Lessons learned - Wheel cylinders and sealing stainless lines

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str12-340

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About two years ago I completely rebuilt the brakes in my 1970 Dart GT. Since then I have put about 13,0000 miles on the car. While many probably know this information, I did not, so I thought it would be good to post it here.

Replacing wheel cylinders - this is a lesson from my back brakes - 10 inch factory style drums. There is a foam gasket that comes with complete gasket sets that goes between the wheel cylinder and the backing plate. Somehow this seemed so unimportant that when I put mine together I neglected to install them. An oversight, not a conscious decision. I had the slightest leak (I mean really tiny) in the seal between the brake line and the wheel cylinder (this sealing issue is addressed next). Fluid seeped down the back of the wheel cylinder and without the gasket it seeped into the interior of the drum brakes. It was just enough to wet surfaces below the cylinder (hard to see when assembled) and brake dust from the shoes adhered to the film. Over time more seepage, more brake dust. When I removed the drum on that side there was a fist sized accumulation which explained the issues with lockup of that one drum when it was raining. (((sigh))) don't do what I did.

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I got all new brake lines and wanting to avoid corrosion got stainless lines - they didn't cost that much extra. I have stainless lines on one of my other Darts, but they were installed 20 years ago and I can't remember why I walked into a room 5 minutes ago. I had a really hard time getting several of the fittings to seal. I talked to Fine lines and they pointed out that the lines are much harder than stock mild steel lines and may require many rounds of loosen and tighten to get them sealed. One small line never did seal and Fine Lines sent me a mild steel version to solve the problem. I wailed and gnashed my teeth during this seemingly endless sealing process here on FABO, and someone here was kind enough to point out the availability on conical copper 'gaskets' to go between the two parts being sealed. This made great sense to me as I was provided with copper washer gaskets to seal the caliper hoses on the car (duh). I inserted these little devils in my leaking fittings and they sealed first try, no muss/no fuss. Why the companies that sell these stainless lines don't just send them with a brake line set is beyond me. If I had know I would have just put them in every fitting and saved myself many hours of work.

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I hope this saves some folks some time and effort.
 
So, actually if you had the copper washers, not installing the foam gasket wouldn't have mattered.
 
yeah, but if you drive your car and can't magically control the weather the same thing would have happened with splashed water. Chrysler rarely used parts that weren't needed in my experience. If they could have saved 25 cents per car, they would have left them out if it didn't lead to paying for warranty repairs within 50,000 miles.

Likewise, nobody cared about the long term - those dudes would be absolutely shocked at the number of 50 year old Mopars still on the street - so no stainless brake lines when mild steel would get you past the warranty.
 
Several years ago I plumbed my entire braking system with SS tubing - never again. I have good quality tools but the stainless was difficult to get a good flare on, was harder to bend and everything leaked. I went through the tighten/loosen/tighten process several times and could never get it 100%. Wish I would have found out about copper sealing washers when I was going through such a frustrating process. Good to hear they work. Frankly, they should not be necessary though, the flare is supposed to be the seal. Stainless is just too hard of a material to form.

I use coated steel line now. 100X easier to work with and doesn't corrode.
 
About two years ago I completely rebuilt the brakes in my 1970 Dart GT. Since then I have put about 13,0000 miles on the car. While many probably know this information, I did not, so I thought it would be good to post it here.

Replacing wheel cylinders - this is a lesson from my back brakes - 10 inch factory style drums. There is a foam gasket that comes with complete gasket sets that goes between the wheel cylinder and the backing plate. Somehow this seemed so unimportant that when I put mine together I neglected to install them. An oversight, not a conscious decision. I had the slightest leak (I mean really tiny) in the seal between the brake line and the wheel cylinder (this sealing issue is addressed next). Fluid seeped down the back of the wheel cylinder and without the gasket it seeped into the interior of the drum brakes. It was just enough to wet surfaces below the cylinder (hard to see when assembled) and brake dust from the shoes adhered to the film. Over time more seepage, more brake dust. When I removed the drum on that side there was a fist sized accumulation which explained the issues with lockup of that one drum when it was raining. (((sigh))) don't do what I did.

