bacelaw

Do you drill the backing plate to widen the holes to make that wheel cylinder fit, or are you saying the holes/ears on the wheel cylinders need expanding?

Amazing..@dpollo do you mean that the backing plate holes need to be drilled? This is the adapter I've used on my '41 on the rear brakes, curious if this is the one everyone uses https://shop.advanceautoparts.com/p/american-grease-stick-co.-brass-adapter-3-8-24-inverted-to-7-16-24-inverted-blf-22c/22190061-p?product_channel=local&store=7989&adtype=pla_with_promotion&product_channel=local&store_code=7989&gclid=Cj0KCQiAofieBhDXARIsAHTTldoS3AjNqrhsGTxL2_0RWuxFFKa9gP8rL2WR6Xi8VCr-jDZ7HdG5YCQaAnKAEALw_wcB&gclsrc=aw.ds

Thanks for everyone's help - for future forum searchers, here's what worked for me. The rear brake lines on my '41 wagon are 1/4" tubing. The inverted flare/double flare fittings are all 7/16-24, both out of the rear axle block and going to the rear wheel cylinders. However, the rear wheel cylinders have 3/8-24 female threads in them (for a 3/16" tubing) - you need a brass adapter at each rear wheel cylinder so the larger 1/4" tubing will plug into them. Advanced Auto, and probably all the parts stores sell an adapter that has 3/8-24 flare male on one end and 7/16-24 female on the other end to accept the brake line. We didn't even need a copper washer at the wheel cylinders, because the adapter bottoms out nicely and tightly. After some test driving, we could always add a copper washer if the brass isn't sealing at the wheel cylinder. I eventually got nicop lines as @Tired iron suggested. The nicop lines are crazy easy to work with, easy to bend, easy to flare, and are forgiving -even if the flare isn't perfect the material will mash together and seal. Thanks!

@vintage6t. That's exactly what I was looking for - that brass fitting bottoms-out in the wheel cylinder and doesn't appear to need any copper washer or anything. Thanks!

@Los_Control I'm with you 100%. I promised the previous owner that we would drive the wagon. I plan to drive it all Summer, daily if possible - the next owner can restore it to perfection. While I'm here, I'll drive it. The rear brakes had a terrible mix of fittings that never worked properly. So, I was trying to sort out what's correct and what's not. Apparently in '41 Plymouths had 1/4" brake lines in the rear. The rear wheel cylinders don't accept a 7/16-24 flare, so an adapter is required. The adapter is actually in the '41 parts book. The adapter either has 1/4" pipe threads going into the wheel cylinder or 3/16-24 male flares, and it allows a 7/26-24 flare fitting to attach. Thanks for everyone's help. I'll update once it's all put together

Most people are telling me that brass fitting is correct...thanks. No one yet knows the size, I think it may be 1/4" pipe threads into the cylinder and the brake fitting may be a 7/16-24 flare...when/if I figure it out I'll post results in case anyone else is stuck redoing a hodge podge of brake lines. This forum is great.

Thanks Chris..so the brass is required? It looks like 1/4 male pipe thread to a female flare fitting...I just dont know the size of the flare fitting and whether these brass are even available. Thanks!

I'm still struggling to find the proper setup. My rear wheel cylinders have a brass fitting in them (pic attached). I'm trying to find out if this is correct, and if it is, what threads/fittings are needed to button this up....or, if in the rear the brake lines can go directly into the cylinder without this brass on my '41 Plymouth. Fitting size and thread count has me dizzy 20230119_100212.heic

Thanks so much. Yes, the wagon has 10" drums. My problem is someone mixed metric and sae fittings in the rear and it's a mess. That Tee fitting looks like mine, but mine now has damaged threads. Any idea where to find one?

Hi all: new to the forum and working on my new-to-me 41 Plymouth Woody Wagon. I've searched through the archives, but here's my problem - Someone previously monkeyed up our rear brake lines. Does anyone know the flare/fitting size into the rear wheel cylinders? I know the front are different, what size fittings are those? I think they are both inverted flares, or should be. Also, the rear axle tee block that doubles as a vent for the axle - anyone have a picture of what it should look like? Thanks in advance!