Lotus Europa Community
Lotus Europa Forums => Garage => Topic started by: Gmg31 on Sunday,December 31, 2017, 02:24:21 AM
-
I started a thread on this a while back but can’t find it to update, sorry for starting again.
During my restoration project I’ve replaced every single component in the braking system but despite my best efforts I cannot get the system bled. There are no leaks, I have double checked. I’ve bled the master cylinder, I’ve tried the traditional manual way and I bought a vacuum bleeder. I’ve done it a dozen times over several weeks and absolutely no brake pedal, not even half a spongy pedal, absolutely nothing. I am coming to the conclusion that the new master cylinder must be duff. I cannot bare the idea of replacing it now that the body shell is back on, it actually looks impossible.
My last effort is, I have bought a male to male connector and I’m going to join the master cylinder brake pipe directly to one front wheel and see if I can get that to work by eliminating everything else.
Any other pearls of wisdom would be very welcome please. Especially how to replace a master cylinder when there is absolutely no access the bolt heads inside the chassis.
-
The M/C on TCS are held in place with 5/16" studs and 1/2" diameter self locking nuts. What is different on yours?
I have the same problem bleeding the brakes on 4688R.
I am thinking of taking the car on a trailer to a local garage where they have a machine which pressurises the header tank with fliud, so all the air is pushed out direct from the reservoir.
-
Have you done a bench bleed of the master cylinder before installing it? How did the pushrod feel on the vise when pushing it in?
-
Removing the m/cyl looks bad but in truth it's fairly straightforward (or perhaps I've just had way too much practice with trying out different ones :) )
I normally remove the closing plate which gives great access from both sides although I suppose you can get by without doing so. Release the connecting rod and then it's just a the m/cyl bolts and it's free.
But before doing that, if you really do have no pedal at all from the m/cyl, then firstly I'd crack the outlet and see if any air comes out there, sort of "bench bleed on the car" if you like. Personally I can't see a new m/cyl being having duff seals but if I did suspect it then I'd just block off the outlet (bleed nipple same thread ?) and see if I could get a pedal on the cylinder alone.
I can't say I've had serious problems getting the brakes to work but I've certainly got better results with pressure bleeding. I've got a modified cap which I can pressurise but the old fashioned Gunsons Ezibleed using a spare tyre would be equally good enough to blow fluid in a continual stream through the individual lines. That is better than using the brake pedal alone, you get a good volume coming out in each "push" and less chance of bubbles drifting back to high points.
Brian
-
I didn’t bench bleed it before fitting it, I didn’t know that was recommended but having been given that advice the last ime I posted this I have since tried to do it in situ. My presssure bleeder goes on the bleed nipples and sucks fluid through. So I disconnected the outlet pipe from the T piece and bled it that way.
I like the idea of screwing a bleed nipple straight into the outlet on the MC that will either work or not and it will be very clear what the fault is if that doesn’t work.
My MC is bolted on from inside the chassis with absolutely no acces point once the shell was refitted. Had I known I was going to have this problem I would have tried to weld the bolds in place.
I’m considering opening up an access port on the bottom of the chassis just big enough for a spanner and then welding a disc over it when I’m done.
-
Sometimes you can access the m/c nuts/bolts through the hole in the chassis for the m/ pushrods. It isn’t easy but it is possible.
-
I didn’t bench bleed it before fitting it, I didn’t know that was recommended but having been given that advice the last ime I posted this I have since tried to do it in situ. My pressure bleeder goes on the bleed nipples and sucks fluid through. So I disconnected the outlet pipe from the T piece and bled it that way.
Bench bleeding isn't in the manual and although you'll find lots of Youtube videos on the subject, I wouldn't say it's common practice. With a single system I've never bothered myself and the first time I tried bench bleeding was with the tandem m/cyl, mainly because I was unsure as to how well it would fill with fluid. With the positioning of the m/cyl on the Europa I'm not convinced it's any advantage as fluid drips out as soon as you try to connect the lines, the alternative of trying to fit the m/cyl with lines connected seemed impractical as I wanted a single run for the rear system.
My MC is bolted on from inside the chassis with absolutely no acces point once the shell was refitted. Had I known I was going to have this problem I would have tried to weld the bolds in place.
