Lotus Europa Community
Lotus Europa Forums => Garage => Topic started by: analogmike on Thursday,December 31, 2015, 12:59:23 PM
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Hi,
I finally started driving my '74 Special and I'm really starting to like it, though it still needs sorting.
The brakes are very weak. I found the front calipers were stuck so I exercised them and flushed the brake fluid with Castrol and they are working now. Rears are working fine with new slave cylinders. But the pedal effort is still very high though I can lock up the brakes if I try hard.
I pulled the vaccuum line from the boosters and plugged it, with little change in pedal effort. So I guess the boosters need rebuilding. I'd rather do that and keep the car original than install a smaller master cylinder. Does that sound like an accurate assessment, is there something else that could be wrong (I am getting vacuum but have not measured it yet, parts stores don't carry vacuum gauges like they did in the old days!).
Should I attempt to rebuild them myself, and if so where do I get parts?
Or is there someone who will rebuild them for a decent price?
Or if I modify the brake lines around the boosters, will the brakes work better with them bypassed than dead? I am really good with older Porsches and they had no vacuum assist so I am not familiar with how they work.
Any help appreciated, happy new year!!!
(not enough room for my guitar gear, so I made two trips!!)
(http://www.analogman.com/graphics/lotusguitarcases.jpg)
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Europas are definitely not meant to haul bulky rigid containers!
I can't tell you about the difference the boosters make since I've only driven my car with boosters - the Girling when new and I used Lockheed when I rebuilt it. I suspect it makes a difference since I don't think Chunky would have added either the weight or the cost if he didn't think he had to, but YMMV. This might be helpful if you decide to go boosterless: http://gglotus.org/ggtech/europa-brakes/tcbrake1.htm. There may be more ideas here: http://lotus-europa.com/manuals/
If you do decide to keep them, rebuild kits are sometimes available on ebay. I just saw some that look like they are for the Europa boosters, but I don't know the actual designation for the Europa booster so those may not fit. While I've taken a booster apart, I've never rebuilt one so I can't speak authoritatively on it, but it didn't look that tricky.
If you would rather have them rebuilt, I would advise you to contact White Post Restorations (whitepost.com). They did a nice job on my rear calipers and M/C and they seem to be able to restore anything. They also have a fast turn-around.
Good luck and Happy New Year!!
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With the cost of rebuilding the boosters running about $450 per unit (Apple Hydraulics), you may want to try to see if you can live with bypassing the boosters first. The alternative is finding some Lockheed replacements. I suspect they'll cost the same as the rebuilding the Girlings. This thread has some pictures of how to run the bypass lines.
http://www.lotuseuropa.org/LotusForum/index.php?topic=1069.0
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Hi Mike
The standard way a mechanic tests brake boosters (servo in UK) on our annual MoT test here is as follows;
Ignition off, car stationary & press the brake several times. This is to remove any residual vac. in the line & servo itself.
After 3-4 presses then press hard & hold the brake pedal down and whenever I've done the test I've used my left foot so I can blip the throttle with my right.
Start the engine. As the engine fires, revs rise and a vac. establishes which and then the servo kicks in and you can feel a slight downward movement on the brake pedal. It's not a lot and I couldn't even start to estimate how much but it is noticeable.
No movement at all and your car fails the MoT because if a servo is fitted it must be working. Take it off completely and it doesn't matter how hard the brakes are to press, there's no problem with the test..... it's a Brit thing ;)
Sticking servos were a regular feature of over winter storage on my cars. Once the above test failed I'd do the usual checks for hose connections and then move to the servo. 99 times out of 100 it was one of the small internal valves sticking and the servo cylinder seals themselves were ok and not leaking. Careful dismantling & cleaning usually got it working again without any problem and it would be fine until the next lay-up !
Brian
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Thanks for the replies!!!
