. When we did I noticed that more air than fluid was coming out and I thought at that time, SOMETHINGS WRONG HERE. Again looking at the manuel, all 57s came with power brakes, so maybe this master wasnt designed to work on its own.
Do you have any pictures of your master you can post?
yes,,,Im thinking right now to take it out and re bleed?
Since you've already bled it twice, had a firm pedal, and then lost it all, my opinion is that it has more of a problem than bleeding for a 3rd time will solve. But, nothing like being sure you have covered the bases thoroughly.
Ok I just took out the master and put it in my vice to check it and it appears fine,,Im Very frustrated, if I put it back in should I bleed the system again? thanks for your help by the way
You will probably have to bleed the system again, although you can try it without bleeding if the master is bled and no fluid has come out of the lines where they connect to the master. Figure on having to bleed the brakes again.
If this whole scenario happens again, talk to the overhauler and be prepared to send it back. If the overhauler was you, take it apart and find the bad seal.
Hello Johnny,
I may be misinterpreting your post, but when you bench bled the master cylinder and you said that "fluid came out strong", was the fluid from the outlet port of the master cylinder routed back into the master cylinder, or into a container with the end of the bleed tube constantly submerged? If you bled the master cylinder, and fluid just spurted out of the outlet port (albeit strongly), then you most likely still have air in the master cylinder.
I generally bleed the longest brake line first. This may or may not be the wheel furthest from the master cylinder. It depends on the location of the brake line junction block at the rear axle. I know that for models of the '60s, the adjusters are side specific. So it is not just a matter of reusing the old adjusters, but putting them back on the side of the car from whence they came. I am not sure about '57.
I would recommend that whenever a master cylinder is removed/replaced, you should bleed the system.
Respectfully submitted,
Christopher Winter
Hi thanks for your help. Yes when I bled it ,,,it just blurded out into a container because on the 57 master it has a filler tube hard to expliain, but I will try. So right now the master is in my garage in a vice. At the top is a hole where the fluid goes into it. I screwed in the fitting and above attached is a hose about 2 ft long that goes to a filler tube. I filled the tube and then at the front of the master is another fitting where the fluid comes out. I pressed the brake leaver and fluid came out into a clear plastic container. PS I just ordered a used booster,,maybe it will work,,,maybe not,,am I frustrated,,,YES,,,anyone out there know this 57 system that I can call for HELP!!!!
The shop manual procedure has you bleed the system at the booster (which sits up high) before moving to the wheel cylinders. It doesn't even have a procedure for bleeding the master (which sits way down low). I am thinking that if you are bleeding the system properly and it still isn't getting all the air out, that once you have a booster on the car and can follow the shop manual procedure, that it will be fine.
It because the master is bled THROUGH the booster. Then the next step is bleeding the hydraulic portion of the booster then on to the cylinders.
He does not have a booster, it was previously removed.
Quote from: 35-709 on October 17, 2016, 01:02:11 PM
He does not have a booster, it was previously removed.
He said he ordered one.
Right, but so far he has not had one. I don't see why the master cannot be bench bled and then installed directly to the brake lines and the rest of the brakes bled as usual --- unless the master itself is faulty.
In his first post he described a firm pedal after replacing everything brake related, but then it went soft and finally to the floor. With no visible leaks in the system and the master still full of fluid what else would it be other than a bad master that is leaking by the piston seal(s).
OK, a complete shot in the dark here.
If you pump the pedal do you get it back to firm again? If, on your car, the master cylinder is below the wheel cylinders the fluid can actually get pushed back by the brake springs pushing on the wheel cylinders into the master requiring one or two pumps of the brake pedal to get the fluid and pressure back to actuate the wheel cylinders. This would not happen with the Treadle-Vac installed since it is higher in the system.
This is why on older cars with hydraulic masters under the floor they sometimes have a residual pressure check valve (not the proportioning valve) that actually keeps a small amount of positive pressure in the system to keep it ready but not enough pressure to actually activate the drum brakes. If the master is on the same level as the wheel cylinders or above, there is not a problem, only if the master is lower. With the car level determine if the master is lower than the wheel cylinders. If pumping the pedal does not return it to firm then this post is probably for naught and we are back to square one.
The residual pressure check valves are readily available and inexpensive, street rod and resto-mod builders use them all the time on old cars when they upgrade but keep the master under the floor.
