Lotus Europa Community
Lotus Europa Forums => Garage => Topic started by: Sparkrite on Saturday,May 15, 2021, 11:00:20 AM
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I am trying to get my federal tcs roadworthy and I am now tackling the brakes. I have revised the rear drums with new wheel cylinders and then bled them . I wanted to pull apart the front calipers but had to settle for just bleeding them for the moment as I could not undo the brake pipe nuts.
However my question is why is does my brake pedal go to the floor. I am thinking it is something to do with the master cylinder,even though it was capable of bleeding the brakes.
The master cylinder is original with the large reservoir and palm sized cap.
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Yeah it sounds like your cylinder has given up the ghost
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I am assuming that you see no fluid leaks. I think a small leak that you are likely to miss would more likely give you a soft pedal but it's possible that a larger leak could be collecting somewhere you don't see. Check all your fittings. If you're unsure, wrap the suspect fittings or parts of the pipes with something that is absorbent and display the leak. I've used pieces toilet paper or paper towel in the past. You could try talcum power. I'm sure there are others.
You say your bled your lines. Did you get a pedal then? When did your pedal start going to the floor? As a reminder, you should start bleeding your brakes at the cylinder furthest from your M/C and progressively get closer to the M/C. Unless your brake system has been rerouted, the cylinder furthest from the M/C is the passenger side brake caliper.
When your pedal goes to the floor, are you using up brake fluid (i.e. is the fluid level in your reservoir going down)?
If your M/C is untouched it could require a rebuild in which case I would take it to a shop that specializes in restorations (including hydraulics, of course) and hopefully they would give you a bronze liner.
Do you still have your boosters? What shape are they in? Have they been rebuilt or replaced? If they are original, I would probably replace your M/C with a 0.70 size M/C and take the boosters out. If you've got newer boosters (eg. Lockheed), your fluid may be going into the booster in which case it (or they) will need to be rebuilt or replaced or done away with as described above.
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Did you have a hard pedal before doing any work on the brakes?
How did you bleed your brakes? If you did it the traditional way with the pedal, it's possible that the seals traveled into the part of the master cylinder bore that may have corrosion and damaged the seals during full travel of the pistons.
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Be careful about separating the front calipers as the seal between the two halves does not come in the overhaul kit. A few places carry them but they are not commonly available. Source the seals first before splitting the calipers.
The TCS system is very convoluted and complicated. Bleeding is difficult at the best of times.
- Brake pedal goes to the floor SLOWLY, reservoir is full and stays at the same level, system bled and free from air. Your master cylinder is "bypassing internally". Best repair is always replacement with a new master cylinder. OEM cylinders are no longer available. There are masters from other sources that can be adapted.
- Brake pedal goes to the floor SLOWLY, reservoir level goes down, no apparent leaks. It's leaking at one of the servos. Pull off the vacuum connection and look inside. OEM servos are no longer available. Lockheed ones can be fitted. Servos can be removed greatly simplifying the brake system. You would need to switch to a 0.70 master. Triumph Spitfire ones are adaptable without too much bother.
Unless your Europa is a trailer queen, I do not recommend overhauling master cylinders, servos and rear wheel cylinders. 35 years of experience with only a handful of problematic new masters and countless numbers of failed "overhauled" masters and servos. Even once had a Sunbeam Tiger with a rock hard pedal and virtually no brakes. Someone had "overhauled" the servo and put in a key component backwards. The servo was feeding pressurized brake fluid BACK to the master rather than to the wheels. That was a real sphincter pucker-er to drive.
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My car has had the twin servos removed before I acquired it.
The brake pedal always went to the floor, I am in the process of recomisioning the car.
I cant see any leaks anywhere, and I did wrap some tissue paper around the rear wheel cylinder fittings after putting in new ones to make sure there were no leaks.
When I bled the brakes , I had to top up the reservoir as the level went down. I know I need to bleed the system properly once done,I just bled them as I progressed, in order to check for air and the condition of the old fluid.
I do not intend to split the front calipers if the bores are good.
Finally I think this may be a direct replacement for my master cylinder but I would appreciate confirmation from those who know more.
https://rimmerbros.com/Item--i-213689ttps://rimmerbros.com/Item--i-213689
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I should clarify the pedal only goes to the floor when I press it,otherwise it stays up in the normal position.