I have been thinking I should pull one of the boosters apart and see what it looks like before I go much further. I think it has been sitting a while, maybe I can get it unstuck without a total rebuild. Or if I need parts, it looks like I can get rebuild kits / parts from Power Track Brakes in the UK. There is a great article about successfully rebuilding them here:
http://www.lotuselan.net/forums/lotus-suspension-f42/lockheed-brake-servo-rebuild-kits-t27431.html (http://www.lotuselan.net/forums/lotus-suspension-f42/lockheed-brake-servo-rebuild-kits-t27431.html)
And that article leads to some nice pictures here:
http://www.triumph-spitfire.nl/servoimages.htm (http://www.triumph-spitfire.nl/servoimages.htm)
Maybe I can do some of this without even removing the boosters from the car.
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Those are the Lockheed boosters. This video should be useful for rebuilding yours (https://www.youtube.com/watch?v=quRJ4_sqMYU).
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I thought we had Lockheed, mine look more like the Lockheed than the Girling. I can;t find decent pix of the boosters with Google, just this one which is nothing like mine
(http://www.lotus-europa.com/manuals/misc/body/Body_Removal_files/image026.jpg)
Here's a slight shot of mine:
(http://vintageracecarsales.com/wp-content/gallery/lotus-europa-2/P1080796.JPG)
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Ok! The top picture has the stock Girling boosters. You have the Lockheed boosters like mine. Mine are probably 25 years old, but they have few miles on them, and they seem to be working fine so far. I'll have to print off those instructions for when I have to rebuild mine.
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Get in touch with R.D. Enterprises. They have new sets available for about $500. You may have to fiddle with the mounting, but they will definitely work. Personally, I am removing mine altogether. I plan on trying some different pad compounds if I do not like the feel. I mean, a bunch of folks run without the boosters, and the car is only 1500 lbs or so, so I think it would be Ok to forgoe the boosters. But we'll have to hear some opinions from folks more educated on this subject than I.
I also work on my 1984 911. The Porsche is so easy to work on. The Lotus is painful in comparison.
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I also work on my 1984 911. The Porsche is so easy to work on. The Lotus is painful in comparison.
:) they have clearly changed since 1984 then......
it took me two days (yes, two days ::) ) to change the serpentine drive belt on our Gen 2 Cayman last summer. Ok, part of that was me going slowly because I didn't want to mark any of the trim, but even so getting the belt in place was a seriously hard job.
I guess it's just what you're brought up on. I can think of a few awkward jobs on the Europa but mostly they are very simple and straightforward once you get to know the car.
Brian
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Thanks for the replies.
I did more digging, and found the boosters are fairly recent, though the PO had trouble with them too. The mechanic wrote him a note on the receipt:
"Poppet valves on the new boosters were stuck because you don't drive the car enough, drive it every week, it's fun!"
I got a vacuum gauge and tested the plumbing etc and after cleaning everything up, am getting about 10psi at idle. It's all PULSES though, I had to make a vacuum reservoir out of a small gas can to read the actual pressure. My boosters are not leaking vacuum, and those white round things on top are holding vacuum for a while after I turn off the car, I pulled them apart and they were pretty clean. I think those white things are servo (booster) air valves, and the poppet valves are inside, so I may need to disassemble the boosters to unstick them. I would think a vacuum reservoir with a one-way valve would help this brake system work better, to keep vacuum in the boosters. But maybe that's what these white air valves do?
The brakes are working a little better now, but I still don't think I am getting much boost. I will check out that video when I have time and see if he shows the poppet valves.
I did improve my shift linkage a lot, will post in another thread about that.
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If your servo is the same as I had fitted, mine came from an MGB.
This page http://www.mgb-stuff.org.uk/servo.htm (http://www.mgb-stuff.org.uk/servo.htm) has a description of how it is supposed to work, plus some of the best cross sectional drawings I've seen in a while. I used it when mine used to stick (before I junked them :) )
Brian
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"1984" is the key phrase here, LOL.
