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Cadillac & LaSalle Club Forums => Technical / Authenticity => Topic started by: Daffer on July 07, 2025, 10:30:57 PM

Title: 1950 cadillac drum brakes questions
Post by: Daffer on July 07, 2025, 10:30:57 PM
Im getting my brakes done and new tires in about a week im buying all the parts but im wondering what should be replaced when I go about this process. I also would like to know what brake fluid is recommended I've seen a few people say dot 5. Also is it necessary to have my brake lines changed to stainless, I've read alot of people do that aswell. Thank you in advance as always for all the help!
Title: Re: 1950 cadillac drum brakes questions
Post by: Jeff Rosansky CLC #28373 on July 08, 2025, 11:20:24 AM
I believe you need to really replace everything to go to the Dot5. That means master and wheel cylinders, and a good line flushing. Others here will chime in, but if so that will get pretty expensive.
When I did my brakes, I got all new wheel hardware- New springs and hold down pins. If you dont go to that degree, be sure to at least look at the hold down pins. Mine had some pitting at the back and would have failed.
I just went with standard lines.
I dont know if you are talking about an actual 50, or 50's. But if you have power brakes, be sure they are bled according to the manual.
Title: Re: 1950 cadillac drum brakes questions
Post by: Daffer on July 08, 2025, 12:15:41 PM
Quote from: Jeff Rosansky CLC #28373 on July 08, 2025, 11:20:24 AMI believe you need to really replace everything to go to the Dot5. That means master and wheel cylinders, and a good line flushing. Others here will chime in, but if so that will get pretty expensive.
When I did my brakes, I got all new wheel hardware- New springs and hold down pins. If you dont go to that degree, be sure to at least look at the hold down pins. Mine had some pitting at the back and would have failed.
I just went with standard lines.
I dont know if you are talking about an actual 50, or 50's. But if you have power brakes, be sure they are bled according to the manual.
Now the "hold down pins" is that the pin with the flat flare on the end? As for the lines im gonna have my mechanic look them over to be safe but if they are good I was wondering if its fine to keep them or shoukd they be swapped for stainless. Its a straight 1950 for the year.
Title: Re: 1950 cadillac drum brakes questions
Post by: Big Fins on July 08, 2025, 01:29:16 PM
There is DOT 5, which is a silicone based fluid. That will require basically changing anything that the brake fluid touches. Then there is DOT 5.1 which is compatible with the other types of fluid EXCEPT DOT 5.      5.1 has a higher heat capability.

The hold down pins are the two pins on each side of the backing plate that go through the backing plate, from the back side,  through the shoe and have the spring and cupped connecting washer that everyone wants to think will be easy with pliers.

There is special line sold as brake line. They are usually sold in 6' sections that you can shape yourself and they use a flare fitting to connect the sections together. NAPA has them.

Put a little dab of white lithium grease at the contact points of each shoe at the anchors, backing plate contact points and where any other hardware connects to the shoe. It helps to stop squeaks, rattles and it lubricates the movement of the shoe system.
Title: Re: 1950 cadillac drum brakes questions
Post by: Jay Friedman on July 08, 2025, 01:36:20 PM
Good advice from Jeff and Big Fins.

I suggest the following:

1. Change to stainless steel hydraulic lines (that won't rust);

2. Have your master and wheel cylinders sleeved with brass or stainless (so they won't rust);

(The reason for the above is brake fluid attracts moisture--I think the word is "hydrophilic"--which causes ordinary steel lines and cylinders to rust. I have stainless lines and sleeved cylinders on my '49 and have never had any problems with rust.)

3. Stay with the original DOT 3 brake fluid.  If you switch to DOT 5 you will have problems.  On our vintage cars I've seen brakes "locking up" and other problems with DOT 5, in addition to everything Jeff Rosansky mentioned. 

4. Yes, replace the hold down pins and the small springs and cups that go with them. 

However, I suggest you keep the original large brake shoe retracting springs. The reason is the strength of these springs varied quite a bit from year to year and model to model. (According to my 1935-55 Master Parts book there are 7 different spring part numbers from the mid 30s to mid 50s.) I think the springs available commercially today are generic. 

I had this problem with my '49 a couple of years ago after having replaced these springs with new ones when doing a brake job. One wheel then would frequently lock up.  My friend Art Gardner (The Caddy Wizard) found that the new springs I installed were weaker than the originals, so one of the shoes on the wheel in question would not always retract.  Luckily I had not thrown away the original springs, so after re-installing them the problem was resolved.  I think it is rare that these springs break or fail in some way.

Title: Re: 1950 cadillac drum brakes questions
Post by: Daffer on July 08, 2025, 04:51:54 PM
Quote from: Jay Friedman on July 08, 2025, 01:36:20 PMGood advice from Jeff and Big Fins.

I suggest the following:

1. Change to stainless steel hydraulic lines (that won't rust);

2. Have your master and wheel cylinders sleeved with brass or stainless (so they won't rust);

(The reason for the above is brake fluid attracts moisture--I think the word is "hydrophilic"--which causes ordinary steel lines and cylinders to rust. I have stainless lines and sleeved cylinders on my '49 and have never had any problems with rust.)