I keep thinking about this --- my post above is not necessarily to encourage adding residual pressure valves to your system, even if that would fix the problem. I too believe, as others do, that the Treadle-Vac should be put back and the system returned to stock for serviceability and safety.
Unfortunately it's a hydro vac. Last year Cadillac used it and it's gotta be from a 57.
OK I just called the company that rebuilt the master and they are sending a courier out tuesday to pick it up and re-inspect it. Thats great. Hopefully they find a problem,,,I will let you guys know ::) By the by, I just bought a hydro-vac used today. I dont know weather Im gonna use it or not, right now. Id like to see if I can get good brakes without it 1st. The guy I bought it from says he took it out of a 57 and theres fluid inside. Also to answer question above, the car was sitting on jack stands when bled, so the master would have been higher. I had a good pedal at that point. But once the wheels were put on and car was lowered, I started loosing firmness
I didn't have it quite right in my Reply #29, I kept thinking of my '35 which has a modern underfloor master and 4 wheel disc brakes. Cars with drum brakes need a residual pressure valve no matter where the master is located because the brake springs will push the fluid back out. The master often has that residual built in but on yours the residual pressure valve may be part of the (sorry) Hydro-Vac, I just don't know. Point is, you should have 2 residual pressure valves in the system, one to the front shoes and one to the rear, if they are incorporated in the Hydro-Vac then you need to add them as long as you don't have the Hydro-Vac installed, they may be in the master which is a good question to ask your rebuilder. Guess I'm tapped out on this one.
Working on the same car in my shop, I took the cover off a new master and used a line from the port right into the reservoir to bleed it, then plugged the port and reinstalled the cover. You might get a pedal when bleeding the brakes but there is no residual valve in that master, hooked directly to the brake system the car barely stops at low speeds and yes it must be pumped to bring the pedal up some.
Reading your post, I was going to say that your problem was the booster. I rebuild and resleaved the master cylinder on my 57' and I had the same problem, and It was the booster. I eventually converted the car to my own dual reservoir master cylinder set up, with a modern booster/master combo. I couldn't afford to get the original booster rebuild or replaced at the time, so I made my own coversion. So now if your just running manual brakes bypassing the stock system, and plan to keep it that may for a while, honestly I would ditch the stock master cyclder find the biggest bore diameter master cylinder for drum brakes and put that in place of the stock one. It would be easy to make up some brackets to put a new master in and mount it on the frame. Heck, might as well just put in a 4 wheel drum brake dual reservoir master in for safety, and for a little better braking performance. The stock master cylinder on this car is painfully small. So it can be bypassed, but I would swap it out with something better if I was going to stay with manual brakes. On the Bendix Hydrovac system on the 57' I think the master cylinder really only actuates a second diaphragm on the booster, and the booster provides a majority of the braking power. I always thought of the master cylinder like a slave cylinder, since all of the magic happens in the booster on this system. The Bendix hydrovac brakes on the 1957 Cadillac is quite a crazy, complicated, misunderstood system.
I did the best and safest job I could do when I had my 57' Sedan before I sold it. But I'm glad it didn't have the hydrovac on it when I sold it. Best of luck with it.
-Gavin
This is how I plan to bleed my master when it comes back. Keep filler tube full at all times. Slowly press in brake rod til all air comes out, then cap it so no air comes in. I will install it with filler tube connected,,,,thoughts?
Hello Johnny,
Keep the filler tube full, and the hose/tube submerged in the jar. Bleed until no air bubbles appear in the jar. If the outlet to the jar is a rubber hose, pinch it off when done. If it is a metal tube, when you disconnect it, you may get a small amount of air in the M/C. You should be able to bleed this out when all the lines are connected.
Christopher Winter
You need the remote HYDRO-VAC with this brake system. It sends the pressure to the wheel cylinders(like a second master cylinder).
They did it this one year and then changed to a Treddle vac system the next year. Lucky you.
OK,,,Im back. I installed a used booster today, bled the top bleeder then the bottom one, then re attached the brakeline.,,,I have brakes,,,,BUT feels like stand brakes not power,,,,how do I know if the booster is working,,,,pedal is good but I have to push hard to stop,,,whats up,,,what did I do wrong
Check to see if the internal orifice of the booster hose is not collapsed.