I'll send you my 1984 for the Cayman? I love those cars. All my rich friends are now buying GT4 models.
I also work on my 1984 911. The Porsche is so easy to work on. The Lotus is painful in comparison.
:) they have clearly changed since 1984 then......
it took me two days (yes, two days ::) ) to change the serpentine drive belt on our Gen 2 Cayman last summer. Ok, part of that was me going slowly because I didn't want to mark any of the trim, but even so getting the belt in place was a seriously hard job.
I guess it's just what you're brought up on. I can think of a few awkward jobs on the Europa but mostly they are very simple and straightforward once you get to know the car.
Brian
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OK I finally got my power brakes working!!
It was the poppet valve stuck, the thing that pushes up on the little white round thing on top of the booster, to release vacuum from one side of the booster to provide assist. There was always vacuum in my boosters as the poppet valves never released it so there was never any brake assist.
This is an easy job though I could not find a single explanation on the internet on how to fix a stuck poppet valve.
How to unstick a Lockheed Brake Booster
For diagrams and "how it works" see this link
http://www.mgb-stuff.org.uk/servo.htm
1) pop off the little top vent air valve cover, just snaps on and off, be careful not to lose the spring!
2) unscrew the 5 philips head screws that hold the round top of the white plastic air valve diaphragm assembly.
3) carefully remove the cover, don't rip the diaphragm. Then you can pull it off the vacuum hose easily by rotating it up.
4) carefully remove the diaphragm.
5) There will be 3 larger philips screws holding the air valve diaphragm assembly bottom metal plate onto the brake booster. Remove these.
6) The bottom plate will pull off and you can see the air valve piston top in the middle. This is what's stuck. Clean it up and soak it with some PB Blaster. One of mine was VERY stuck, so I found a tapered EZ OUT with sharp splines and tapped it in gently, till it moved a bit, then turned the piston till it was free. Be careful you don't want to push it down too far. You may find a nicer way of freeing it. My second one was not stuck so bad, I was able to get it moving much more easily and lubed them both up.
(http://www.analogman.com/911/europabooster.jpg)
7) Clean everything up well, lube the rubber parts a bit and put it together and you should be all set!
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:trophy:
Thanks for posting the 411.
So how do you like stopping with the boosters as compared to without?
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Thanks for the DIY and the link! That could come in very handy!
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:trophy:
Thanks for posting the 411.
So how do you like stopping with the boosters as compared to without?
Good question!
I have only driven it once so far, I am heading home from work in it soon, midnight Sunday is long enough!
I have CRAPPY KUM-HO tires on it, they can't take much braking before they lock up. The fronts are locking up first, which is correct and I think I can hear the rears kicking in too if I keep pressing after the fronts lock.
In normal driving, they start out without a lot of force, then when you press a little more the boosters kick in and you get a NICE amount of boost - not as bad as my Audi S3 which is overboosted. I squealed the tires a few times just feeling them out without trying to brake hard. I think with some practice I will really like them, glad I got them working instead of bypassing them as most do.
update: driving home I tried some hard braking at higher speeds like 40mph, and the fronts are locking up too soon, they are too sensitive. I will have to check the rear booster. I previously adjusted the rear drums as tight as they could go before dragging and bled them well so they should be good. These boosters are not the stock ones, the ratios may not be quite right.
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I did some brake testing in my parking lot, and sure enough the rear brakes are not working much. I even plugged the front booster's vacuum line, and the fronts are still locking up a bit before the rears. The rear booster is getting good vacuum but not boosting. Will need to do more testing, it may have a bad main diaphragm. I know the rear brakes work, as they were the ONLY working brakes when I got the car (front caliper pistons were seized).
And the speedo stopped working this week too. I hope I can fix things faster than they break.
