Welcome to our resource for MG Car Information.
MG Midget and Sprite Technical - Bleeding brakes
Unfinished car needs a tow to the garage to fix the chassis. Brakes need a bleed after the master cylinder and main line to the 4 way union were removed, and both rear drum cylinders renewed. Done the usual stuff with all the nipples and a tube/NRV/container arrangement but still getting a soft pedal. Didn't notice many bubbles coming through. Is it simply a case of pumping until they do - especially in the rears considering the length of line any potential air has to pass through?
Also - handbrake on or off?... can never remember. Fronts are Wilwood calipers by the by - 2 nipples on top. No bubbles here when bled either....
|Handbrake off, and borrow an Easibleed! Makes it so quick and efficient.|
|If you cannot borrow an Easibleed, then buy one! You won't ever regret it!
And if you cannot buy one . . . .
then improvise with an old bicycle tyre inner tube. Cut the circle of the inner tube around 12" from the valve and fold that end over a couple of times and secure it with a large bulldog clip to make that end air tight. Brim-full the mastercylinder with brake fluid and stretch the other cut end over the filler cap. Pump up the tube so it swells like an over-fed python to pressurise the system and then bleed the brakes, starting with n/s rear. Only thing is you must be careful not to bleed too much fluid through without removing the python and refilling the M/C.
When removing this humorous looking python, release any pressure by depressing the valve core pin first to avoid splattering brake fluid around the engine bay paintwork ;-)
|That won't work on a dual master, will it, Guy? Not much neck.|
|Nick and Cherry Scoop|
|No, I guess not. Unless you happen to have one of those super-rare extension tops and can stretch the python over the whole of the casting. It is quite fun to do though!|
I used the method years ago on a mini - I think it was before the Easibleeds were invented.
|As a matter of fact, my Easibleed came with no cap suitable for a dual master. I modified it with a spare m/c lid and plenty of plastic padding, but shrinkage took its toll within the year. It hangs there now, looking resentful, and I may revive it.|
Has anyone used a standard easybleed on a dual successfully?
|Nick and Cherry Scoop|
|My Easibleed came originally with a little bag of metal screw caps which over the years have deteriorated. Its not hard to make replacements with plastic caps from scrapyard cars, drilled to take the pressure tube and fastened win place with a couple of fibre washers either side. Later style caps on modern cars that have a built in fluid level indicator are harder to modify because of their irregular shape. I have used it on all sorts of vehicles. Its a bit of a bind swapping caps over but a lot easier if you keep it unsullied and solely for use on your Spridget.|
|not sure if its any better, quicker or more reliable, but the garage i occasionally borrow a ramp from, use an airline and the vacuum technique. . . .anyone else tried that ?|
|Thanks Guy. I wish I knew where there was a scrapyard. Maybe my local garage can help. |
As for my modification, it's quite a bind unscrewing the five screws of the m/c lid and screwing the modified one in place, with the risk to the cork gasket.
I see that the new eezibleeds have what look like decent plastic caps, unlike the rather flimsy metal ones you describe, which came in my original set too. I might take a £19.99 punt and buy a new one.
|Nick and Cherry Scoop|
|My only other grumble with the Easibleed is that the Easibleed bottle uses a different thread to that commonly found on 1 litre bottles of brake fluid. Its much the same size - just a different thread. If they used the same thread then one wouldn't have to decant fluid from one to the other and risk adding air bubbles in the process. One could also then just leave unused and uncontaminated fluid in its original bottle, replacing the standard cap and store it till next time.
Fluid should be available in a choice of colours so when bleeding a system you can vary between one session and the next and tell when the fresh fluid has arrived at the bleed point.
I used the easybleed on my dual master cylinder to bleed the clutch when gaps engine and gearbox was recently transplanted into the new frogeye. Worked perfectly as usual and I wouldn't be without it. I run it off the front tyre eitjout any problems either.
|Is yours a plastic caps model, Gary?|
|Nick and Cherry Scoop|
|The easybleed is metal cap and the master cylinder is plastic cap|
|Pleased to see other people have had better experiences than me as I didnt get on with Eezibleed at all on my dual master cylinder. |
The plastic cap didn't seal properly and so fluid spilled out everywhere. When I tightened the lid up, it cracked.
