1939 Chrysler Windsor Braking System

[MercMontMars]

Hi there, I’m posting in hopes of learning a bit more about my Chrysler’s braking system. There is no pressure on the brake pedal unsurprisingly, and it’s a system I’m not very used to. Before I go taking anything apart, what am I working with here? Haven’t been able to roll the car into my shop yet and look at all my lines or the system. Wondering if there’s a way to just fix it for now so I have brakes when rolling the car or testing it for very short distances. Don’t hear any hissing or pressure being made when the pedal is pushed so I’m assuming the cylinder or however this system makes pressure is shot. Will get photos and inspect more once I can get under the car more.

 

Thanks for any help!

[Oldtech]

Check if there is ANY fluid in it. Filling it up may give you enough brakes for around the yard. it may not work, and I'm sure in the longer term you are doing a complete brake overhaul anyway. It is a pretty standard hydraulic brake system.

[Bloo]

Have you bled it?

 

Brake fluid rots and attacks the metal parts. Since this looks like it has been rotting a while, I don't think I would bother. To get a pedal, you can take the cylinders apart and hone them and replace the cups. Cups can be bought individually by size at NAPA still. Get a brake hone and hone the cylinders. Don't overdo it. You can't make them new, and if you honed them that much they would be too big and never seal. You want to knock off anything that is high. Low spots can't be removed this way. If the springs inside the cylinders are rotted in two, or if the dust boots or pistons are completely shot, you might need to get whole kits. The cup is what holds the fluid in though. Lube everything with sil-glyde when you reassemble the cylinders. You will need a whole kit for the master cylinder because those cups are usually not available separately. Replace all rubber hoses no matter how good they look.

 

Flush out the steel brake lines with denatured alcohol. If they are full of crap, you can flush them out with brake cleaner because its easier, but do the alcohol afterward to get rid of moisture. Look them over real good for rust damage. They can and often do rust from the inside too. Be critical. If you find damage or if they are questionable just replace them. Reassemble everything and bleed the system. You should have a pedal. Check for leaks after a little use by peeling the dust boots back. All you should see in there is the sil-glyde you assembed the cylinders with. In a couple days check again. Any that are seeping will need sleeving or replacement. Some of them might not make the cut. Tiny leaks are not OK.

 

That is what an economy rebuild from 40 years ago looks like. A better way would be to just send out all the cylinders for sleeving and replace all the steel lines. Whatever you do, don't forget to replace the rubber lines. Yes, I said that twice. It is that important. Good luck.

 

Edited September 25, 2023 by Bloo (see edit history)

[maok]

Can you not use the hand/emergency brake? Or are the brakes locked up? If so, free play adjustment of the brake pedal is very critical to proper functioning braking system.

[marcapra]

You have Lockheed brakes.  You can learn about them by watching the filmstrips shown at Mopar.com.  https://mymopar.com/mtsc-1948-volume-1-8-an-even-brake/

[MercMontMars]

@maok Not sure, when I pull the handbrake it moves but doesn’t stay clicked. Might be able to free it enough to use it, haven’t rolled the car enough to really test it. Car rolls freely so I don’t think the brake is stuck thankfully.

[MercMontMars]

@Bloo Thank you for all this great info! I will be utilizing all of it once I get to fixing up my brake system. I haven’t bled it yet. I absolutely plan on doing a full overhaul eventually, probably after the car proves to be a worthy runner and I need them to make her road safe. 

Edited September 25, 2023 by MercMontMars (see edit history)

[mobileparts]

If you need or want, or just want to start fresh with gorgeous brand new current U.S.A. made parts, 

I have the Master Cylinder,  Wheel Cylinders,  Brake Hoses, and Brake Shoes.....

[MercMontMars]

@mobileparts I’d love to, and eventually will need to. Please message me on what your price is for the full kit. 

[TerryB]

If you assume everything is shot and needs replacement you probably won’t be disappointed!  If you’re new to MoPar Lockheed brakes watch some episodes of Keith’s garage on YouTube.  He does some videos on the brakes on his 1938 Plymouth.

[Rusty_OToole]

You could try filling the master cylinder. You never know your luck. Do not step on the pedal before you do this, or chances are the piston in the master will stick at the bottom of the cylinder.

 

Chrysler brakes were state of the art for the times and more difficult to set up than the loose leaf brakes used on cheaper makes. To get them to work perfect you need to arch the shoes to match the drums and then adjust the brakes for full contact. That is the major adjustment. After that you only need a minor adjustment from time to time, to take up wear.

 

You should also know the rear hubs are tapered and wedge onto the axle shaft. After 50 years or more they grow together and don't want to come apart, you need a very big, strong puller to get them apart.

 

Best advice is to buy a factory repair manual and go by it if you have to work on the brakes.

 

Also, the hand brake is on the back of the transmission and is completely separate from the service brakes. Unfortunately it can get oil and grease on the lining if the trans seal leaks, and the cables and linkage can get stiff but in most cases still works a little bit even if not perfect.

