Drum Brake Wheel Cylinder Evaluation

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Brad Ripley
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Re: Drum Brake Wheel Cylinder Evaluation

#16 Post by Brad Ripley »

Aren't we talking about wheel cylinders ?; how did we get into master cylinders ?

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Patrick Ertel
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Re: Drum Brake Wheel Cylinder Evaluation

#17 Post by Patrick Ertel »

You open a whole can of worms when you mess with 356 wheel cylinders.
The 19mm wheel cylinders used on 356s (and some VWs) were actually 3/4" so if you're cheap or desperate you can use over-the-counter 3/4" brake cups from your FLAPS.
Many people state that VW wheel cylinder kits will work, without any caveat. So here is your caveat - VW used 19 mm (3/4") wheel cylinders (the same as SOME 356s) only from 1958 to 1964. After that they went to 20 or 21mm.
Some 356s used 20 mm rear wheel cylinders (these are actually 13/16"). The kits that Stoddard sells are for 19mm cylinders only. The 13/16" brake cups are not easy to find anywhere. I did find a NAPA counter man who did the work to locate some. I think they cost $1.25 each.
The 19mm replacement cylinders work fine on cars originally with 20mm cylinders so unless you have pristine 20mm cylinders and you just want to replace the rubber parts I recommend you opt for new replacements.
An FTE brand front brake cylinder seized up on my car after only 5 years, so try to get genuine ATE parts.
Last edited by Patrick Ertel on Fri Dec 02, 2022 9:03 am, edited 1 time in total.
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Jim Liberty
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Re: Drum Brake Wheel Cylinder Evaluation

#18 Post by Jim Liberty »

Al, I agree except I only put dual masters on track cars. Never had a problem with the factory set-up. That said, your suggestion is certainly better. .........Jim.
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Harlan Halsey
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Re: Drum Brake Wheel Cylinder Evaluation

#19 Post by Harlan Halsey »

Patrick Ertel wrote: Thu Dec 01, 2022 4:19 pm You open a whole can of worms when you mess with 356 wheel cylinders.
An FTE brand front brake cylinder seized up on my car after only 5 years, so try to get genuine ATE parts.
356 brake cylinders are pretty simple. Just a cylinder, elastic cup, two-part piston, and a dust cover. There are two failure modes, wear of the cup or corrosion. Originally the brake cups lasted more than 100,000 miles. Internal corrosion from water drawn into the fluid from the air causes roughness in the cylinder wall which damages the cup causing a leak. External corrosion of the cup pusher which is made of pot metal causes friction with the cylinder wall. I suppose that in road salt environments this could be a problem although I never experienced it when I lived near Boston. However, I have rebuilt junk cylinders which had bad pushers simply by making new ones of aluminum.
Porsche put 20mm cylinders on the rear of a very few cars. We speculated that these were Carreras. These cylinders have "20" replacing the usual "19" cast in. Somewhere around here is a lathe jig I made to bore brake cylinders because I wanted to try larger cylinders on my GT track Carrera. Made no difference as far as I can tell. While 20 mm brake cups are hard to come by American 13/16" cups worked fine as do 3/4" American cups in 19mm cylinders. I suspect that the American brake cups are of a quality at least as good as anything ATE supplied.
In the extremely unlikely situation that I had good 20mm units and not enough 19mm ones, I would not hesitate to install the 20mm units as long as I did it symmetrically side to side.
As far as the master cylinder goes, it is similar to the brake cylinder-same issues, same solution. I'm certain that I can and have assembled a master cylinder just as well as some workman in Germany or China.

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Vic Skirmants
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Re: Drum Brake Wheel Cylinder Evaluation

#20 Post by Vic Skirmants »

My 1958 Normal coupe had 20mm rear brake cylinders. I have seen quite a few over the years, not just on Carreras. Bill Romig ran 17mm VW rear cylinders; he felt that a 356 did not need excess rear braking.

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Patrick Ertel
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Re: Drum Brake Wheel Cylinder Evaluation

#21 Post by Patrick Ertel »

I got "lucky" enough to find a pair of 20mm cylinders on the 741 transmission in my '56 coupe. I don't think the trans came out of a Carrera.
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Bil Brown
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Re: Drum Brake Wheel Cylinder Evaluation

#22 Post by Bil Brown »

We sleeved over 1700 wheel cylinders with stainless some years back.....until my machinist passed. Half of the rear cylinders were 20mm cylinders........and we sleeved them down to 19mm. I`ve still got a 50 pound wooden box full of old wheel cylinders. Hope all`s well Patrick.....been many years!
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Martin Benade
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Re: Drum Brake Wheel Cylinder Evaluation

#23 Post by Martin Benade »

That’s a lot of cylinders without broken bleeders! Must not be from northeastern Ohio.
Cleveland Ohio
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Bil Brown
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Re: Drum Brake Wheel Cylinder Evaluation

#24 Post by Bil Brown »

We had a lot of broken bleeders, but my machinist Harry, had no problem getting them out.....HEAT did it..........he was good!
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Patrick Ertel
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Re: Drum Brake Wheel Cylinder Evaluation

#25 Post by Patrick Ertel »

bil brown wrote: Fri Dec 02, 2022 10:51 am We sleeved over 1700 wheel cylinders with stainless some years back.....until my machinist passed. Half of the rear cylinders were 20mm cylinders........and we sleeved them down to 19mm. I`ve still got a 50 pound wooden box full of old wheel cylinders. Hope all`s well Patrick.....been many years!
There was a time when sleeving them was cheaper than buying new. The guys with the skill and machinery and the will to do it for the love of the hobby are gone it seems.
Wait... Is this THE Bill Brown from flyover country USA?
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Bil Brown
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Re: Drum Brake Wheel Cylinder Evaluation

#26 Post by Bil Brown »

Yeah Pat.....Nebraska.......I think we first met at the third Reg Holiday in Indy.....right?.......you were in your Speedster......I`ve got paper pics of that event! I was selling the sleeved cylinders cheaper than new ones.
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Steve Proctor
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Re: Drum Brake Wheel Cylinder Evaluation

#27 Post by Steve Proctor »

Many years ago, I had the slave cylinders in my Continental coupe rebuilt by White Post Restorations and was happy with the result. They still provide that service.

https://whitepost.com/brake-sleeving-re ... -services/
STP
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Bil Brown
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Re: Drum Brake Wheel Cylinder Evaluation

#28 Post by Bil Brown »

Steve......do they still sleeve using brass?
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Steve Proctor
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Re: Drum Brake Wheel Cylinder Evaluation

#29 Post by Steve Proctor »

From their website.
Attachments
Brakes.jpg
STP
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Bil Brown
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Re: Drum Brake Wheel Cylinder Evaluation

#30 Post by Bil Brown »

Thanks
Bill Brown

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