68-70 master cylinder conversion

[cdennisg]

I am looking at a 68 bus that will need all new brakes. The 68 master cylinders are quite expensive, but not unobtanium. The 70 M/C is much cheaper and appears to only differ in that is uses only two brake line ports. On the 68 each front brake has it's own port from the M/C. Would it be safe to plumb both of the front hoses into a T fitting (as is done on the 70) and then run a single line down to the '70 M/C? It appears as though everything else is the same. Is the spacing of the reservoir holes the same?

This bus is being pulled from it's long-time resting place and put back on the road, in a day. I am bringing all new brakes and wheel bearings, and all other necessary parts to drive it 700 miles home. My friend Eric (long-roofs on here) is coming with me to pull home a 71 from the same place. I have a 68 M/C and a NOS rebuild kit in my parts pile, but there is some pitting in the bore out near the end. It is in the dust seal area of the plunger, not the pressure area, so it could be used. I just want to make sure I have good brakes and I will do what I can to make it safely home.

Looking into all options. Does anyone have experience with this later M/C conversion into a 68 bus?
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[germansupplyscott]

there are some differences in the electrical connections also, but they may not be a deal-breaker.

the casting for both those masters (021Q and T) is the same. i have a new ATE of each of them in front of me. they are both 22mm bore, so i think your idea might work.
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SL

[cdennisg]

Thanks. I knew about the brake light wiring issue, but it should not be difficult to make it work.

Ever heard of this being done? I can't be the first, what with all the money saving shortcuts that have been done to VWs over the years. What are your feelings on using my original M/C with the pitting out near the end? Am I correct in thinking that the very outer cup is more or less a dust seal? It will be the only one riding where the pits are.

For all I know the M/C in the bus may be usable/rebuildable. I just want to make sure I can get the bus out of there, since parts availability in the area is almost nil.
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[germansupplyscott]

my first choice is always to use original parts. whether that means reconditioning the pitted MC or getting a new correct one, i would always try to find and use the correct original part, especially if the vehicle is a keeper.

but if you were to use an ATE brand master for a '70 you might discover something that can work well and save some cash. the difference however is not that great for similar quality parts. i think in our case for instance the 68-69 master is 73.00 more than the '70 MC, both made by ATE. so it's not like the savings is going to make or break you.
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SL

[cdennisg]

Indeed, the price difference isn't great, but $73 is $73. That will pay for the gas to get this bus home.

Thanks for your input, it is much appreciated.
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