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The fronts should lock up a bit before the rears. If the rears lock first, the car will try to swap ends. There may also be an issue with the brake adjustment in the rear. That's not to say your rear booster is working properly. Rebuild kits are available for the boosters, but if it is the booster, check it to make sure it's in good enough shape to rebuild. The aluminum body can get pitted from corrosion. White Post Restorations (http://whitepost.com/) says they can rebuild anything. If it needs it and you're not up to rebuilding it, they would be a good option.
As for the speedo problem, check that the cable isn't broken. That's a pretty common occurrence. It could also be that the speedo gears in the tranny are stripped, but I think that's much less likely since the shards from that would probably interfere with the operation of the tranny (I was left with 3rd and 4th gear when that happened to me).
Take heart! I'm sure you'll catch up with your car! These cars are simple enough that there aren't that many things to break!
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I hope I can fix things faster than they break.
:) now that's a tough call, this is a Lotus y'know ? Lots Of Trouble, Usually Serious....
But back on topic, like BDA said the speedo cable is quite long and is known to fail because if it's not lubricated well or the outer has sharp bends, then it must have quite a bit of stress on it. I think the Europa is the only car I've ever had to replace cables, and looking back I've done it twice !
On the brakes, the front/rear brake balance is a topic that's been discussed quite a bit, and without meaning to upset you it could be that your car is fine but the driver needs adjustment.... (big smile here).
Europas are light at the front and braking sharply it's all too easy to lock the fronts. It's been discussed a lot on the Yahoo group and in the group files section there are brake calculators which show the rear brakes only contribute something like 25% in the overall scheme. Hence the reason there are rear disc conversions around to increase this to 30-35%.
But some guys (Jay Mitchell ? apologies if it's the wrong guy) pointed out that driver technique can make the stock brakes work fine. The trick I find is to apply the brakes lightly for the first touch until you can feel the weight transfer coming in to load the front wheels, then go heavier. Easy to do driving normally, not so much in a panic stop.
If it's any consolation I have wider, modern tyres all round, no servo and rear discs but I can still lock up the fronts if I stab on the pedal.
Brian
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If it's any consolation I have wider, modern tyres all round,
Do you have any problems with the wider tyres hitting the back of the wheel arches on the front when turning?
Alex in Norfolk.
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Do you have any problems with the wider tyres hitting the back of the wheel arches on the front when turning?
Alex in Norfolk.
Hi Alex,
Nope, or rather not that I've seen and I do use full lock to get in and out of the garage. Likewise I've not seen any marks in the arches after driving but then again the suspension doesn't move a lot these days !
I know that on the S2 with the same size wheels/tyres there is a slight rub on full lock because Richard told me about his, but I think the TC has a different footwell arrangement ? I suppose it depends on the wheel offset/inset and could be calculated but I'm afraid I just bolted them on and then looked for rubbing marks.... :-[
Brian
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With 6" x 13" Minilites I had to use thin spacers to stop the inside of the wheel hitting the suspension wishbones, aluminium hitting steel and making horrible grinding noises. Now I have black rubber on fibreglass instead.
I will see if thinner spacers stop both things happening.
Alex in Norfolk
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Thanks for the replies!
You don't know me, but I'm a 2 time SCCA National champion (1st was 30 years ago!) and built and set up my winning 911S myself (even lighter in the front), and also won an IMSA race in 2011 in GTC class in a 911 GT3 cup with TRG, so I have a very good feel for car setup. The rear brakes are definitely not getting any boost. I just need to do more testing to figure out what's wrong. Both of my boosters are fairly new, so should be able to get the rear working again.
When I get them working I will get some decent tires, I think the Toyo 185/60 and 205/60 should fit the stock 5.5 rims and are about the only good choice available. A British race engineer I work with told me about Avon CR6ZZ competition tires which come in the stock sizes but a lot more $, I wonder if anyone has tried these? They would look more original and be more fun to slide :)
http://www.avonmotorsport.com/historic/historic/cr6zz
Thanks again, getting it sorted little by little while enjoying it!!!
