Lotus Europa Forums > Garage
Brake Master Question
Bryan Boyle:
--- Quote from: EuropaTC on Wednesday,April 24, 2024, 01:33:42 PM ---Hi Bryan,
I had the Spitfire 0.7 dual circuit m/cyl on my car for a while at one point and there are a several guides on how to do it on the forum.
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I know...just refreshing the discussion since it's getting towards spring up here in the northern climes, and pretty sure, besides myself, folks are looking at recommissioning their rides for the season (though, to be honest, I've had mine out more than once considering the lack of winter weather here in MA last winter...)
--- Quote ---When I did mine I removed the wedge shape reservoir and replaced it with a remote one from a Land Rover. Apart from having a greater capacity and being easier to see, it also came with a low fluid warning switch. Anyway, the 0.7" cylinder is ok with non-servoed standard brakes so you know that one will work. I no longer have that on my car but I do have one on the Elan, again without servo assistance but with the larger piston P16 calipers and it's fine.
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I like the idea of remote reservoirs; only question is the fittings on the MC end to accept the hose from the reservoir in place of the attached piece. Don't necessarily want to get into fabrication of hose fittings and such...any guidance there, sir? That it has a low level indicator is a plus...take the place of the removed PDWV. Always thinking, right?
--- Quote ---If you are currently using the OEM Lotus m/cylinder, am I correct in thinking the later Specials had a larger bore to handle a larger rear brake cylinder ? If so, you might not like the additional travel with a 0.7" bore or at least it will take some getting used to. But the big plus is that it's a well trodden path, bolts straight into the chassis and so there's no real surprises in store.
Brian
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The question of travel is one to consider. In looking again at the S2 MC, it's well rusted...and thinking it may be past freeing up the piston and returning it to service. Additionally, the top attach fitting is a captured nut...so wondering if that will be a problem...but probably not, because IIRC, both of the studs are the same size/pitch.
EuropaTC:
--- Quote from: Bryan Boyle on Wednesday,April 24, 2024, 04:57:21 PM ---I like the idea of remote reservoirs; only question is the fittings on the MC end to accept the hose from the reservoir in place of the attached piece. Don't necessarily want to get into fabrication of hose fittings and such...any guidance there, sir? That it has a low level indicator is a plus...take the place of the removed PDWV. Always thinking, right?
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It's not that difficult to fit a remote with the Spitfire m/cyl. The wedge reservoir pushes into 2 rubber grommets in the body so it just pulls off. You can buy plastic or metal fittings in 45,90 & 180 deg angles and all you need is to match the OD on what you buy to the OD of the reservoir. I bought mine from Ebay when I did my conversions and I picked 90deg and although it's no longer on the Europa, it is on the Elan.
The remote reservoir is debatable on the Europa but a real plus on the Elan because it's hidden away beneath the carbs and a PITA to monitor/fill when bleeding. The second image gives you an idea of the fittings & why it's a good idea.
What is handy is the remote level switch. I wired the Europa up to a warning light I fitted in the place of a blanking plug in the centre of the dash. It's a simple circuit and doesn't do a self test when you switch on as modern cars do, if you want to know if it's working you just press down on the switch ;). For the Elan, with no spare lamps, I wired it into the handbrake warning light. If the handbrake is on, the lamp is on. Release the brake and it goes off but if the level is low the lamp still gets a ground so stays on. A more elegant solution with no visible mods to the car other than wiring.
--- Quote from: Bryan Boyle on Wednesday,April 24, 2024, 04:57:21 PM ---The question of travel is one to consider. In looking again at the S2 MC, it's well rusted...and thinking it may be past freeing up the piston and returning it to service. Additionally, the top attach fitting is a captured nut...so wondering if that will be a problem...but probably not, because IIRC, both of the studs are the same size/pitch.
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I'm guessing if you're going to recommission an old m/cyl you'd end up getting it sleeved, which may or may not end up losing the stepped bore. Personally I don't think the stepped bore is a big deal so it wouldn't worry me, but then again there's loads of modern options if you decide a single bore diameter is ok.
Being a geek I actually calculated the pedal travel and can tell you that mine, with rear discs, came in at 3.8cm and I measured between 3.5 & 4cm, the differences all down to me and grovelling down that footwell. Now part of that calc is down to the leverage ratios on the pedal, something that you can modify on the Europa but is limited by the angle of the actuating rod and being so cramped down there. The Elan, even with bigger dia. front pistons, had less travel - down to the leverage ratios - and it feels "better".
But when I fitted larger bore rear calipers to the Europa, it made the difference between the cars more noticable. The calcs said "don't worry", but we humans can be funny creatures and I didn't like it. Anyway, the 0.75 m/cyl I have now gives only a 6mm reduction in travel but for some reason it feels more secure. I wouldn't have thought it based on the numbers but apparently my foot and self-preservation instincts can tell the difference !
Brian
Clifton:
I'm not running stock anything to compare but I know a larger MC bore will give less travel and less desirable feel. I run a 5/8 front and re drilled the brake arm to get a better pedal ratio. A little more travel gives better feel and modulation.
Bainford:
--- Quote from: EuropaTC on Wednesday,April 24, 2024, 10:36:43 PM ---
The remote reservoir is debatable on the Europa but a real plus on the Elan because it's hidden away beneath the carbs and a PITA to monitor/fill when bleeding.
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I have toyed with the idea of fitting a remote reservoir on my Europa simply to raise the reservoir and provide improved head pressure for maintenance, bleeding, etc. As it is now, the height of the OEM reservoir can't be much higher then the bleeders on the front calipers. I will eventually tackle a complete brake service project (all new lines, other mods, etc) and considering the remote reservoir for that reason alone.
EuropaTC:
--- Quote from: Bainford on Friday,April 26, 2024, 10:38:39 AM ---I have toyed with the idea of fitting a remote reservoir on my Europa simply to raise the reservoir and provide improved head pressure for maintenance, bleeding, etc. As it is now, the height of the OEM reservoir can't be much higher then the bleeders on the front calipers. I will eventually tackle a complete brake service project (all new lines, other mods, etc) and considering the remote reservoir for that reason alone.
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It is a strange one, the remote reservoir was standard on the UK single circuit brakes and honestly there's no great effort to fit a remote to a tandem m/cyl. I can only think that when Lotus moved to dual circuits for the Federal cars they decided it was cheaper to leave the tandem cylinder as it came and save on the production line costs for a remote + pipework.
Having said that, the single circuit m/cyl is much easier to fit a remote to, the reservoir connection is threaded so it's easy to fit a feed pipe.
When I was researching braking systems I found several references to the advantage of having a head of fluid above the tops of the calipers/drums. So yep, if you're refreshing the whole system I'd say it's a good idea, plus of course it's much easier to fill and monitor.
Brian
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