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Yup, GMC226. Here's a previous thread on fitting one:
http://www.lotuseuropa.org/LotusForum/index.php?topic=138.0
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I should clarify the pedal only goes to the floor when I press it,otherwise it stays up in the normal position.
If you rapidly pump the pedal, does it still go down every time or does the action of pumping it give you some sort of resistance & reduced travel ? I'm just wondering if you've got all of the air out of the system, something which I've had trouble with on occasion.
Brian
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Question to all about caliper seals, I bought a complete kit but no seals, when I took apart there were none, do they exist and where to buy and what are they made out of?
why would they sell kits and not include them? I just did the brake job and will bleed soon, hope they do not leak. Mike.
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2nd note on calipers, on all calipers I have done before there was an o ring between, but on my europa there is NOT the little indent for an o ring, both halves are completely
smooth, that is why I asked on previous note, seems some do not have an o ring, am I correct???
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No, one side has a recess and an seal.
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2nd note on calipers, on all calipers I have done before there was an o ring between, but on my europa there is NOT the little indent for an o ring, both halves are completely
smooth, that is why I asked on previous note, seems some do not have an o ring, am I correct???
I wonder if the PO took both calipers apart and put the wrong halves together. If he did, your other caliper would have a recess for an o-ring on both halves. The o-ring has a square cross section. Don’t get a plane o-ring, get the correct Girling o-ring.
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I wonder if the PO took both calipers apart and put the wrong halves together.
Can you do that? Wouldn't one brake have two sets of connection and bleed hardware, and the other side none?
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:headbanger: Good catch! I didn’t think of another reason why neither half would have the recess.
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I can't think of a reason either, unless they aren't standard calipers, though I'd still expect some sort of seal.
I think the odd boo boo is going to happen in 7,001 posts. I'm sure I've made more than you already!
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Could have too much movement in a drum. You can lightly clamp the rubber line, one corner at a time. It would rule that out.
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I think the odd boo boo is going to happen in 7,001 posts. I'm sure I've made more than you already!
Thanks for the vote of confidence, Silver! I am positive we are all trying to be helpful to each other and I am also positive that we will make mistakes from time to time. I just hope nobody's counting mine! ;D
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Have you tried to cap off the rears and see what happens.then do the fronts , then side to side?
Dakazman
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The rears have been done so no issues there. In answer to brian ,when I pump the pedal rapidly the pressure does build up but then quickly fades. I have yet to pull apart the calipers but out of curiosity pulled out the old slave cylinder pistons and whilst they were not re used, they were not too bad.
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hmm, that sounds a bit ominous. although it's a bit messy, perhaps the next step is to remove the closing plate for better access and then fit 2 bleed nipples in place of the front/rear circuits coming out of the m/cyl (assuming you are still on a dual circuit system). If you can't get a hard pedal it does point to a failed internal seal.
If it looks ok then replace the circuits one at a time and see how you go.
Another thing that did come to mind, if the previous owner removed the servos and just bridged the pipework in the engine bay then you have the complex arrangement of pipes going from front to rear and then back again for the front circuit. Lots of potential for air to get caught in a high point loop with that arrangement and if that's what you have then I would be tempted to simplify it.
Brian
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well, the reason I looked at this post was I was going to bleed my system the day after, well I tried, used the tool for it to suck the fluid , i get lots of air from all corners, no pedal, NO leaks anywhere, new units in back and rebuilt calipers in front (with no place for o ring) and I will prove with a pic later, now I am wondering if I used wrong fluid, I used DOT 3, not girling,
the new triumph master is in, I suspect that 2 things may be wrong, 1st, I did not pre bleed master (stupid), 2nd , should I have used girling on the new master I bought on ebay
this is a total rebuild car, with all new lines, I have been restoring cars for 50 years and never had this problem, note, I left the triumph top on master and make sure level stays up,
I am sure that this could not be the problem. bleed systme agin next day, get LOTS of air, really suspect bad master. but will take off and bleed it, then reinstall, really fed up and this is a lot of work. make walk away for a few weeks, this one really has me stumped. Mike.
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Pressure builds and then goes away + no leaks and no change in fluid level = bypassing master
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I have managed to remove the calipers and the bores are good, so just a very good clean and then new pistons and seals.
If I've come this far then I will have to remove the master cylinder , hopefully it should not be too difficult.