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I'm running 195/50-15s on the front and 205/50-15s on the rear and I don't get any scraping. Unfortunately, I don't remember what wheel width I have or what their offset is (I suspect they're 6 1/2" or 7" wide and I tried to preserve the same proportional offset as the original alloys). I did get a little scraping early on but that could have been before I changed the offset of the front wheels. I think Brian is right that offset matters. However, I did get some scraping in the front under some circumstances with the stock alloys and tires with one of the Europas I've owned. That was a long time ago and that's all I remember about it. It could have been that I had a rear wheel on the front - but that doesn't answer why I'm not getting any scraping now. I think there might have been a QC issue but I have no idea how tolerances would stack to allow that.
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Hi analogmike!
That's quite a record! :trophy:
Let us know what you find out.
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Swap brake feed and supply lines on the boosters. If only one booster is bad, it should show up. Finally, bypass the boosters and see what that does.
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A British race engineer I work with told me about Avon CR6ZZ competition tires which come in the stock sizes but a lot more $, I wonder if anyone has tried these?
I have the Avon CRZZZ 295/15s on my other toy. I haven't lost traction in the dry, but I have swapped ends easily in the damp.
Alex in Norfolk
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You don't know me, but I'm a 2 time SCCA National champion (1st was 30 years ago!) and built and set up my winning 911S myself (even lighter in the front), and also won an IMSA race in 2011 in GTC class in a 911 GT3 cup with TRG, so I have a very good feel for car setup.
:-[ and here's me trying to tell you how to brake...... apologies for trying to "teach granny to suck eggs" Mike.
For no logical reason at all other than the reference to Audi I'd just assumed you'd moved from a modern car to one of these old things and were having the usual driver-adjusting problems, which is clearly not the case.
From the posts so far it sounds as if the servo's are now sorted, the rear drums rebuilt with new cylinders and so the only other areas I can think of for poor rear performance are the rear lines (trapped, bent/kinked), the short flexible to the rear suspension arm and the feed from the master cylinder itself. Bleeding the system would have highlighted poor fluid supply from kinked lines, so unless either the flexibles or tandem m/cylinder compartment are failing under pressure, I'm struggling.
There might be an "expectations" issue involved especially if you're comparing with Porsche, who probably put a touch more engineering into their cars.... ;)
Brian
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Thanks for the feedback on the Avons, Alex. I don't usually drive my toys if there will be rain, so I'm not concerned about wet performance. Just have to decide if I want the Avons in stock size or Toyos in 60 series and wider...
Brian, I think there is certainly validity in what you said about the rears being weak, but they were certainly TOO weak and now I think I know why.
Today I popped the plastic tops off the boosters, got the car running then turned it off, with vacuum being held in both boosters. I pushed on the brake pedal with a long stick and sure enough the poppet valves popped up nicely, the rear first. So that was not the problem.... my poppet repairs worked fine.
I pulled off the brake drums and remembered that I had driven with the parking brake on quite a distance last fall, and the drums got very hot. The shoes did not look too bad, but I think they were glazed. So I sanded down the shoes and drum with some rough sandpaper and cleaned them with brakeleen. Then I drove around gently and started using the brakes. They felt better... after several brakings I stopped and felt the brakes, the rears are getting nice and hot now, both sides working! So I think the booster is working fine now and I have better friction to stop the car. I didn't drive much after that short drive, but washed the car (first time it's been wet since I bought it) and will try to bring it to Caffeine and Carburetors in New Canaan, CT tomorrow morning, that should be enough driving to see if they are ok.
I noticed the pads are pretty new, DELPHI brand. I remember my last car with drum brakes was a 240Z about 30 years ago, and the rears were weak too, I put on some "green stuff" shoes and that helped a lot. If I think the rears still need more after breaking them in right, I may look for a more aggressive pad.
Thanks again!!!
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I am putting 459 bhp through the 295/15 Avons and they cope well in the dry on a racetrack.
Alex in Norfolk.