I’m considering opening up an access port on the bottom of the chassis just big enough for a spanner and then welding a disc over it when I’m done.
That's tough. If you do go the access port route then rather than try to tack the bolt heads in place I'd be tempted to make the hole slightly larger and fit a backing place with studs, like the image from the manual. If there's no way you can get a spanner to the bolt heads through the central hole then I'd do the modification. It will be easier now while the car/chassis is clean and at some point either you or the next owner will want to service the m/cyl, if only to replace the seals.
-
Before trying to remove the M/C, I would block off the outlet port on the master cylinder as Brian recommended and see if you have a solid pedal first. At least you would know for sure that the M/C is bad.
-
Are you sure the rod is adjusted so the master cylinder plunger returns all the way, opening the inlet port? If not it will never take fluid in.
-
My MC is bolted on from inside the chassis with absolutely no acces point once the shell was refitted. Had I known I was going to have this problem I would have tried to weld the bolds in place.
I’m considering opening up an access port on the bottom of the chassis just big enough for a spanner and then welding a disc over it when I’m done.
The federal S2s have an access port in the middle of the front "T" section of the chassis where I was able to reach in and remove and replace the M/C backing plate. Do the non federal S2s have the same setup?
-
Yes mine does have that but surely it’s impossible to reach the bolt heads from there....
-
Are you sure the rod is adjusted so the master cylinder plunger returns all the way, opening the inlet port? If not it will never take fluid in.
If I’m reading that right are you suggesting the rod could be adjusted too long or too short to pick up fresh fluid. I adjusted mine to be long to get maximum travel along the cylinder but you seem to be suggesting that is wrong?
-
I can see what Clifton is on about with the stroke on the cylinder and there's an optimum range. When I changed to a tandem m/cyl, I took this photo of the old pushrod to establish the length for the new one. That's assuming you have the UK set-up with single circuit, if you have the Federal set-up with a pivot arrangement then I can't help with those measurements.
It's difficult to set the length while installed, but surely all you have to do is remove the pin from the brake pedal end and that insures that the piston is returning to it's stop and you have maximum travel ? If the pushrod is too long then I'm not sure how you'd manage to bleed the brakes at all, but I could see the incorrect length affecting brake performance, maybe causing them to bind or apply the servo.
FWIW I only used those dimensions as a guide to making a new pushrod. As you can see I favour an adjustable end by the brake pedal which you can reach easily from the footwell so I just tighten it up until there's only a tiny fraction of movement at the pedal before the piston starts to move. And of course it makes it easier to adjust the pedal position.
Brian
-
Mmmmm that’s alll very interesting. Thanks. I’ll start with that this weekend and see what happens.
Thanks everyone.
-
I second EuropaTC on pressure bleeding. I can pressure bleed all 4 wheels on my federal TC in 30 minutes.
You didn't say if you are using boosters. On the federal cars the stock setup was dual boosters, removing them along with the all the associated brake lines makes a huge difference in bleeding difficulty.
-
Yes mine does have that but surely it's impossible to reach the bolt heads from there....
No it isn't, with a longish ring spanner (box-end wrench).
Before you put them back, drill holes in mild steel strip and brazen the bolts in them the strip needs to be long enough to stop the bolt rotating when you tighten the nuts. You'll never have the difficulty again.
-
Apologies to anyone who has seen this moaning tirade on other pages, I’m running out of ideas and patience.
1970 S2 Europa. Full restoration every component of the braking system is brand new, no servos. I have spent weeks trying to bleed the brakes and I cannot get a pedal at all.
Normal manual bleeding 10 or more times. Nothing
Pressure bleeder, nothing.
Following advice Here.
I disconnected the pipe from the MC that goes to the T piece and added a bleed valve to the end. I then bled the MC. With the bleed valve shut the pedal was rock hard so clearly the seals inside the MC are holding.
I then connected that same pipe directly to 1 front wheel and bled that, all ok working fine.
Reconnected the pipes as they should be and bled the whole system half a dozen times, manually, with an eazi bleeder and with the pressure bleeder. Nothing.
