Lotus Europa Community
Lotus Europa Forums => Garage => Topic started by: Steve_Lindford on Friday,October 14, 2016, 09:03:16 AM
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Any advice on this?? English TC with single line system. With the master cylinder in the front but the servo at the back - Im not sure which order to go round the wheels. Someone has already told me I will be wasting my time trying the traditional method of pumping the pedal - as the servo is so high - and that I need to pump it through.
Steve
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With all the twists and turns in the brake lines, it's easy for air to get trapped.
There are pressure bleeders that are good (https://smile.amazon.com/Motive-Products-0100-European-Bleeder/dp/B0002KM5L0/ref=sr_1_1?s=automotive&ie=UTF8&qid=1476461272&sr=1-1&keywords=pressure+bleeder - you get adapters for different M/C openings). You might get away without using a pressure bleeder, but you MUST put a hose on the bleed nipple that goes into a bottle of fluid no matter how you do it. You can get bottles setup for this purpose from car parts stores or Amazon (https://smile.amazon.com/Genesis-GA3075-Cable-Bleeder-Bottle/dp/B000W7F2GI/ref=sr_1_1?s=automotive&ie=UTF8&qid=1476461691&sr=1-1&keywords=brake+bleeder+bottle). Back in the old days, we used a coke bottle and a plastic tube.
When you bleed brakes, the rule is to start at the brake that is farthest away from the M/C. That would be the passenger front, then the driver front, passenger rear, then driver rear.
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So are you calling the servo (booster) the master cylinder?? I have drivers side on the right and passenger on left being in the UK...
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The brake line goes from the M/C to the booster and from there to a five way union and then to the calipers and wheel cylinders. So the path for the front brakes is from the front of the car at the M/C to the rear to the booster and then to the front again to the calipers. That makes the front brakes the furthest away from the M/C so they should be bled first. The passenger's caliper is further from the M/C than the driver's caliper, so that should be the first.
The terms "passenger" and "driver" are relative and translate to UK or US cars.
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OK Got it - thanks...
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Let us know if you have any problems.
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Ive ordered a system that uses pressure from one of the tyres - so will see how that goes. Not sure all Europas had servo in the back - and previous receipts say it is a replacement from an Elan - altho I doubt it will make a difference to what we have been discussing...
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I'm not sure why bleeding the brake furthest from the M/C is better (presumably because of some dynamic at junction points), but it's always been the rule I've heard so I follow the rule.
You're correct that some Europas did not come with boosters. I think TCs did and maybe some S2s. Somebody else here might know or you could check parts manuals, but I suspect that the Elan and Europa shared the same booster. Having or not having a booster doesn't make any difference, the routing of the brake lines is the difference according to the rule.
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Hi there. The booster in the twin cam is smaller than the Elan +2 one, quite significantly. I recently bought a Lockheed replacement and had to swap it. Found the difference after trawling through many Girling-Lockheed equivalent charts...
Bleeding, I would say it probably doesn't matter the order, furthest first but I'd probably try and do 2 laps of the system so any air pushed past a junction that found itself hiding up a previously bled section is removed.
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Here's a link for the single circuit TC brake system.
http://lotus-europa.com/manuals/tcparts/j/ja.htm
Just be careful you don't inadvertently empty out the reservoir with a power bleed system, especially with the smaller reservoirs of the single circuit master cylinders. It's very easy to do, even with the larger, tandem system MCs.
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BDA - When I said - some Europas dont have a servo at the back - I meant that I believe some have them in the front. Here is mine - there is an indication from some old paperwork that it might come from a Plus 2...
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That's an aftermarket Lockheed booster. You can see the mounting holes from the original Girling booster. I'm not familiar enough with Plus 2s to say what boosters they had originally, I suspect all original boosters were Girling units, though.
I'm not aware of any Europas that had a booster in the front. I know TCs pretty well, though I am constantly learning new things about them, I am far less familiar with S2s and S1s. It think I remember many years ago I read about a guy who put a Japanese truck M/C complete with booster on a Europa, I wouldn't trust that memory. As far as original setups go, it seems highly unlikely they would run a vacuum line all the way to the front of the car.
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No booster on an S1.
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Banks sell a front mounted booster for the Europa. They sent me one by mistake when I ordered the twin cylinder pedal assembly
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I bought one of these to bleed the brakes -
http://www.gunson.co.uk/product/G4062/
It uses pressure from tyre to push fluid through. The instructions suggested 10psi - but after reading a review on the internet where someone had fluid spray over the car - I opted for 8psi and covered the car near the master cylinder. It took me 4 attempts in the end - and I got more confident and took the pressure up to 13psi - and also pressed the pedal to assist (which they recommend).
I had quite a few leaks on new joints I had fitted where I was too worried about tightening too much and stripping the threads.
Now on to the handbrake. Does anyone with the traditional brake set up have one that actually works?? Is the only way to get one to pass the British MOT test a bribe?? What I can't understand is how the cable seems to be tight at the rear - but have slop in the tunnel or at the front of the system. Could it be the weight of the long length of cable hanging down?? It seems to me because the pivot part at the front does not rotate from its centre -there is less movement at the brakes than at the handle. If this ratio could be changed there would be some hope of getting a handbrake that works.
I also have a problem with the handbrake ratchet which I haven't sussed out yet. I seem to have to twist the handle anti-clockwise to twist off - yet I feel it should be the other way round. It is the type without the button. It seems to have problems staying up - and tricky to push right down also...
Steve
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A couple of things can really help the handbrake operation:
- on a fresh brake job, always adjust the rear brakes with the handbrake disconnected at the wheels. That ensures maximum handbrake travel and leverage at the wheels.
- the longer the travel at the handbrake lever, the less mechanical advantage is available. Poke your head under the dash and look at the handbrake lever and linkage. As the lever gets to the end of its travel, it is no longer pulling the arm straight back. Very important to have the cable adjusted so it does most of its work in the first part of the travel.
With careful set-up, my handbrake works pretty good.
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Rather than adjust the hand brake cable in the black hole in the tunnel, I take up slack where the cable clips on to the rear trailing arms, by cutting a small bit off large spring washers so they fit over the cable, and then packing out the metal end of the hand brake cable outer. I have used 3 spring washers on each side without the outer falling out of the housing on the trailing arm.
Much easier than 2 x 1/2" spanners down the hole, and less damage to hands etc. Dripping blood does tend to stain the cloth insets in the seats.
Alex in Norfolk.
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Good idea. Now that my handbrake horse shoe is completely obscured by oil cooler and ac lines, I was thinking of doing the same thing.
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That all sounds very interesting. Alex - I read your theory on previous post - and sounds completely logical!
I will have a look under the dashboard - is there adjustment on the cable connected directly to the handle?? - or could it be that it has stretched??
I adjusted the rear brakes with handbrake not connected - and then connected handbrake cable such that the brakes don't bind. When I look in the tunnel when pulling the lever there seems to be a lot of slack to take up before it finally transfers action to the brake shoes.
Steve
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The cable from the umbrella to the reaction lever is short and not adjustable. The cable from the reaction lever to the horseshoe in the black hole is about 24" long and adjustable by 2 x 1/2" nuts which lock together and are an absolute pig to get two. Two hands in the hole just don't fit, so you need to improvise.
If they had threaded each end of the cable outer where it ends by the drum, adjustment would have been a doddle. So I improvised the adjustment with cut spring washers. You just use big side cutters (electrician stuff) to cut about 3mm out of the spring O to make it a C, and stack them on the end of the outer, equally each side, until the slack is taken up. Simples.
Alex in Norfolk.
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I also have a problem with the handbrake ratchet which I haven't sussed out yet. I seem to have to twist the handle anti-clockwise to twist off - yet I feel it should be the other way round. It is the type without the button. It seems to have problems staying up - and tricky to push right down also...
That sounds right Steve, mine is pull towards you and twist to release.
Controversial now, but I think the handbrake as designed is poor. You can get the 25% pass mark for the UK MoT but it takes care. In support of that statement if you look back through period road tests you'll see they also found poor handbrakes when new. Autocar quoted the S2 as "ok for parking on level ground, wouldn't hold on a 1:6 slope and very little use as an emergency brake". By the time the TCS had arrived Motor said "the handbrake is still rather pathetic, very poor".
So if Lotus sent out road test cars with poor handbrakes, you're allowed to struggle !
However there are ways forward. I think it was Richard on the Yahoo group who re-drilled the backplate to rotate it a few degrees. This means the actuating lever isn't bent to clear the trailing arm and he reckoned the revised operating arc made a big difference. That sounds a good idea if you look at the operating arc but by the time I'd picked up the comment I'd moved on. (I might be wrong on attributing it Richard, but the method I remember)
Mine has never actually failed on the handbrake but it has caused "comment" and knowing looks. Things improved slightly with a new rear cable with modified rear shoes to alter the point at which the backplate lever started to engage but then I gave in and fitted dual circuit brakes because a side benefit is that the pass mark is lower (18% ?). But actually getting it to stop the car before you get bored, you need rear discs..... ;)
Brian
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I did waste a bit of time trying to undo the nuts in the tunnel with a spanner on the end of mole grips - before I realised they were finger tight anyway! I will have a think about making some 'C' spacers - but I feel if anything they are needed at the front. Someone has added an additional tensioner in the tunnel which can be turned by hand - I will photograph when I get a moment.
Talking hypothetically - if the handbrake system used rods instead of cables - if you moved the handbrake 1mm - you would get a reaction at the other end. The way mine seems to be set up is that it is adjusted so it is correct at the brake shoe end - so you would expect the handle end to be automatically correct - but there seems to be too much slack there.
I cant quite picture why rotating the back plate would make a difference - but I am not disputing it.
Will have another look today...
Steve
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With the reaction lever giving a mechanical advantage of in the region of 6:1 or even 10:1, any adjustment between the umbrella handle and the reaction lever would have very little effect on the stretching on the cable between the lever and the horseshoe.
I think that the stretching is mostly on the very long U cable from the drum to the horseshoe to the drum, and this can only be taken up on the cable from the lever to the horseshoe, or the very long U cable.
Lotus in their wisdom thought we could get our hands into the tunnel to adjust the cable. Any adjustment there would be half the adjustment to the long U cable, but as I have found, any adjustment at the drum end of the cable is simplicity itself. We should ask Richard at Banks to get a 3/8" UNF thread cut in each cable end to take a pair of about 9/16" nuts.
Alex in Norfolk, far closer to Hethel than Banks in Preston.
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You want less movement at the brakes; that's what gives you mechanical advantage.
I suggest you take the clevis pins out of the rear brake levers, one at a time, and ask someone to operate the handbrake. You will soon see if you have free movement throughout.
Sounds to me as though your bowden cables are partly seized.
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This is a picture of the adjuster in the tunnel - which can be adjusted with one hand. The handbrake seems as good as it can be at the moment - but I haven't tried driving the car or moving it to a slope. I made the stupid mistake of thinking that I had to pull the hand brake - then twist to hold it in place when on - so maybe I don't have a problem with the ratchet...
Surely mechanical advantage is no use if when the handle is pulled to the maximum - the brake doesn't work??
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Hi Steve,
That's not the normal adjuster, or at least not like the OEM one on my car although I'm sure it will work. That's the sort of thing I've seen for when your cable is too long for the application and you need to shorten the overall length to get the lever arm movements back within range. I've not explained that very well I know, but perhaps someone else will be along with a better one.
The tunnel adjuster on mine is like the image. I think you'd get more effective adjustment than the one you've shown.
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:I-agree:
That looks like a DPO part, (Looks new) also looks like a good way to wear a hole in the coolant pipe...
Mine has the "horseshoe" as in Brian's pic.
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I agree with Brian and blaster. That is not the adjuster for a TC. I think the stock horseshoe provides a greater range of adjustment.
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On one of the cars I bought, the cable from the lever to the horseshoe adjuster was tied in a simple knot to shorten it !
I believe the handbrake does not work properly purely because the total cable and leverage system just does not move the lever opening the shoes apart enough to provide sufficient friction on the drum to stop the back end.
Quite honestly, I cannot understand how 1 side only of a moving brake shoe can ever stop a brake drum efficiently. Surely it needs two hydraulic pushers to make the shoe push on the drum sufficiently to work properly.
I will look at the back lever with increased concentration to see if improvements can be made on the hand brake mechanism, simply. Same movement at umbrella required for more movement at the shoes.........
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The wheel cylinder "floats" in the backing plate so it works on both shoes.
John
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The wheel cylinder "floats" in the backing plate so it works on both shoes.
John
That was my understanding as well, with everything clean and new spring clips it is possible to push the cylinder fractionally either way. We're not talking about a lot of movement here, maybe 0.025 to 0.040 " ? I've never tried to measure but it can't be a great deal.
Before I gave up with the rear drums I did spend some time trying to get a decent handbrake. On mine I found I was "losing movement" at most points due to wear so replaced the cylinders, the actuating arms from the cylinder to cable (Triumph parts) and fitted new pins. I even tried the "handbrake helper", a sort of modification that Triumph issued at one point to increase leverage so the efficiency of the handbrake seems to have been an issue with the Triumph boys as well.
An illustration towards the end of this thread http://www.lotuseuropa.org/LotusForum/index.php?topic=108.msg9594#msg9594 (http://www.lotuseuropa.org/LotusForum/index.php?topic=108.msg9594#msg9594)
The most improvement I had was modifying the shoes themselves which altered the angle of the backplate actuating arm and put it's rest position hard up against the backplate. Then I found the "steady plate" part, not in the parts list but apparently standard and does the same job. Some guys on here had them fitted from new but I'd never seen them on my car. Again, pictures on the previous thread.
The photo here shows where I ended up. This did work with little travel at the umbrella handle but I'd not claim it to be a good handbrake. I never tried the test used by Autocar which was to measure the stopping distance from 30mph (over 200 feet) but I'd be surprised if it was any better.
Brian
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The strange adjuster in my tunnel is just an add on. I have the usual set up with the 2 nuts and the horseshoe - but I suspect it was added to take up the slack in a stretched cable - which despite looking like it was designed by Fred Flintstone does the job quite well - and can be modified by one hand.
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In recent years I have used a vacuum oil extractor to bleed and flush brake fluid through the lines.
Very easy to use and almost no chance of making a mess as the fluid all gets sucked into the vacuum bottle.
I bought one to suck the oil out of my Smart (no oil drain plug in the sump) but as it came with a set of tubes for brake bleeding I gave it a go and became a convert to this method.
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In some systems, the vacuum method may suck air past seals.
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I'm sure it could, on three different cars to date I haven't had any issues.
Have replaced the Europa brake fluid (including replacing lines along the radius arms) and it made the job easy.
I do have a quite large receptacle so don't draw much of a vacuum, a couple of pumps seems to be enough and allows a lot of air and/or fluid to be drawn from a corner.
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I tried the vacuum pump system on my TCS to bleed the brakes, but it draws in air, I suspect via the threads on the bleed nipples.
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You need to put some grease on the threads first. I might have even used copper grease on a clutch slave cylinder I did (not Lotus...)
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good idea, I'll try that.
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On the topic of sealing the threads on bleed nipples, these days I usually wrap a couple of turns of that ptfe thread seal tape that you use for plumbing. In fact I seem to use it in a lot of "non-plumbing" applications, the drain plugs on engines and gearboxes for starters !
Brian