View attachment 1716339310

I got all new brake lines and wanting to avoid corrosion got stainless lines - they didn't cost that much extra. I have stainless lines on one of my other Darts, but they were installed 20 years ago and I can't remember why I walked into a room 5 minutes ago. I had a really hard time getting several of the fittings to seal. I talked to Fine lines and they pointed out that the lines are much harder than stock mild steel lines and may require many rounds of loosen and tighten to get them sealed. One small line never did seal and Fine Lines sent me a mild steel version to solve the problem. I wailed and gnashed my teeth during this seemingly endless sealing process here on FABO, and someone here was kind enough to point out the availability on conical copper 'gaskets' to go between the two parts being sealed. This made great sense to me as I was provided with copper washer gaskets to seal the caliper hoses on the car (duh). I inserted these little devils in my leaking fittings and they sealed first try, no muss/no fuss. Why the companies that sell these stainless lines don't just send them with a brake line set is beyond me. If I had know I would have just put them in every fitting and saved myself many hours of work.

View attachment 1716339312
View attachment 1716339313

I hope this saves some folks some time and effort.
Thx for sharing! I enjoy learning from what others have done.
 
str12-340, thanks for sharing, im doing a rotisserie Duster build with all new SS brake lines. I have not filled the system with fluid yet but im expecting leaks.
I would like to try your copper washers, could you provide a better pic of the box of washers so i can get the info, much appreciated for the tip..Rich
 
what you see is all the info on the box. I think they came from Grainger. I started a separate thread trying to find the information for sure and lots of folks posted sources on line. The key is getting them for the right size lines - I believe that it is 3/16, but take a look at the other thread.
 
There is a reason the factories used Bundy steel tubing for brake lines.......
It is relatively soft....& it seals......
The problem with using washers to fix the wrong choice of using s/s tubing....is that you now have two places that can leak instead of one...
 
Having been through the pain of making and attempting to adequately seal stainless steel fuel lines I believe that there is really only one correct fix and that’s not by using washers! I purchased a KOUL TOOLS Surseat P-51B Flare Lapping Tool and would recommend its use above and beyond using washers as a Band-Aid fix - especially on brake lines!

https://www.amazon.com.au/dp/B09YFGV1DK?tag=fabo03-20

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Years ago a friend of mine plumbed his show car with all polished stainless lines (fuel and brakes). He polished all of the lines and it looked good on display. Fast forward to him getting it running, all of the stainless lines leaked at every connection. He finally scrapped all of the stainless and installed factory hard lines, leakage problem solved.
 
what you see is all the info on the box. I think they came from Grainger. I started a separate thread trying to find the information for sure and lots of folks posted sources on line. The key is getting them for the right size lines - I believe that it is 3/16, but take a look at the other thread.
stupid question coming..... will Grainger sell to me if i just walk in or is it just tradesmen with established accounts?
we have a Grainger in my town, ive obviously never tried to shop there.
 
I made all my lines out of copper nickel tubing. Super easy to work with and seals ever time. I have never seen those copper seals before. Thanks for sharing
 
stupid question coming..... will Grainger sell to me if i just walk in or is it just tradesmen with established accounts?
we have a Grainger in my town, ive obviously never tried to shop there.
In 2023 I needed a small amount of an oddball zerk fitting they showed available on their website. Grainger was the only place who would sell less than 50 or 100. I ordered and paid for them online and picked them up at the store 20 miles from here. No issues.
 
stupid question coming..... will Grainger sell to me if i just walk in or is it just tradesmen with established accounts?
we have a Grainger in my town, ive obviously never tried to shop there.
They will sell to you if you walk in. They have more stuff than any of us will ever know!
 
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