Adjusted the connecting rod from the pedal to the MC tried it shorter and longer nothing. There are 4 flex unions on the rear non are leaking, 4 flex’s unions on the front non are leaking 2 Brass T pieces neither are leaking. Rear cylinders new, checked not leaking. BTW When I say ‘nothing’ I mean absolutely nothing, the pedal just goes straight down to the floor, not even a soft spongy pedal.
Question with no visible leaks how can air be getting into the system, surely even the slightest air leak would cause fluid leak.
-
gee, this is getting a bit serious. No need to apologise for having a good old grumble, we all do it, that's why we just love these old cars so much ::)
Firstly, if you can get a hard pedal with the m/cyl outlet blocked then it isn't going to be an actuating rod problem, so let's park that for the moment. It might need adjusting to get full travel or pedal position but shouldn't stop the brakes working. And the m/cyl has been ticked as well.
OK, get me up to speed with your layout....
I'm assuming you have a single circuit m/cyl with a line going from the m/cyl to a 4 way union just in front of the crossmember ?
From the 4-way you have 1 line outlet to each front caliper and then a single line going down the spine of the chassis to the rear ?
At the rear you have another 4 way union located on the chassis with one inlet from the front, outlets RH rear, LH rear and then brake pressure switch ?
If that's right and you're getting nowhere with the usual "bleed the furthest away first" method I would be tempted to isolate the front calipers by going to the front 4-way and replacing the outlet to the rear/central spine with your bleed nipple. Try for both front calipers working.
Is that ok ? If you can get a solid pedal on the front calipers we're chasing a rear problem and the transfer line is the first target. It's a long line and could easily trap an air pocket if you don't get a good flush there.
So replace that central line and if you can easily get to the rear 4-way, crack the front/rear transfer line so that as you push fluid through you can see it appear before re-connecting. Messy so you'll need a rag to stop the chassis paint getting attacked.
In fact if you have easy access to the 4-way I'd be tempted to remove the brake switch and use the bleed nipple to get all the air out up to that point. You can leave the nipple in place once it's clear and go for the rear brakes now, furthest away first.
Don't get too down about it. With the lines going up and down the car (even more with a servo system) there are plenty of opportunities to retain air bubbles in the lines. I aim to do a single line at a time and don't get hung up about flushing a complete reservoir full out at one go with my pressure system.
Yes, I waste a lot of fluid but it's cheap if you buy the big 4/5L cans from Halfords. £20-£25 ? well worth wasting a few quid to preserve your sanity !
-
Hi
Not to insult your intelligence, but when it comes to the rear cylinders, you've connected the pipes to the bottom, not the top? If you've connected to the top you'll never bleed the air out of the cylinder.
(Why are you messing with the pedal when you know when the rears are disconnected it works fine?)
Jack
-
If you have boosters SpeedBleeders are your best friend.
-
Europa TC yes you have described my system perfectly. i will work through your suggestions.
I don’t have Boosters, (Servos in the UK). A FB friends has suspected that the brake switch is a high point and can trap air.
Thanks for your suggestion everyone
-
Have you adjusted the rear brakes? The first time, you should adjust them with the handbrake cables disconnected.
-
A FB friends has suspected that the brake switch is a high point and can trap air.
Following on from your friend's suggestion, if your rear 4-way is arranged like the first image with the base horizontal then I'd put money on it being the culprit. Nowhere for the air to go.....
It sounds like your system is the same as mine used to be. I mounted the 4-way on the vertical section of the rear Y so it was like the second image, brake switch on the bottom.
Brian
-
Spent another whole day on this today. Turned the brass union at the back the other up so the switch is in the bottom. Bypassed the union at the front and connected the MC straight to the rear. Perfect rear brakes excellent. Connected the front on their own perfect. But Re connected them all together NOTHING.
have decided to do away with the front union and split the feed into two senate brake circuits using 3 T joints with their own bleed nipples. This is absolutely driving me mad.
-
have decided to do away with the front union and split the feed into two senate brake circuits using 3 T joints with their own bleed nipples. This is absolutely driving me mad.
Gee, this is crazy. Front works in isolation, Rear works in isolation but all together and it's not working ? I can understand your frustration, by now my swear box would be overflowing and there would be chunks missing from the workshop walls where missiles had collided.