3. Stay with the original DOT 3 brake fluid.  If you switch to DOT 5 you will have problems.  On our vintage cars I've seen brakes "locking up" and other problems with DOT 5, in addition to everything Jeff Rosansky mentioned. 

4. Yes, replace the hold down pins and the small springs and cups that go with them. 

However, I suggest you keep the original large brake shoe retracting springs. The reason is the strength of these springs varied quite a bit from year to year and model to model. (According to my 1935-55 Master Parts book there are 7 different spring part numbers from the mid 30s to mid 50s.) I think the springs available commercially today are generic. 

I had this problem with my '49 a couple of years ago after having replaced these springs with new ones when doing a brake job. One wheel then would frequently lock up.  My friend Art Gardner (The Caddy Wizard) found that the new springs I installed were weaker than the originals, so one of the shoes on the wheel in question would not always retract.  Luckily I had not thrown away the original springs, so after re-installing them the problem was resolved.  I think it is rare that these springs break or fail in some way.



ok got it, I really appreciate the advice on the large brake shoe spring, ill be sure to keep it and use it. (ill be honest I never through out old parts for those just incase moments lol". now with re-sleeving is this something that many shops do or is this done at a special place? would it be recommended just to replace them with new ones and if so would they need to be re-sleecved if there brand new?
Title: Re: 1950 cadillac drum brakes questions
Post by: Jay Friedman on July 08, 2025, 05:51:53 PM
White Post Restorations in Virginia does re-sleeving.  https://whitepost.com/

Also Apple Hydraulics.  https://www.applehydraulicsonline.com/

I've dealt with both these firms.

Another firm which does this is http://www.karpspb.com/sleeving, though I've never dealt with them.

Inline Tube sells pre-formed stainless steel hydraulic lines.  https://www.inlinetube.com/
Title: Re: 1950 cadillac drum brakes questions
Post by: Daffer on July 08, 2025, 07:13:33 PM
Quote from: Jay Friedman on July 08, 2025, 05:51:53 PMWhite Post Restorations in Virginia does re-sleeving.  https://whitepost.com/

Also Apple Hydraulics.  https://www.applehydraulicsonline.com/

I've dealt with both these firms.

Another firm which does this is http://www.karpspb.com/sleeving, though I've never dealt with them.

Inline Tube sells pre-formed stainless steel hydraulic lines.  https://www.inlinetube.com/
Thank you so much for those websites!
Just one question if I have brand new cylinders is it necessary to have them re-sleeved?
Title: Re: 1950 cadillac drum brakes questions
Post by: Jay Friedman on July 08, 2025, 09:58:43 PM
The brand new cylinders will be made of steel and so can eventually rust.  In my opinion you would be better off long-term having your used wheel cylinders sleeved rather than buying new ones. Others may disagree.  Also, I don't know what the difference in cost would be.
Title: Re: 1950 cadillac drum brakes questions
Post by: Daffer on July 08, 2025, 10:16:53 PM
Quote from: Jay Friedman on July 08, 2025, 09:58:43 PMThe brand new cylinders will be made of steel and so can eventually rust.  In my opinion you would be better off long-term having your used wheel cylinders sleeved rather than buying new ones. Others may disagree.  Also, I don't know what the difference in cost would be.

ahhhh ok thanks that's going to be something for me to look up then. I really appreciate all the advice from everyone thank you so much! any other advice people have is much appreciated
Title: Re: 1950 cadillac drum brakes questions
Post by: Warren Rauch #4286 on July 09, 2025, 08:57:54 AM
        Lots of different opinions ,pretty much all right. My two cents.

     DOT3 vs Dot5  On cars that the air is in contact with the fluid in the master cylinder ,there will be moisture absorbed by Dot 3.  Dot5 does not do that. They can be mixed,but any dot 3 in the system will still be a problem. If you use Dot 5, it can be hard to  get on the road for top offs. Someone that does not know will likely top it with dot 3, your loss.

     Stainless lines, Should be standard on all new cars. Brake line rust is a major reason for brake failure. On collector cars, they look like new forever. They won't rust on the inside ever, but I've never seen rust inside even lines leaking from rust on the outside. Standard lines in areas that don't use salt,or on cars not driven on salted roads , seldom get more than a surface rust on the outside of the lines.

   New Cylinders, when available for old models are often cheaper than sleeving them.  If you use dot5 and change them all (wheel,master,booster) no problem.   With any  dot3 in the system, they may rust after a long time. (Every time you step on brakes,the master can add moisture to the fluid.) The manufactures think it is a good tradeoff not to sleeve or use stainless cylinders.

  Springs, pins,etc should be replaced, if they are pitted,don't match side to side or show other defects.  Return springs can still be a problem because old ones may not be as strong as new.