[Bloo]

Yes, don't push the pedal all the way down. Even if it doesn't stick you would still be dragging the cup across rust. If you fill it, and you haven't bled it, wait a day before trying the pedal.

 

[MercMontMars]

Looks like my master cylinder might be up in there, I’m not really sure how to access it. 
 

[Bloo]

Probably take a floorboard out. Maybe a plug. Look at the driver's floor closely.

 

[61polara]

Roll the front floor mat back and you will see an access cover plate.  Remove it and you will see the cap on the master cylinder.

[bryankazmer]

I don’t know if 39 is the same, but my 41 had stepped wheel cylinders. You could only push the guts out one way

 

i assume you’ve found out that one side has left hand wheel lugs

[marcapra]

If the 39 is like my 48 DeSoto, removing the MC is a real bear.  you have to remove the brake and clutch pedals off of the shaft that runs through the MC! Here is a blow up of the handbrake for my 48.   

[TerryB]

The 39 Chrysler uses step bore wheel cylinders.  That means the left side and the right side are different from each other to get the different size bores in the correct orientation.  Looking on eBay I see some sellers fail to mention what side their cylinders fit so beware of this so you don’t wind up with the wrong thing.

[mobileparts]

And the Master Cylinder is N O T the same for 1939 & 1948…..

 

The application is 1937 - 1942 …. And then, after the war,

1946 - 1954…..

 

1000 % different….. (I made them both, of course…. And the 1930 - 1936…..)….

 

Craig…..

[marcapra]

If I remember, the prewar MCs had only one brake line coming out the back of the MC, while the post war cars had two, one line going to the rear axle, and the other going to the front.  Did the prewar MCs have the pedal shaft going through the MC like the post war cars?

[marcapra]

Looks like Chrysler changed over to the new MC in 1941 pictured below on the bottom.  1940 was the last year of the older MC pictured below.  Looks like the pedals are not suspended on a shaft on the old style MC

Edited September 27, 2023 by marcapra (see edit history)

[mobileparts]

Actually and Definitively, and in Reality, the First Master Cylinder pictured above was used from 1937 - 1940 - A L L - as in Chrysler, Dodge , De Soto, and Plymouth….

and 1941 - 1942 95 % of Dodge, and Plymouth, and 75 % of Chrysler , and De Soto….

 

the Second Master Cylinder pictured above was used from

1946 - 1954  - A L L - as in Chrysler ,Dodge ,De Soto, and Plymouth,

and 1941 - 1942 5 % of Dodge, and Plymouth, and 25 % of Chrysler, and De Soto…..

 

Thank you for those beautiful pictures…. I wish I knew how to do that…

I want to learn how to do that…I wish I could do some of this 22nd century stuff….

For some things, I am still a 19th and 20th century guy / dinosaur !! 
 

Craig…..

[MercMontMars]

I’ve put in a new gasket and filled up the cylinder, I wanted to check what could be inside it before filling it up. It’s all put together now, but I’m still not getting anything. Straight to the floor. I’m guessing it’s either totally shot or the piston could be stuck. Either way it’s not the worst thing ever, I plan on overhauling the system once the car can drive and until then the emergency brake works. 

[GARY F]

A full brake bleed first.

[pfloro]

13 hours ago, MercMontMars said:

I’ve put in a new gasket and filled up the cylinder

As is the case with "newer" MCs, I believe your new MC needs to be "bench bled" to remove all the air from the MC itself.

You would then install it in the car and connect the line...

 

Paul

 

How to Bench Bleed

Bench bleeding is especially useful with new master cylinders. It's a great way to get air out of the cylinder itself and begin your brake bleeding process quickly and easily. You can get bench bleeding kits from any number of places, but we picked ours up at Classic Performance Parts when obtaining a brake kit. Here's how to begin:

• Install the plastic fittings and clear tubes
• Place the master cylinder in a vice and make sure it's level
• Fill the master cylinder with a fresh, high quality brake fluid (DOT 3 was ideal for our hot rod)
• We used a short extension commonly found in your rachet drawer to stroke the master cylinder piston, thereby forcing the air out of the master cylinder and up and through the plastic hoses. Note the bubbles within the clear tubes in the photos.
• Once this is done, you can use one of the clear bleeder hoses and leave it attached to one of the fittings. Take the other end and attach to the other fitting until installed in your car. In our case, we had rubber plugs that we placed over the end of each plastic fittings.

 

[Oldtech]

15 hours ago, MercMontMars said:

I’ve put in a new gasket and filled up the cylinder, I wanted to check what could be inside it before filling it up. It’s all put together now, but I’m still not getting anything. Straight to the floor. I’m guessing it’s either totally shot or the piston could be stuck. Either way it’s not the worst thing ever, I plan on overhauling the system once the car can drive and until then the emergency brake works. 

