Europa TC Brakes

[Roger]

OK, so this Europa I just bought has ineffective brakes. I expected this, the seller told me so beforehand, but now I'm starting to look at them - I like brakes.
These are VERY squishy, but will "pump up" somewhat. Before I start to bleed them, my next logical move I think, I was wondering if there are any "gotchas" lurking. See, I only have the Europa workshop manual, not the TC, and its different. For a start, this has twin vacuum boosters in the engine bay. Now for some reason, the top one has no vacuum line to it - the line has been deliberately plugged. I don't know yet if that's the front or rear brakes that are unboosted - for that matter I don't know if either booster works properly!
Any hints or tips before I dive in?

 

[RobT]

The boosters are notoriously unreliable - and worse, when they do fail, the vacuume lines to the intake suck all the brake fluid out and you have no brakes at all! Oh - and they cost a small fortune to rebuild.

A common conversion is to bypass the boosters, and install a smaller bore master cylinder (the stock is 0.85, and a common replacement is 0.7 inch). There is a Nissan replacement you can use, or Ray at RD Enterprises sells a Girling unit that drops right in. I recently did this on my TCS, and replaced all the pipes, hoses, rebuilt the calipers etc - I agree, its good to be able to stop!

Other improvements I undertook are larger bore rear slave cylinders (from a Sunbeam I seem to remember - Ray can help there too), higher performance pads (Hawk/Porterfield), and SS hoses. Other mods folks have done (but not me) are larger front disks (GT6 in place of the Spitfire units that are stock) and if you are really keen, there is a rear disk conversion (Miata/MX5 bits I think).

Check out the "Knowledge Base" on Jerry's site (see my earlier post). This is a searchable data base of all the messages posted on the Europa Web Ring. Tons of info. Also the "Documentation" page has lots of info and a PDF of the Europa S1/S2 and TC manuals as well as a detailed description of the Nissan M/C conversion:

https://www.lotus-europa.com/manuals/index.htm

Cheers,

Rob.

 

[Roger]

Many thanks, Rob. I will follow up on your suggestions.

I assume the idea of the smaller MC is to reduce pedal pressure? Someone somewhere else suggested it wasn't too bad with the stock size and no boost. Any comment?

 

[RobT]

Hi Roger.

Yes -- the smaller diameter M/C gives more "leverage" and higher brake system pressure for the same pedal effort (but more pedal travel of course). Going from 0.85 to 0.7 inch dia. increases pressure by about 50% (its an R-squared thing). The brake systems on the S1/2 Europa's were unboosted and had a M/C of about the same (0.7 inch) diamiter I believe. These are very light cars so boosters were probably a bit of an over-kill, but I am not sure if you want to use the original 0.85 size M/C without the boosters - that could make for quite a hard pedal. You could always just plumb it up and see how it feels though. Unboosted with the 0.7 inch M/C the brakes still require a bit of effort - not like a modern car by any means.

Hope that helps.

Rob.

(BTW - how do you like the Elise? How does it compare to the Europa? I've been thinking lately there may be an Elise in my future soon.)

 

[Roger]

I'm told that mine may already have a 0.7 (18mm) Master cylinder and that the 0.85 was for the S only. Who knows the truth? Until I tear it down I won't know, but the concensus advice is to ditch the boosters.

And I love the Elise. It's even less civilised than the Europa (!) and much, much faster of course. But then, I don't really know Europas all that well, it's been several years since I drove one at all seriously.

 

[DrEntropy]

A bit more pedal effort is about all there is to losing the boosters, keeping the original M/C and re-plumbing. Hey, they're LIGHT cars. :laugh:

Please don't be tempted to use compression fittings as couplings on the brake lines in lieu of bending up some new Bundy pipe. :thumbsup:

...and look at all the weight ya can toss over th' side! :wink: