40 Ply Leaky Brakes

[Don St Peter]

I've tried everything I know to stop a couple of brake cylinders from leaking since a complete brake job I did last year. New cylinders, new kits ( several ), new lines, etc. Since I am getting very tired of bleeding brakes and buying cans of DOT 5, which is very expensive, I need to "fix" the problem. The thing is I don't know what to do. When I disassemble I do not see damaged rubber or other problems. The cylinder walls are slightly pitted and a little rough, but they are new.

I'm about ready to go to the expense of having the cyl. walls chromed but thought I would ask the experts out there first.

Any suggestions

Thanks

Don

[Jerry Roberts]

New brake cylinder walls should not be " slightly pitted and a little rough " , they should be as smooth as glass . There are shops that will reline your existing cylinders with brass or stainless steel although new cylinders might be cheaper .

[Terry in Bozrah]

Hey Don

Let me ask you just a few question:

1. Did you replace the 60 year old brass fittings or did you clean and inspect them for cracks?

2. Did you use stock brake lines? No Stainless Steel, Al., Cuni or Nicu lines?

Some fittings have different angles for seating to different material tubes?

Are you using slotted box wrenches for a tight fit, makes a difference.

Someone asked me why I went through my rebuild and didn't use Stainless Steel.

My answer was 'The old steel brakes lines lasted 60 years,

I'm 50 (in a few days) and don't think I will out last my new steel brake lines I put on'.

Hope this helps, but others may have a better solution?

Terry

[billwillard]

Don, You should have no pitting. Very often NOS cyls will have pit from being stored in the wrong place. I would eather find new cyls with no pits or have yours sleeved. There are several cos that sleave these and warntee the for life.

Bill

[Don St Peter]

Since I know where the fluid is coming from.... the cylinders I need to deal with them, even if the are new. Probably should have returned them to Andy B when they were received somewhat pitted & rough but didn't. Live & learn. As for new brass fittings, I did not have to deal with them since the 40 did not use them.The old brake lines were in great shape so they did not need replacement.

Thanks for info

Don

[JIPJOBXX]

Can you locate the leak? Dry oft the fitting that go to the brake cylinder and get some Spot check developer. This spray on like wet but dry to a white powder. If you have a leak at your connection area this stuff will show it. Also you might spray some of this stuff on the brake cylinders itself and then drive for a short distance again this stuff really shows leaks as it is a powder when it drys sort of like talcum powder.

And you can buy a honing tool at a good car part store and re-hone your brake cylinder to help take out those pits. If those pits are right on the brake cylinder piston area when stopping they will leak by and cause your brake problem.

Spot Check Developer is used in None Destructive Testing. It good stuff and I know it works.

[Rodney Bullock]

I have a 1940 and after taking all of these wheel cly apart, only two were worth rebuilding. The cly may not be true and that why they are leaking. I had to buy two and my system was sealed. I guess depending on where you live you might be able to order some from a napa or such.

[BobT-47P15]

The wheel cylinders for a 40 model are "pre war" and not as easy to

find as the "post war" models, like 46-48. I bought new "post war"

front cyls for my Plymouth from O'Reilly Auto.

But, because my back brakes

are from a 39 model, I have gotten those cyls from good ole Bernbaum.

I have a couple from him sitting around right now, but have not looked

to see if they are pitted inside. Just guessing, but I think he must get

his cores that we trade in to him re-done to keep his supplies going.

There are some places that sleeve the cyls.....I think White Post

Restorations is one. Might be the way to go.

[Fluid drive]

Don:

Please do not be mislead by the appearance of the old brake lines , if you do not replace them you are gambling your safety and the safety of anyone that rides with you + your car. Old lines are DANGEROUS! they rust through from the inside out. Not to mention the fact that you cannot get them clean so chances are that you have already contaminated the new DOT 5 with the residue left in them.

As the fellows have told you new cylinders should not be pitted. Often they are because the old goop the factory used to assemble them dried up years ago and has drawn moisture. I would contact Mr. Bernbaum anyway and see if he will make good.

[Rodney Bullock]

Don't forget "kanter auto parts" they have lots of stuff for our cars. Billy up at white post can do a great job with your Wheel cly. There are alot of companies doing these you can take your pick.