Considering where we started, (just to have yard brakes), it looks like there isn't a quick fix. I'm fairly sure the piston will be stuck at the end of it's travel.  While it could soften up and come loose it looks like the only solution is to pull the master cylinder and rebuild it. 

[pfloro]

3 hours ago, Oldtech said:

I'm fairly sure the piston will be stuck at the end of it's travel.  While it could soften up and come loose it looks like the only solution is to pull the master cylinder and rebuild it. 

 

Oops...  From the the pictures, I assumed that you had changed out the MC...   I think that Oldtech is spot on...

 

Paul

[The 55er]

Due to the fact that your car was sitting so long, IMO you're not going to get any kind of a pedal until you repair, rebuild (or better yet replace) every hydraulic component of the brake system including the master and all four of the wheel cylinders. Since you're dealing with a lot of unknowns on an 84 year old vehicle it would also be good practice to replace the the old steel and flexible lines. You might want to replace the shoes & lining and have the drums turmed as well while everything's apart. If you decide to restore the entire car, a complete brake system overhaul is the only way to go. Safety first, fix it once and fix it right. Just my 2 cents.

[m-mman]

13 hours ago, The 55er said:

every hydraulic component of the brake system including the master and all four of the wheel cylinders

Correct but I feel a need to include all the hoses also. 

I have seen too many people look at the outside of brake hoses conclude that “They don’t look cracked, I’ll just use them”. 
 

No, they collapse inside and don’t pass fluid. 
 

There is nothing more important on a car than the brake system. Fix it completely and don’t take any shortcuts. 

[MercMontMars]

So today while tinkering with the car I tried the brake pedal and it actually has a little resistance now. I checked the cylinder reservoir and it was dry, suggesting the fluid went somewhere. This happened after the car sat for a couple days. What might’ve happened here? When the pedal is pressed it doesn’t feel like I’m applying the brakes, it just has a bit of resistance now as opposed to before where it’d just go straight to the floor. When I pushed the car in for the night I had a harder time pushing it so the brakes must be doing something. I don’t know why they’d be applied with no one pushing the pedal.
 

I plan on overhauling the braking system once the car is good and I can drive it on the road, but if I can get the brakes to work just enough for testing in my lot that’d be perfect. 

[JACK M]

You may have broken loose at least one wheel cylinder and it then may have stuck in a more "applied" position.

I can pretty much guarantee you that the brake system will be totally rusted after all those years of nonuse.

[nsbrassnut]

An old story. Be sure that you have control of the car when testing the old brakes. When I first got my '36 Packard and tried out the brakes in the rental garage where it was sitting, I heard a "pop" and the pedal then went to the floor. One of the rear lines was rusted thin and blew out the first time it was pushed hard.

 

In the case of the master cylinder. With some the bleed hole for fluid from the reservoir to the master cylinder is small and it can take a while for the fluid to drain down into an empty cylinder the first time when only gravity is pushing it down. Hence the fluid level went down, but very slowly.

 

When the system is completely filled, any make up fluid required is "sucked in" when the pedal comes back up.

 

A full front to back, cylinders, hoses and lines brake rebuilt is a good plan and will serve you well when its completed.

 

Good luck with the project.

[keithb7]

A master cylinder kit is not expensive. Just measure the bore of your cylinder to ensure you get the correct kit. Just because you see another Mopar master cylinder that looks just like yours, it could have a different bore. I learned this the hard way. 
 

The original Mopar manuals that I have seem to miss the position of 1 rubber washer. It is seen in this image from my Motors Manual. Far left here, valve seat. 
 

 

Thank you to folks who are recommending my You Tube Channel. Its purpose is to help others with their old Mopars.    https://youtube.com/@keithsgarage5831?si=0NPxciG-BsXeoUkF

 

I have salvaged questionable looking master and wheel cylinders. A little elbow grease and emery cloth can usually get them sealed and working again. - Keith

 

Edited October 20, 2023 by keithb7 (see edit history)

[EThomas]

Having just went thru this with a car that sat in a museum for 20 years, you will need to do a full and complete brake system rebuild. The hydraulic fluid will have damaged everything from sitting. It may not look like it from the outside; however, it has.

 

I had everything from the drums in replaced - pads, wheel cylinders, lines, master cylinder - the full nine yards. You'll also need to have your parking brake serviced and repaired as well.

 

I know it's not the news you're looking for. It wasn't the news I wanted either.

[mobileparts]

I need these pictures up top…

[R Walling]

 I have found that when the brake pedal goes right down to the floor, you may be able to blead the master cylinder by carefully pumping of the brake pedal with your hand. (Never Push it all the way down again with a dry cylinder)

 

 First, fill the cylinder and leave the cap off.

 Second, push the pedal down about an 1/8' and release. After a few times you may see air bubbling up. Wait for the bubbles to stop and then, continue taping the pedal lightly as more air bubbles come up. You may get a solid pedal after all the bubbles stop coming up.

 

 It has worked for me on several cars.