Question on brake system compatability

[1940Mopar]

I'm trying to decide if I'm going to switch my brakes out to something that is a little easier to acquire parts for. My 1940 plymouth is one of those years where the entire brake system is different from the year before and the year after.

I'm staying away from disks right now, because I've got a bead on a mid 50s mopar from which I can yank the entire brake system including backing plates for under 200.00 bucks. I know this will mean that I may need to get new wheel cylinders and potentially even a master cylinder. but I really want to know whether in the end I'll be able to bolt everything up. I figured this was the best place to check

this is what my current setup looks like from the back.

[Captain Neon]

By the time you are done, you will have spent almost if not more than if you had just converted to disc brakes. If I was going to go to that much expense and trouble, I would switch to disc brakes.

[1940Mopar]

I understand the fully the disk option....what i don't is the drum option. Does anyone have a pic that could let me know whether the backing plate will slide over the spindle.

[Norm's Coupe]

I agree with Captain Neon. By the time you spend $200 for the 50 drum brake system, have the brake shoes relined for about $30 per set, and around $35 each for wheel cylinders, etc., you're up to between about $400 to $450 or more. You can put disc brakes on for between $500 to $600 or less. That doesn't count the master cylinder for either. However, with the disc brakes you can still use the same old master cylinder if it's in good shape. Then you can buy brake parts in any local auto parts store.

[Young Ed]

Here's the only pic I could find of my 48 stuff

[Young Ed]

I agree with the others the 200 seems over priced. With all the people converting to disks and doing street rods you should be able to get some for dirt cheap or free.

[Lou Earle]

I just looked up in Bernie's cataloge the basic parts and the parts for later models say 49 50 are the same price as for the 40 cars. If Bernie has the parts in stock why not just buy what u need from him - even if he is cantankerous- and rebuild what you have-his prices are close to napa's and soemtiems a littl echeaper- and be sure and check with napa- I bet your drums are OK so it is just a rebuild. By the way you can rebuild your own cylinders on the car or a shop can. I have done it several times. I have done the whole nine yards on brakes on several cars- believe me it is far better to stick with stock rather than venture into unknown swap territory and besides i do not think your swapping to later model system will improve it much -if any.

these brakes if done right are very reliable and do a good job - a lot better than a 48 ford but are harder to adjust.

Think it over-- nothing worse than getting 1/2 way in a swap and then regretting it. Good luck whatever you do.

Lou

[RobertKB]

I believe the master cylinders on your '40 and later models are totally different. I have a '38 and a '53 and there is no way to interchange. There are lots of vendors out there with the parts you need. I would stay with the '40 setup done properly. The one in my '38 is trouble-free and stops the car well.

[PatS....]

I have a couple of backing plates with the hardware from my '50 DeSoto parts car that are loose inside the car. You can have 'em for the shipping if you want.

Keep in mind the disc conversion from Charlie is reversible if you or a future owner would want to do that. I don't think the discs would impact the value of the car at all.

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[Plymouthy Adams]

The impact on value with the disc conversion..a definite increase in value to a car that will be driven..and to go from 40's brakes to 50's brake is lateral at best with no real advantage..cost is cost...and availablility..well right now I cannot name a discount parts store that you could wal in unannounced and buy a set of shoes..or cylinders..maybe a kit or two for the cylinder but would be a fluke more than the rule.

So in all due respect..stick with what you have and do them up right the first time and let it go

Install a disc kit for added safety and the benefit of RMA

[Captain Neon]

There's little to no benefit to switching from 1940 to 1956(?). I have the stock brakes in my P15, and I am content. However, if I was planning on doing such a big swap, I'd go to disc brakes and be done with it. If wanting availability of parts go with a disc brake set-up. The costs are similar, and you'll have much better brakes. You won't be doing yourself any favours switching to a 1950s brake system. Rebuild what you got or upgrade to disc.

[Jim Yergin]

When I bought my 1941 P12, it had the brake system from a P23 Plymouth. The only major change required to use the later backing plates is the spindle uprights. The originals on the '41 (and I believe it is the same for your '40) have four mounting points to bolt the backing plate and only three for the later. My car retained the original master cylinder and it all worked. I restored the car to the original '41 set-up but then decided to upgrade to disc brakes on all four wheels. To do so I had to go back to the later model spindle uprights. I also installed a dual reservoir master cylinder in the same location as the original master cylinder under the steering column.

The long and the short of it is that I think you can do what you want to do so long as you change out the front spindle uprights.

Jim Yergin