Drum Brake Wheel Cylinder Evaluation
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Re: Drum Brake Wheel Cylinder Evaluation
Aren't we talking about wheel cylinders ?; how did we get into master cylinders ?
- Patrick Ertel
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Re: Drum Brake Wheel Cylinder Evaluation
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.
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.
Patrick Ertel
- Jim Liberty
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Re: Drum Brake Wheel Cylinder Evaluation
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.
Jim Liberty
- Harlan Halsey
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Re: Drum Brake Wheel Cylinder Evaluation
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.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.
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.
- Vic Skirmants
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Re: Drum Brake Wheel Cylinder Evaluation
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.
- Patrick Ertel
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Re: Drum Brake Wheel Cylinder Evaluation
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.
Patrick Ertel
- Bil Brown
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Re: Drum Brake Wheel Cylinder Evaluation
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!
Bill Brown
- Martin Benade
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Re: Drum Brake Wheel Cylinder Evaluation
That’s a lot of cylinders without broken bleeders! Must not be from northeastern Ohio.
Cleveland Ohio
62 Cabriolet
56 VW
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62 Cabriolet
56 VW
02 IS 300
04 Sienna
- Bil Brown
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Re: Drum Brake Wheel Cylinder Evaluation
We had a lot of broken bleeders, but my machinist Harry, had no problem getting them out.....HEAT did it..........he was good!
Bill Brown
- Patrick Ertel
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Re: Drum Brake Wheel Cylinder Evaluation
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.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!
Wait... Is this THE Bill Brown from flyover country USA?
Patrick Ertel
- Bil Brown
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Re: Drum Brake Wheel Cylinder Evaluation
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.
Bill Brown
- Steve Proctor
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Re: Drum Brake Wheel Cylinder Evaluation
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/
https://whitepost.com/brake-sleeving-re ... -services/
STP
Steve Proctor
Member Since 1977
VIN 84757
Steve Proctor
Member Since 1977
VIN 84757
- Bil Brown
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- Steve Proctor
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Re: Drum Brake Wheel Cylinder Evaluation
From their website.
STP
Steve Proctor
Member Since 1977
VIN 84757
Steve Proctor
Member Since 1977
VIN 84757
- Bil Brown
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