[T3] Rear Wheel Cylinders

[Jim Adney]

On 19 Apr 2011 at 21:45, Brent Bottolfson wrote:

> I want to replace my rear wheel cylinders while I'm doing the rear 
> brakes.  I have a 69 Fastback with 4 lug rear drums.
> 
> Are all 22mm wheel cylinders the same?  I can find good 22mm German ones 
> for a beetle, but the 361 part number wheel cylinders for a Type 3 seem 
> a bit harder to find.

I believe the Type 3 ones are slightly different in length. I actually 
recommend that you simply rebuild the ones you have. Do it ON THE CAR and it 
will be MUCH easier than replacing them. Buy a brake cylinder hone and do them 
in place. Clean up the old parts, which are almost always fine, and you've 
saved time, money, and hassle.

I only remove them if the bleed valves are broken and need to be replaced. For 
that I have to take them off so I can torch them to free up the stump. The 
problem with removing them is 2-fold: If you're not careful you will damage the 
rubber boots, and you are VERY likely to destroy the hard line feeding into 
them.

If you want the maximum in long term service, lube them with some Dow-Corning 
#33 silicone grease and use DoT-5 silicone brake fluid when you're done. I have 
a faq on the DoT-5 if you're interested.

If you find that you need replacements, I have good rebuilt OG Type 3 
cylinders, as well as rebuild kits. I have LOTs of these, but I've never had to 
use one myself.

FYI, the cylinders are actually 7/8" (22.2 mm.) For some reason, master 
cylinders and wheel cylinders, at least in our era, were all in inch 
dimensions, while disk caliper bores were metric (except in the US, where they 
were also in inches.)  

-- 
Jim Adney
jadney at vwtype3.org
Madison, WI USA