In search of the best 5/8" tandem brake master cylinder

[Sea Ranch]

Greetings,

I've exchanged mail with some members and been reading the forum and other places . . .

Still haven't found precise info on a suitable 5/8" bore tandem brake master cylinder for my Plus 2S, which I operate without vacuum boosters.

I currently have a Lucas branded tandem with .7" bore and while it functions fine, the pedal effort is higher than I want. And I do not want to install vacuum boosters. I believe a 5/8" bore master cylinder might be just right.

So . . . if anyone has installed such a M/C successfully AND can identify the exact part, etc., I would love to hear about it. And I think many others would as well

(I've also toyed with the idea of sleeving my present master cylinder and boring/honing to 5/8", but where to find the suitable piston and seal set, I don't know . . . )

Thanks!

Randy

[KevJ+2]

Hi Randy,
I've fitted new Wilwood 5/8 masters to both brakes and clutch. They are a direct replacement fit for the Girlings. The only thing I did was to keep the pushrods (and the clutch spacer). Sorry Randy, just re-read your post and you say tandem master and mine is single, so may be of no use
Like you, I have done away with the booster / servo and although I have not yet driven it, the brake 'feel' is good.
HTHs
All the best, Kev.

http://www.wilwood.com/MasterCylinders/ ... nding.aspx

[Sea Ranch]

Yeah, thanks, Kev. I did note your comment on the Wilwoods earlier.

Are you not concerned about a single circuit braking system? Apparently 1966 was when these were banned in North America.

The Girling 5/8" master is available and nice for the clutch. Built in reservoir is too small for brake, but the Wilwoods solve that problem. Only wishing for the right tandem part now.

[KevJ+2]

Randy, I did give some thought to the tandem system, but I've renewed the whole system with kunifer pipes, armoured flexible hoses new pistons and seals and the master, of course. I'm not overly concerned, but ask me again in a couple of years and I might answer differently
Kev.

[Sea Ranch]

Yeah, I get that; I really do. It's how it used to be done, plus better materials, etc. Should be safe.

I see that some of the higher end brake specialist shops state emphatically that if a person replaces the fluid in the system every year, the parts may last a lifetime. It's the water in the fluid that leads to breakdown of metals, etc. And from what I read, DOT 5 silicone fluid is not the answer, as it does not prevent water from getting it; just does not absorb it.

Anyway, carry on, Kev . . .

Randy

[StressCraxx]

Have you considered the Tilton model 74 dual circuit master?

[Sea Ranch]

Thanks, Dan. I had not.

Just went to their website. Obviously a great company and products.

I don't see tandem cylinders, presumably because they are race specialists and expect users to go dual masters for a dual circuit braking system.

I am hoping to stay as stock-like as possible, and use a tandem master, so everything works with existing pedal box, etc.

How's the weather down there?

Randy

[snowyelan]

Hi Dan,

Was curious about the tiltons mentioned above so I looked them up. I have a single circuit master that needs replacing, but for what it costs for a decent single unit vs these I might just switch. 2.25" mounting pattern, not sure what the original is but it sounds close...

http://www.jegs.com/p/Tilton/Tilton-74- ... 5/10002/-1

Just realized that they aren't dual circuit, so nevermind......

[Sea Ranch]

That's what I'm seeing on that site, too.

I'm assuming that Tilton's (and most racer's) solution to a dual circuit braking system is dual masters, run side by side, with a "balance bar" so the pedal mechanism works both cylinder actuation rods.

On the other hand, most factory dual circuit braking systems are fed with a tandem master cylinder (single master with two circuits, end to end in the same bore).

[stugilmour]

Randy, I had resisted replying as my suggestion is so vague; I figured others would have a source for the specific item you require.

Did you ask Ray at RD yet? I thought he had a replacement dual circuit master available a while ago, but I could be dreaming! IIRC it was a direct swap except the threaded discharge ports were on the opposite side from stock, so some repiping required. If one is doing total restoration this may be be a big deal. I cannot recall the cylinder diameter though.

Thinking about it, if Ray was only offering a close to original replacement, it probably indicates there isn't much out there?

As mentioned, I understand it is critical to save your piston rod to swap in to whatever is available?

Did you get your rear bearings sorted? I forgot about getting the hub tool for you; the chap in Edmonton was going to look for it but I haven't heard back. I should give him a call again anyway to see if he located it.

Won't be down to ABFM this year unfortunately.

Stu

[Sea Ranch]

Randy, I had resisted replying as my suggestion is so vague; I figured others would have a source for the specific item you require.

I still live in hope

Did you ask Ray at RD yet? I thought he had a replacement dual circuit master available a while ago, but I could be dreaming! IIRC it was a direct swap except the threaded discharge ports were on the opposite side from stock, so some repiping required. If one is doing total restoration this may be be a big deal. I cannot recall the cylinder diameter though.
Thinking about it, if Ray was only offering a close to original replacement, it probably indicates there isn't much out there?

I will definitely call Ray. Talked to Ken at Dave Bean yesterday. He's thinking I won't find a British 5/8" bore tandem. I think it will end up being Japanese, as several have said Nissan/Datsun made them in the '70s, though I don't yet have a part number.

As mentioned, I understand it is critical to save your piston rod to swap in to whatever is available?

I see. You mean that the "rebuild kits" don't have the metal; only the rubber bits? Hmmm . . .

Did you get your rear bearings sorted? I forgot about getting the hub tool for you; the chap in Edmonton was going to look for it but I haven't heard back. I should give him a call again anyway to see if he located it.

Yes. All done. Used correctly threaded plates from the BC Lotus club, along with a large Proto puller from my school's shop, and got the job done Many thanks for your thoughts and efforts. Basically, everything is apart (including electric motors, etc ), except motor/gearbox/diff. Waiting till fall for those. Gearing up now for "spraying season"

Won't be down to ABFM this year unfortunately.
Stu

Will look forward to seeing that Esprit some day. Went to the Western Washington Abfm this past year. Nice. Not quite like the Vancouer Van Dusen meet, though. Hope you will be down with your Plus 2 in 2018; that's the planned roll-out for mine.

Best regards,
Randy

[StressCraxx]

Thanks, Dan. I had not.

Just went to their website. Obviously a great company and products.

I don't see tandem cylinders, presumably because they are race specialists and expect users to go dual masters for a dual circuit braking system.

I am hoping to stay as stock-like as possible, and use a tandem master, so everything works with existing pedal box, etc.

How's the weather down there?

Randy

Hello Randy,

My apologies. Sorry to lead you astray. I thought that was a dual circuit master.

[cabc26b]

Randy ,

When I went looking I could only find 3/4 inch bores - I sourced two , one from Raybestos and one from Nabco . I used the Raybestos because it had better port orientation a LHD ?lan -

If you have interest I can go look up the part numbers -

PS - This is not a good as a dual master set up - but tandem can fit fitted with small effort and reverted with out a trace .

[prezoom]

The closest I could find, was a Datsun 1200/Sunny/B110, at 11/16".

[snowyelan]

I found this 5/8 bore from Willwood, would need an adapter bracket to the firewall and reservoirs but at least its a current item....maybe...no rebuild kits listed.

http://www.wilwood.com/MasterCylinders/ ... =260-11097