But however bad it seems, you are approaching the problem in a logical manner. You've proved that the m/cyl, front calipers and rear drums do work independently, so it's got to be something about the line connecting front & rear. Somewhere there must be a hold up of air which isn't being taken out during the bleed process. If you can stand yet more questions.....
1. Did you take any photographs of the brake lines during the build so we can see how they run ? I have no idea how it will help but seeing the geometry might just trigger something.
2. When you connected the m/cyl directly to the rear brakes did you use the front to rear line on the car and if so, how did you get it working ? (layout)
If it's any consolation then you're not the only one stumped here. Without a servo and on a single circuit, this is a frustratingly simple set-up. It's crazy how air is being held up even with pressure bleeding. It's just a pity you're not closer to Lincolnshire, this is worth an afternoon of looking at.
Brian
Edit to add; following on from subsequent comments regarding m/cyl bore and travel, a further question. When you got either the front or rear working singly, how much travel was there on the pedal ? I would guess it should be around an inch or even less to fully apply either front or rear brakes. If it goes much further and won't reduce with pumping, then there is some mileage in checking the m/cyl bore you've got is correct. I'd be looking for 0.7", IIRC early cars had smaller ones but I'd expect you to be fine with 0.7" and no servo.
-
Is it possible that the master cylinder does not displace enough volume to activate both the front & rear brakes at the same time?
This could be caused by an undersized master, or not enough stroke on the correctly-sized master.
While bleeding the brakes, does the pedal go all the way down to the floor/carpet? ...If so, you may not be utilizing the full stroke of the m/c.
-
A few bubbles of air will give a slightly soft pedal, not no pedal at all.
A few questions:
- All new parts means what? Please describe exactly what was done. New? Overhauled? Parts sourced from whom?
- New master made by whom? Bore size?
- Did you confirm that the pushrod is not preloaded?
- Did you check that your rear brakes were properly adjusted?
-
New MC, new Callipers, new rear cylinders, all new pipes, new brake switch. Everything from Banks Europa Engineering. The only things not replaced are the two brass unions.
I’ve repositioned the rear union so the brake switch is at the bottom and this worked perfectly if ONLY the rear is connected up. Same at the front so the only part that is added when connecting everything is the Brass union at the front. So my plan is to ignore this and use 3 T pieces and create a duel system. Parts are on order so hopefully I’ll update this thread next weekend.
-
You should not have to change the lines from stock. Something else is wrong.
It’s my understanding that you have a single circuit m/c and that you have tried it with attached only to the front and then only to the rear. You say the brake pedal was then fine. Could you describe fine? Given the isolation of half the system, the pedal should have been very high and rock hard. Was it?
One other thing to look for is the wrong seals in the front calipers. I have only seen a couple of times but sometimes the calipers seal is too stiff and it retracts the pistons too far leading to a very low/non-existent pedal. Again it doesn’t happen often but it worth checking. Have your beautiful assistant apply the brakes while you watch the movement of the calipers pistons.
-
I don’t really want to admit to this but. Knowing this is a “safe space” where we all share and learn from each other’s mistakes. Id fitted the front Callipers on upside down. Clearly when I thought the front brakes had been working I was wrong. Duh
-
:)
We all live and learn, I've lost count of the daft things I've done over the years when "I don't need the manual for this little job"..... great news to hear you're on the home straight now.
Brian
-
I haven't done anything that stupid before. I've done (and from time to time I continue to do stuff) much more stupid!
But I'm confused. How does mounting the calipers upside down make them appear to work when they don't? It seems the bleeder would be at the bottom and you'd never be able to bleed them and so they wouldn't appear to work... I have a feeling I'm missing something simple and committing another stupidity.
So you're now able to bleed the brakes properly and they work as expected?
Edit: I see on the other thread that you got them working properly! That's great news!
-
I feel your pain. I almost did the same on my current build until I went to replace the bleeder screw and realized it was in the wrong place.
At least you figured it out.
-
Mistakes, the best teacher.
My mechanical skill I owe to the fact I have had the time to make a lot more mistakes than you have.
-
You don't get anywhere without making mistakes!! and learning from other's mistakes too!! (so well done for posting)
just read a book recently called "black box thinking" All about learning from mistakes!