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Thu Mar 15, 2012 10:07 am

I have read many times that swapping the front wheel cylinders with the rear wheel cylinders will help improve brake bias when running big & little tire combos. In one post, it was said to use the 17mm cylinders in the front, and the 22mm cylinders in the back. I am ready to start installing the brake system on my short chassis, and need help deciding which cylinders to buy based on the year of make for the parts.
The chassis is based on a 1963 T1 pan that has been converted to IRS. Can someone please let me know what they would buy based on the info below? For example, "Use the 1958-1964 cylinders on the rear, and use the 1968-1979 rear cylinders on the front". I may have already answered my own question, but I just dont know if these cylinders all fit interchangeably from front to back, with diiferent years of brake shoes, etc.

FRONT WHEEL CYLINDER, 1958-1964
FRONT WHEEL CYLINDER, 1965-1977, std beetle

REAR WHEEL CYLINDER, 1958-1964
REAR WHEEL CYLINDER, 1965-1967
REAR WHEEL CYLINDER, 1968-1979

These examples were taken from the W.West website.
Thanks for any assistance, guys.

Thu Mar 15, 2012 10:21 am

I just rebuilt the rear brakes on my rear swing axle, I got 23 mm super beetle front wheel cylinders for the rear as recommedned by BL3Manx...

http://www.rockauto.com/catalog/raframecatalog.php?carcode=1409352&parttype=1952

Thu Mar 15, 2012 2:27 pm

I don't "swap" wheel cylinders. On my street legal Dunebuggy I use front wheel cylinders on all 4 wheels to give 50/50 braking. I feel it is wrong to swap wheel cylinders and have more rear braking bias then the fronts. My buggy always stops straight under hard breaking.

If your using an early single reservoir master cylinder then use 4 early front wheel cylinders. If your using a late dual reservoir M/C then use 4 late front wheel cylinders. For absolute saftey you really should be using a late dual M/C anyway.

Thu Mar 15, 2012 3:26 pm

pallen wrote: I just rebuilt the rear brakes on my rear swing axle, I got 23 mm super beetle front wheel cylinders

I believe they're actually 23.8mm. You can check my math but that means they have 17% more area and apply 17% more braking force than 22mm front wheel cylinders.

The question of whether or not you want smaller than stock front wheel cylinders on a fiberglass buggy I think is probably subject to the variables(weight distribution, wheel base, tire area) of your buggy. You're looking for a ratio between the front and rear which takes in the factors of axle weight and tire contact patch and achieves maximum braking force and avoids having one axle skid significantly before the other. Typically on a fiberglass buggy that means putting as big as possible wheel cylinders in back. If you put them in back and the fronts still lock up before the rear, well then you can't go any bigger in back(unless you go to even bigger drums like Type 3) so then you have to go to smaller wheel cylinders in front.

However if you go to the Super Beetle front wheel cylinders in back and still have stock wheel cylinders in front and neither axle locks up significantly prior to the other during maximum braking, then you're good.

FWIW, if you're looking for the most powerful VW drums you can put on a fiberglass buggy, its Type 3 rears.

Thu Mar 15, 2012 5:18 pm

Quote: FWIW, if you're looking for the most powerful VW drums you can put on a fiberglass buggy, its Type 3 rears.

In addition to the larger diameter drum, wider shoe and they have 24 mm slave cylinders in them.