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Type -3 rear drum brake Question?

FM Former Member
I have removed the disc brakes from the rear of the D and we are up to our ears in the middle. Of the wider front Beam & rack upgrades I have a Question On the wheel cylinder size for the rear drums .

Two sizes are a direct fit to the type 3 backing plates type 3 and super beetle front
. The rest would have to be mounted upside down for the bleaders to be in the right place. And require som trimming of the bolt flange,to clear the bearing caps.

Sizes avalible for my aplication to the T-3 Drums are.

15mm 1968 rear All beetle and supers (Mounted Upside Down)
17mm 1967 rear beetle MUD
20mm 1970 rear Type 3 Mounted correct ----FACTORY----
22mm Superbeetle All front Mounted correct.

We have tried it with the Type 3s and have excellent back brakes but no front. The front Disc refuse to blead. It could be a fault Mastercylinder.
Im wondering if the rear wheel cylinders are using up to much of the petal travel .Which Is Unlikely Due to we can only get half a petal during bleads

We allready have the smallest correct mounting cylinders in place. My best guess If I made any changes at all would be to use the upsidedown mountd 1968 rear beetle wheel clyinders

Please note the rear brakes feel and lockup fine now.we just cant get the front to work.

But I wanted to throw this into the fourm. to get feedback and maybe some insight.

My first guess is simply a bad master cylinder that has been rebuilt this week. due to it leaking into the floor just a little for the last year. We have a new one But it was getting late and i said to hold up and let me ask some freinds.
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FM Former Member
I have removed the disc brakes from the rear of the D and we are up to our ears in the middle. Of the wider front Beam & rack upgrades I have a Question On the wheel cylinder size for the rear drums .

Two sizes are a direct fit to the type 3 backing plates type 3 and super beetle front
. The rest would have to be mounted upside down for the bleaders to be in the right place. And require som trimming of the bolt flange,to clear the bearing caps.

Sizes avalible for my aplication to the T-3 Drums are.

15mm 1968 rear All beetle and supers (Mounted Upside Down)
17mm 1967 rear beetle MUD
20mm 1970 rear Type 3 Mounted correct ----FACTORY----
22mm Superbeetle All front Mounted correct.

We have tried it with the Type 3s and have excellent back brakes but no front. The front Disc refuse to blead. It could be a fault Mastercylinder.
Im wondering if the rear wheel cylinders are using up to much of the petal travel .Which Is Unlikely Due to we can only get half a petal during bleads

We allready have the smallest correct mounting cylinders in place. My best guess If I made any changes at all would be to use the upsidedown mountd 1968 rear beetle wheel clyinders

Please note the rear brakes feel and lockup fine now.we just cant get the front to work.

But I wanted to throw this into the fourm. to get feedback and maybe some insight.

My first guess is simply a bad master cylinder that has been rebuilt this week. due to it leaking into the floor just a little for the last year. We have a new one But it was getting late and i said to hold up and let me ask some freinds.
Gordon NicholsGordon NicholsMassachusetts 1993 CMC Supporting Member

Are you running a two-circuit master cylinder? You know: one circuit for the rear (both wheels off of one line) and then two separate lines for the front (left and right) off of the same piston or do you have one of those early, single-circuit MC's (one line for everything)?

If it's a dual, then I would pull it, bench prime it and re-install to see if that cures it. If you have a pressure-bleeder, then that should work without bench priming it if you run a robust flow rate through the lines.

If it's a single-circuit, then I would think you've got a massive air lock between the MC and the "T" going to the wheels.
FM Former Member
We pressure blead the heck out of it. everything is 1970 year parts, Duel circut.

I think the rebuild kit was faulty.it was in a very old box.

I was reluctant to do that anyway . but he likes orignal parts.

Itold him If the New one he has on the shelf doesnt work order another one. they can be bad right out of the box too...

That was late Saterday nite. He did not call this evening.


What about the rear wheel clyinders do you think ,,I should reduce them back to 17 mm if the rear brakes are to touchy because of the bigger wider drums? or stick with the 20 mm. T-3s?
Gordon NicholsGordon NicholsMassachusetts 1993 CMC Supporting Member
Stick with the T-3's....

I doubt that they'll give you any troubles.

Besides, 80% of your braking power will be up front, anyway...

I've given up on rebuilding master cylinders, especially with 15-20 year old rebuild kits. Just isn't worth the effort, cuz over half the time the rebuild leaks worse than what I started with because the seals are too dry to activate them. Ditto for some of the "new" MC's off the shelf (especially the Asian ones). I put in a "quality" Asian one 1-1/2 years ago, and it lasted two seasons (and wasn't especially good when it was "new", either). Finally sprung for a new German one at a 30% premium and it's been OK since install (last Spring).

Good parts are gettin' harder to find.....

gn
FM Former Member
Mr Vestal found a FTE and now they work fine. thats cured for now ,

I have been reporting a probem here with the front wheel bearings over the last three years . and as we were dismantling the front Beam we found out exzactly why. The front disc brake kit was shipped with the wrong inner wheel bearings from CB-P and when I replaced the front bearing last year I also used the wrong bearings.

I didn't catch it eather

After some part number checking. Disc brake spindles are ALL a 1967 0r 1968 Part nummber with a smaller inner boss for the bearing races to set on. The tie rod end hole is smaller also ,but we had a reamer for that I've been useing 1970 Vw beetle inner bearings which fit lose,per the model yesr of my pan based car .

Not dangerious but very agravating. But In any case the beam is NOW on the car and i will have to replace the fuel tank to have clearance for the steering shaft we tried to massauge the old tank and it tore a pinhole almost on the last strike of the plastic hammer.

Im not going to fill it with water and atempt to brase it.

NOPE not me.

So I ordered a new 16 gallion tank that I will still have to hammer and maybe If my luck gets better Wont need to brase again But at least it wont or can't go BOOM! If I have to.

I will make a note of this to the sulpplier when I order. a unused tank
FM Former Member
I cheated and used Duplicolor from a Autozone. But I would have preferred Morton 2 part epoxy it has a tough rubbery texture when set. and realy holds up to road debre and the gravel from the driveway.

i cut my cost the Morton kit is over $100.oo. 2 cans of duplicacolor $12.oo
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