I now use SWMBO and bleed the old fashioned way. Works well enough for me.
|Another vote for the Eezibleed, mine came with the plastic caps and I was surprised how good it was for £20.|
|I used the Eezibleed many moons ago - hopeless. Didn't seal on the M/C at all well despite a variety of fittings. I have since tried the python, secured with a jubilee around the neck of the M/C. Many thanks again, but although now much improved, still somewhat spongy - no bubbles coming from the nipples. Do I wait a day or so for things to settle and try again?|
|Oggers, that's what I do, But then I think that it is the vibration of using it that shakes the trapped air out to coalesc into bubbles that can then be bled.. I take it that your car still isn't ready for use again? |
Maybe any air would rise anyway. I've no proof that my theory of shaking the air out is actualy what happens though the brakes do seem to firm up better when bled again a few days later.
|I've had quite a bit of success just opening one bleed thing at a time and leaving it for about 10 mins dripping away, keeping the MC full.|
|After reading these posts about all the problems people have bleeding brakes, how many people clamp of the nearest flexible pipe to where they are working, e.g. you are changing a front wheel cylinder/calliper and you clamp off that flexible pipe, you wont drain out all the pipes on that side, or if you are to slow perhaps most of the fluid in system, then after you have changed the wheel cylinder /caliper, if you don't get a good pedal, you will know which corner is at fault, and you don't need to go chasing round the system bleeding the other corners, if you are removing/refitting a master cylinder or front to rear pipe, clamping the flexible's has no effect, another thing to think about if changing a master cylinder or a servo, is to bleed that unit first and not push the air in these round the system, sometimes when changing these components you can get away with just bleeding them alone and get a good pedal, with reference to Easybleed, if you use a pipe clamp, by the time you have set up your easybleed you could have already done it. |
|Good point Andy. I've got braided hoses so pipe clamps are a no no, but I also have some pretty squeezed copper bits I can quickly screw into open hoses.|
|Ummmm braided hoses I think the least said about them the better, the other thing you can do is take the top off the master cylinder,take a plastic bag place it over the hole and screw the top back on, if you get a good seal that will stop the fluid loss.|
|what do you perceive as wrong with braided hoses Andy?|
|David. There is no benefit to be gained in fitting these to a standard production vehicle, they cant be clamped off, for brake problem diagnosis, and when working on the system, service inspection of the inner pipe is impossible, they are expensive, the only advantage with having them is you can bore people to death telling them all about them, if your braking system is in good working order correctly serviced and maintained, I am of the opinion that you couldn't tell if they were fitted or not,|
|I did have a problem with a braided hose (clutch not brake). It somehow got slightly frayed and one if the wires punctured the hose. Trying to drive home in central London with no clutch was a challenge.|
|Aha, having qualified it with standard production car, I agree with you.|
the important factor you've left out is modern made piss-poor rubber parts. IF the rubber brake hoses are not the same as many other modern rubber parts have been/still are(?) then the rubber hoses offer the advantages. But having put many modern made rubber parts on my car that only last weeks or months before they perish (or wiper blade elements useless from new) I'd not trust modern made rubber brake hoses unless a lot of users reported they were now good.
BTW are you still on for an E-clip demonstration or challenge?
|Defiantly Nigel just let me know when you are coming for this demonstration, I might even buy a packet of biscuits, to have with our tea, it will only take about 5 seconds to show you.|
|Andy, cheers, tea is our language (along with pee stops now) but I'm not allowed biscuits as I eat too many (usually half a packet at a time).|
If you could email me, or other way round, we'll see if we can get this sorted.
my first and last name at bt internet dot com (names joined, no other dots or numbers).
|I use SS braided hoses, but I think their main drawback is that you cannot see the internal hose to inspect it. So unless you follow a strict age-replacement policy you have no way of telling how close to catastrophic failure you are. There have been cases of the inner pressure line blowing out of the end fittings.|
|Well, my easibleed was waiting for me when we got home yesterday, and today I decided to fill my brand new but empty system and try it out. |
Good news:- it fitted and was fluid-tight.
Bad news:- After bleeding I haven't got a pedal.
What's next? Assume air and go round again? I suppose the way to check if there's something amiss in the master cylinder is to enlist the attractive assistant and see if pedalling moves fluid.
|Nick and Cherry Scoop|
This thread was discussed between 18/04/2018 and 25/04/2018
This thread is from the archive. The Live MG Midget and Sprite Technical BBS is active now.