Warren

     
Title: Re: 1950 cadillac drum brakes questions
Post by: TJ Hopland on July 09, 2025, 10:09:40 AM
Stainless is a pain to work with and really seems to aggravate corrosion on things it is in contact with.  NiCopp has been around for a while now and seems to be holding up well.   I have only been using it for a few years and even in my area regular steel lines would last that long but so far so good.  Its for sure the easiest to work with.  The small stuff is almost like working with hose.  Even working solo you can just about just pull it through and around things.  Its safer and faster if you can get an assistant to help guide things because if it does kink you have to splice or start over.     
Title: Re: 1950 cadillac drum brakes questions
Post by: Jeff Rosansky CLC #28373 on July 09, 2025, 11:11:21 AM
I just used the NiCopp lines that Napa places had. Sold in sections. I bought new cylinders because they were a lot cheaper than having the originals resleeved. Full disclosure on that though  mine were very badly corroded.
I had the master and booster rebuilt. I can do a master, but I dont have the ability to resleeve in my garage.

I would very strongly suggest new lines. A lot of pressure goes thru them in a panic stop, and they are 75 years old and rust from the inside out.
Title: Re: 1950 cadillac drum brakes questions
Post by: Daffer on July 09, 2025, 05:27:56 PM
wow a lot of great Information Thank you so much!! I didn't think id have anymore questions but when going to purchase a spring kit I came across 2 others and I'm not sure which one is correct maybe someone will know or maybe there both good i just don't know (the return spring is different in each kit by the looks)

 
Title: Re: 1950 cadillac drum brakes questions
Post by: Davidcamper on July 09, 2025, 07:06:16 PM
Your biggest challenge is finding the correct brake shoes. 50-51 are unique and 49, 52, 53 do not fit. Lots of auto parts sell you the shoes only to get them and they do not fit. I just did all 4 of mine with all new cylinders, lines, hoses and master cylinder. The key here is 11"x2-1/2" brake shoes. 1949, 1952 and up are not this size. Remember, one shoe has more pad than the other. Watch how you remove them, it's important you place the shoe with the most pad in the right location on the hub.
Title: Re: 1950 cadillac drum brakes questions
Post by: Davidcamper on July 09, 2025, 07:11:47 PM
Front brakes 1951
Title: Re: 1950 cadillac drum brakes questions
Post by: Davidcamper on July 09, 2025, 07:31:33 PM
Pic of springs on the left is correct. The pic on the right I have no idea what those fit. Certainly not 50-51.
Title: Re: 1950 cadillac drum brakes questions
Post by: Daffer on July 09, 2025, 10:06:46 PM
Quote from: DavidcamperYour biggest challenge is finding the correct brake shoes. 50-51 are unique and 49, 52, 53 do not fit. Lots of auto parts sell you the shoes only to get them and they do not fit. I just did all 4 of mine with all new cylinders, lines, hoses and master cylinder. The key here is 11"x2-1/2" brake shoes. 1949, 1952 and up are not this size. Remember, one shoe has more pad than the other. Watch how you remove them, it's important you place the shoe with the most pad in the right location on the hub.

thanks for the photos and the info! the brake shoes I found  say there 11.031 x 2.5 you think the .031 is a big deal?
Title: Re: 1950 cadillac drum brakes questions
Post by: Roger Zimmermann on July 10, 2025, 04:43:18 AM
My impression is that 0.031 is for oversized drums. If you still have the nominal drums at 11", you'll have to adjust the shoes (by removeng material) to have contact with the drum on the entire shoe's surface.
Title: Re: 1950 cadillac drum brakes questions
Post by: Jeff Rosansky CLC #28373 on July 10, 2025, 11:04:34 AM
I took my old springs and other hardware to my local Carquest. They have guys there who have actually not only checked the oil on a car, but have actually worked on them.
The guy behind the counter got out an old grease covered dog-eared catalog about the size of an old phonebook. He painstakingly matched up each spring and part to the catalog and just ordered me a set from there. Worked perfectly.

My local Autozone had the shoes in their system. They worked but it sounded like a school bus. I returned them and got a set from Napa. They work fine.
I dont have a machine to arc them, but I put a little baby powder on them and spun the drums and they seemed to fit well...... Yes, I cleaned it up, but she smelled like a fresh baby's bottom the 1st 100 miles or so 🙂.
Title: Re: 1950 cadillac drum brakes questions
Post by: TJ Hopland on July 10, 2025, 11:33:29 PM
Whats the deal with the baby powder?
Title: Re: 1950 cadillac drum brakes questions
Post by: Jay Friedman on July 11, 2025, 09:09:45 AM

Quote from: TJ Hopland on July 10, 2025, 11:33:29 PMWhats the deal with the baby powder?

I think the idea with baby powder is to test whether the lining presses against the drums evenly along its length. I'm guessing the baby powder is rubbed off where the lining presses against the drums and remains visible where is does not.


 



Title: Re: 1950 cadillac drum brakes questions
Post by: Davidcamper on July 12, 2025, 01:28:19 PM
Example of what moisture can do inside brake wheel cylinders.
Title: Re: 1950 cadillac drum brakes questions
Post by: Lexi on July 12, 2025, 04:11:23 PM
Very nice shots. Thanks for posting. Clay/Lexi