[Heybuck]

Thanks for all the replies. Yes, I was wrong in that I did miss the page in the '66 shop manual which gto4ben correctly stated that it should have a 7/8th bore but I'm GLAD I missed it because I might have agreed with my parts supplier when he said his books say 7/8th".

My new (made in Taiwan!!!) Raybestos master cylinder with a 1" bore has arrived and will have to wait till my booster is rebuilt before I can fit it up.

I just received the latest AMES catalogue and it doesn't actually list a new master cylinder for a 1966 car with Power Brakes? Nor does it specify the bore diameter.
And also it does not specify the bore diameter for the 1966 rebuild kit (PR201DK).

I'll write to AMES and ask some questions in the hope it might get some clarity.

All this is indeed very confusing I agree.

[mgarblik]

Originally Posted by Heybuck

Thanks for all the replies. Yes, I was wrong in that I did miss the page in the '66 shop manual which gto4ben correctly stated that it should have a 7/8th bore but I'm GLAD I missed it because I might have agreed with my parts supplier when he said his books say 7/8th".

My new (made in Taiwan!!!) Raybestos master cylinder with a 1" bore has arrived and will have to wait till my booster is rebuilt before I can fit it up.

I just received the latest AMES catalogue and it doesn't actually list a new master cylinder for a 1966 car with Power Brakes? Nor does it specify the bore diameter.
And also it does not specify the bore diameter for the 1966 rebuild kit (PR201DK).

I'll write to AMES and ask some questions in the hope it might get some clarity.

All this is indeed very confusing I agree.

My NEW 1" MC I installed from NAPA was made in Taiwan as well. Probably the same manufacturer. That's the one that had the machining issue in the piston. So pay particular attention to that when fitting it to the booster.

[Scarebird]

This is what rockauto says about it - usually with manual masters the smaller bore is for HD shoes, but the opposite may hold here...

[Scarebird]

Originally Posted by mgarblik

My NEW 1" MC I installed from NAPA was made in Taiwan as well. Probably the same manufacturer. That's the one that had the machining issue in the piston. So pay particular attention to that when fitting it to the booster.

All masters, especially those from applications that are infrequent sellers should always be disassembled/inspected on the bench and relubed with fresh brake fluid.

[Heybuck]

My new MC is in a Raybestos box and is numbered MC36006
I was under the impression that Raybestos is an American company and my MC would be American made but I guess these are the times we are living in.

I’ll take on board the advice to disassemble and check before it’s installed.

But, all this is seriously leading me to the conclusion I should have just spent the extra and had my original sleeved and rebuilt. I may well decide to go that route. The people here who do this work are “old school”, with a strong reputation for highest quality work.

Thanks all.
Ian