Lotus Europa Forums > Technical Articles and DIY tools and tips
Thoughts on TCS Brakes
Exlimey:
Another thought,if you are doing a complete system rebuild,personally I would switch to silicone fluid.
Bryan Boyle:
--- Quote from: EuropaTC on Monday,March 07, 2022, 11:01:42 PM ---Hi Bryan,
If you're after a very simple system, then despite the safety aspects a single circuit is the way to go. Yes, I know that's controversial and it's coming from someone who converted his single circuit UK car to dual circuit, but if your aim is for simplicity then single circuit with no servo assistance is the one.
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It's a thought...and an option...albeit not the preferred, but an option.
--- Quote ---From hazy memories servo assistance was accompanied by harder front brake pads, or at least it was on the Elans so I can't see why the Europa would be different. I can remember the servo failing on the Elan in the early years and finding it very unnerving with the high pressure required to stop. The point here being that the servo/boosters were there for a reason & not just a marketing tag line, it was a deliberate design/spec change.
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Agreed; change one variable, now you're going down the road of looking further downstream at the subsequent effects that are needed to be addressed.
--- Quote --- These days we're spoilt for choice on pad materials so removing the servo/boosters isn't such a big deal, you can easily find a pad that will restore the cold braking bite for road driving. The other point has already been made by Clifton, the pedal leverage ratio is high on the Europa compared with other cars (4.3 ?) hence the assistance reduces the need for gym work on the legs.....
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For normal road use on the previous rides, I never really thought the effort was out of line or excessive. Maybe that was just me, but your point about the pad materials (from stock to greenstuff to ???) available can offset changes made upstream to give suitable performance. It is not that (at least the calipers/disk assemblies) are bespoke to the Europa...so it's possible, I think, to strike a decent balance. And besides...you can change pads in a half hour of wrench time if need be...
--- Quote ---I ran my TC with a single 0.75" m/c (0.7" OEM) standard brakes & servo until 2014 when I replaced it with the Spitfire 0.7" dual circuit m/c, no servo/booster. It worked and I've no doubt that you'd find the same although you'd have fractionally more travel than I had. The other snag is that it was designed to be mounted at an angle so either you accept a lower reservoir volume, change the reservoir or plumb in a remote one. A remote makes filling much easier and you can easily get one with a low fluid warning cap.
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I've not seen a remote reservoir for the Girling style cylinder. Interesting. I like the idea considering where the cylinder is hidden...nice to glance at the reservoir and see if you're up to level than taking a cap off and looking down...
--- Quote ---In terms of feel, it was ok, no drama but then again I was running Greenstuff pads, designed for similar applications.
So while I'd personally junk servo assistance I think you'll need to address more than just the m/c selection. If you have the genuine Lotus pads designed for boosters then that's the first change. If you still don't like the pedal weight then you can make minor changes to increase the pedal ratio - more travel, less effort.
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That's the fun part of this project: resurrecting an ignored (and somewhat fiddled with) ride and coming out the other side with a lot of "patina" but a smile.
--- Quote ---I'd suggest you step back and ask what you really want, is this a one-off mod or will you be bitten by the bug and it's just the start ? Many on here have custom brake systems, usually discs all round with both servo/non-servo options so there's a well trodden path to follow either from a bolt on kit or making your own. And if a rear disc conversion is in your future then you might end up wanting to change the m/c again for optimal braking depending on where you go to. For example my 0.7" spitfire m/c ended up as a 19mm (approx 0.75") m/c when I changed calipers & discs.
Brian
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This is a one-off, Brian, to 1) simplify the operation (while sacrificing as few capabilities as possible, acknowledging that any deviation will have downstream effects that will have to be dealt with) and 2) simplify the maintenance as the end game.
Appreciate your insights and will take them into serious consideration.
Bryan Boyle:
--- Quote from: Exlimey on Tuesday,March 08, 2022, 04:32:57 AM ---Another thought,if you are doing a complete system rebuild,personally I would switch to silicone fluid.
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Certainly an option, considering I may end up opening up the whole system, rebuilding calipers and replacing rear cylinders, and replumbing. Would get away from all the minuses of the traditional Castrol LMA mineral fluid, right?
BDA:
Re: brake fluid
I understand the choice of silicone brake fluid. It has a high boiling point and a low moisture affinity. Those are handy characteristics for a street car but there are negatives that should be considered. The main one is that there should be NO glycol fluid in a silicone system which means rebuilding and thoroughly cleaning all brake components and lines.
As I mentioned, the boiling point of silicone fluid is a main advantage but modern DOT 5.1 fluids have both a higher "dry" and "wet" boiling point. of course, silicone's lack of moisture affinity would seemingly eliminate any worry about wet boiling points. Silicone fluids can be difficult to bleed and can give a spongy pedal because of some compressibility when hot.
There is certainly more to his story. A lot of people swear by silicone fluid. I think it would probably pay you to investigate all the different advantages and disadvantages of each type of fluid. I found this article informative (https://www.engineerine.com/2022/01/dot-3-vs-dot-4-vs-dot-5-vs-dot-51-brake.html).
EuropaTC:
--- Quote from: Bryan Boyle on Tuesday,March 08, 2022, 08:44:21 AM ---I've not seen a remote reservoir for the Girling style cylinder. Interesting. I like the idea considering where the cylinder is hidden...nice to glance at the reservoir and see if you're up to level than taking a cap off and looking down...
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A remote reservoir was standard on the single circuit UK cars. When I converted to dual I just bought a 2 compartment reservoir which came complete with a low level switch & located it in the same place as the original one. I think it was a Land Rover part and only needed wiring into a warning light.
It's a very handy & simple mod, no leaning over into the depths of the front chamber to see if there's any fluid left ;)
Brian
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