Bruce. >:D
WHAT????? Talk to me like Im in grade 4
Quote from: The Tassie Devil(le) on October 29, 2016, 09:56:26 PM
Check to see if the internal orifice of the booster hose is not collapsed.
Bruce. >:D
The booster, if it is like other boosters of that era, has a large hose through which air passes when you apply the brakes. This is what gives you the boost. If that hose is collapsing internally, the air can't get through and you essentially only have manual brakes--actually worse than manual, since some of your effort is used to compress the booster without help from the air.
If you're expecting bleeding and adjusting is going to give you the same braking effect you're used to on your modern car or even one from 1962, forget it.
This is a 4 wheel drum brake car with a single master cylinder and old school brake assist(hydro vac). The Hydro vac was in service for years before 1957.
Also, these cars were designed around asbestos pads which reacted far differently than today's ceramic amalgamations.
On a 60 year old, 6000 pound car, be happy it even has power assist...
And you have s used booster. There's no knowledge of its usage or current effectiveness. These are "wet" boosters in that brake fluid that. By nature, absorbs water, could be rusty inside. All that and you have a commercial chassis...
Well today all installed and bled. I have brakes now a good pedal but I have to push it hard to stop. I would never atempt to drive this car on a highway. I think the booster is not working cause I did a test on it. Sat in the car pumped pedal 2 times and hold, then started the car. Pedal should of dropped a tad,,,,it didnt. I guess I will spend another 500 bucks and get the booster done,,,,,mmmm
You should definitely have it done but don't expect miracles from it. I've owned one of these for 23 years. The brakes are horrible. Get used to it.
Good thing its a hearse,,,I will drive real slow >:D Whats the alternitive to this brake system. Is there a M/C and booster from another car I can go with
Being a 58 owner, I have noticed a number of brake parts for my car are listed as fitting 56 and 58 but not 57....that always signaled to me that they knew they made things worse on 57s and had to go back.
Ed Strain at brakeboosterrebuild.com is often cited on this forum as a quality rebuilder of these boosters. Yours probably needs rebuilding.
There is a long thread on this forum regarding the possibility of retrofitting a modern dual master cylinder/booster setup on the 57, but my memory is that it would not be realistically feasible.
Ed E
How do you have the vacuum connected? There were 2 different ways. One had the vacuum hose attached to a pipe at the back of the carb. The other was directly off the intake manifold.
Both styles use a check valve attached to the firewall. There is no vvacuum ta k on the '57 so you can't pump the pedal and get it to pump up like a modern car. It'll only hold enough vacuum for 2 or 3 pedal applications.
Walter, I have no check valve on the firewall, my vac pipe comes out of the rear of intake directly to the booster
Without a valve, you'll never build up vacuum by pumping the brakes,with the car not running.
Quote from: Walter Youshock on October 31, 2016, 04:38:41 PM
How do you have the vacuum connected? There were 2 different ways. One had the vacuum hose attached to a pipe at the back of the carb. The other was directly off the intake manifold.
Both styles use a check valve attached to the firewall. There is no vvacuum ta k on the '57 so you can't pump the pedal and get it to pump up like a modern car. It'll only hold enough vacuum for 2 or 3 pedal applications.
2 or 3 applications with the engine off is all the manual promises for '58s, which do have a vacuum tank.
Mine is a 57 not a 58 which is a different system. I think my check valve is inside the booster. If Im wrong does anyone have a pic of it on the firewall or is there one in the manual.
I don't have a photo handy right now but can get you one. It's an L shooed poppet valve that attaches to the top right of the booster mounting bracket with a round clip. The vacuum hose from the intake goes on one port and the hose to the booster on the second port so it's in line. With your engine off, there's no vacuum that can be built up since at least some of the valves are in an open position.
The check valve also pprotects the booster in case there is a backfire from the carb.
Walt, the 57 is different, there is no check valve external on the hydro vac, later models had the canister type booster with that plastic check valve.
Really? Then why does my car have one?
Have a look at the picture: that check valve is really there. OK, it's a '57 Brougham, but the brake system is the same as for regular cars.
Odd, the 57 Seville I am working on does not have that set up, just a direct connection to the manifold?
The difference is probably due to the fact that the car above has a 2-carbs set up. From the parts book: (cars with 1 carb)
'57 before engine # 75598: part # 3715067 between intake pipe hose and booster hose
'57 after engine # 75597: part # 1469686 between carburator and booster
No matter where the check valve is located, there must be one!
Yep. Gotta be there.
Thanks for backing me up.
To be honest, the '57 shop manual does not mention it. The '58 manual does, but you know it's not the same brake system.
The Brougham shop manual ist just saying that the brake system ist mostly similar to the other '57 cars, just how it's installed on the cowl is different.
My car is a Brougham and I did not modify it to add that check valve.
Roger you are correct, someone in the past eliminated it on this car, it must have one as mentioned, I will get a modern one and splice it in, thanks for the follow ups by all!
Glad to be able to help, even if I'm not on the same continent!
Guys the check valve is in the booster check the manuel
OK,,,the best way to know this is who here has a 1957 cadillac reg carb,,,please let us know if you have a factory check valve inbetween the booster and intake,,,pics would be great
Here's mine:
Quote from: 60eldo on November 03, 2016, 08:21:31 PM
OK,,,the best way to know this is who here has a 1957 cadillac reg carb,,,please let us know if you have a factory check valve inbetween the booster and intake,,,pics would be great
My 1957 Cadillac Series 62 Sedan did. I have since sold the car. I'll try and find a picture if I can. It had the check valve between the pipe on the intake, and the brake booster. More modern/reliable booster/master combos can be put in the 1957. The only thing is that it will not be original to the engine bay. I converted the brake system on my 57' to a remanufactured master/booster from a 1967 cadillac. (This is the popular unit to convert the 59'/60' with. Which i've also done.) If you are comfortable with fabrication this would be easy for you. I always want to keep my cars original, but at the time, it was actually cheaper to fab up a new unit, then to get the hydrovac unit rebuilt. And I had already dumped $120.00 into the master cylinder, and was not going to keep putting money into a braking system that was "sub average" when new.
-Gavin
Got new booster NNNOOO FFUU ing BRAKES STILL, Pedal goes to the floor >:D
I have the dual quad factory setup and my check valve is in the same place as Walter's.
Thanks Dave where can I get one. OK now for the real story, new M/C, new booster, new wheel cyls, and hoses,,,,,,,,,,,all bled....I have no brakes, pedal goes to the floor but at one point I had a little padal but as soon as I start car it goes to the floor,,,,am I angry,,,,,you better believe it.
There are several sources of used Cadillac parts on the internet.
But the pedal going to the floor will not be fixed by the check valve.
When I got my Seville, there was pedal but no apparent power assist. I rebuilt the master cylinder, found and repaired all vacuum leaks, and adjusted the brakes per the service manual procedure. If I remember right adjust the starwheel until the drum is locked and then back off 14 clicks. And I think that the starwheel rotated in the opposite direction on the rear wheel cylinders than on the front when adjusting.
Now the system works pretty well for a power 4 wheel drum setup on a 5000 pound car.
I just read another post, and Im wondering. Is that on the bottom of the M/C a grease fitting, I hope it is cause now Im thinking its a bleeder screw in which case I never touched that,,,,Oh Oh
That's a grease fitting.
How is the reaction with the emergency brake? Is the travel excessive? Will it hold the car when applied? Does it release?
Seems your problem is more mechanical than hydraulic right now.
Interesting Walter, are you saying that MAYBE my shoes need adjusting, so when Im pressing the brake pedal the shoes are too far back and are not hitting the drum? Maybe
No clue but it's the next thing to check. The manual is very specific on the adjustments so follow it to the letter. You replaced all the return springs, readjusted the anchor pins, lubricated the shoes and anchor plates, etc.?
Will the pedal ever return to a somewhat normal position after a few hours or even overnight?
Woke up this morning went to car pressed and had a little brake 1 inch above the floor, then I changed my vac hose to a hydralic one seems a bit better, so with engine off I pressed brake down and up and held it down, started car and pedal rose,,,,shouldnt it drop? ::)
Hi Johnny:
Been following this saga. Any further developments to report?
Thanks,
Mike
I too am Curious, it also reminded me I did not post a picture of how mine is set up. I have never take this out of the car and I have only rebuild the wheel cylinders and replaced shoes so far. I can lock em up if I jump on it.
so my Vacuum comes from the front of the engine to the bottom of the booster and then the lines as documented in the picture. If there is a check value there is nothing on my system from the manifold to the booster as it is just rubber hose clamp connected to the two pipe fittings on each end.