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MG Midget and Sprite Technical - My bleeding way!

Hi chaps
I was bleeding my brakes and clutch and thought I would share my method as I have not seen it mentioned before.
My method involves using a 4 M long piece of tubing and two tube clips (like those used to clip sandwich bags).
Attach one end to the bleed nipple and place the it other end into the top of the relevant master cylinder. Make sure some of the pipe is visible when you are sat in the driving seat.
Now undo the bleed nipple ad gently pump the pedal. The fluid is pumped up the tube from the nipple to the master cylinder. You may need to top up the master cylinder resevior at this point.
Now keep pumping until no more bubbles come past you in the tube.
Close he bleed nipple.
Clip the pipe at bothe ends and transfer to thenext nipple. The clips stop fluid getting everywhere.
The method make sure there is no air in the system and also reduces the wastage of fluid (important if like me you are using costly silicone).
Bubbles coming through the tube tend to float to the surface when try get to the master cylinder self purging the system.
Hopes this helps someone
Cheers
Tim
T Dafforn

Good to know. However I've found Easybleed to be unbeatable.
frogeye Gary

The problem with that, as has been discussed here multitudinous times, is that "regular" brake fluid is hydroscopic. This is why you are advised to change all the fluid in the first place after a persiod of time. Just circulating it in the system as you suggest, doesn't remove the water.

Even stored in a sealed can long enough, new brake fluid is said to absorb water. So although your "salvaged" brake fluid might look clean and clear, it will almost certainly contain water if it's been in the system long enough. And if it contains enough water, it'll reduce the effectiveness of the brakes, maybe even to the extreme that one day it will boil, and you won't get any brakes at all. That's apart from any corrosion the water is causing in the cylinders and calipers. :). So not a good idea for most I reckon.

Not sure if you can recirculate silicon fluid though, as the water drops out of that.??

Lawrence Slater

SILICONE BRAKE FLUID (DOT 5)
Silicone based DOT 5 was originally introduced to give higher temperature performance over glycol DOT 4. Silicone fluid also has other advantages, it does not damage paintwork and it does not absorb water. However, silicone fluid is a poor lubricant and does not lubricate ABS pumps as well as PAG fluids. It is also more compressible than PAG fluids, which can result in a sluggish or spongy pedal. It therefore requires special design considerations in braking systems. Further, because it does not absorb water, any water remains as globules, which can pool in low spots in the system and cause corrosion. This water can vaporise when heated under heavy braking giving a disastrous effect on braking efficiency.

DOT5 fluids are not recommended for motor sport applications.

http://www.opieoils.co.uk/pdfs/tech-articles/Brake-Fluid-Explained.pdf
Lawrence Slater

All modern cars have a servicing programme which recommends complete renewal of the brake fluids - usually every 2 years. And this is of course with silicon fluid. So the same applies for silicon as Lawrence describes, - probably not a good idea to just keep recirculating it.

Partly for this reason, I stick with basic DOT 4 fluid and change the lot every two years. At �9 to flush the system through every 2 years its cheap enough, and if it has to be changed that often anyway then it seems to me that the principal benefit of Silicon of not being hygroscopic is largely lost anyway.

I still think fluid should be made available in a range of colours though. That way you could see when last year's outdated colour was all flushed out and this year's in colour was, um, in. As I did this job with my brake refurbishment last week, I was even musing on whether to add a few drops of soluble food dye to the new bottle. But I chickened out as I wasn't sure it wouldn't somehow react with the DOT 4.
Guy W

Sorry chaps,
I should have been a bit clearer.
I use this method either on newly rebuilt systems or after draining the like fluid out.
I agree there is no utility in merely cycling old fluid.
For new systems there seems to be a lot of chat on various car restoration sites about inability to remove all the air from a system. This includes people discribing using litres of fluid during bleeding. This method seems to sort that.
Regarding silicone fluid. I know it is contentious but I had been using it in old cars for 15 years and it seems ok. Mind you I have only used it in systems that we're completely rebuilt first.
Cheers
Tim
T Dafforn

And I mis-spelled it anyway. As Guy said, it's "hygro"scopic, not "hydro"scopic, which is about the observation of items below the surface of water.
Lawrence Slater

Hi Tim,
I wasn't meaning to rubbish it as a technique for simply removing air bubbles. Although I have never had any difficulty with more standard techniques! I occasionally will top up the M/C with fluid that has already been pumped through, provided that it is new and has also been left to stand overnight so that any microscopic air bubbles can rise to the top and escape. So I guess that comes to the same thing.

As regards silicone fluid, I agree there is nothing wrong with using it for old cars. Its just that if you plan to change it at the recommended 2 year interval, then you may as well use the cheaper DOT4.


And if Lawrence is correcting his spelling of Hygroscopic, I should also correct mine and refer to the correct type of silicone (not silicon)
Guy W

Here's an idea that I used to do before I lashed out and bought an Easibleed. Actually it was before I knew that Easibleeds existed.

I got a plastic bottle of some sort. Not the thin water bottle type but one of the chunky household cleaner ones. Cut the bottom off, invert it and screw the neck of the plastic bottle down onto the neck of the brake m/cylinder. The plastic deforms to form a thread and makes a leak-proof seal to the m/cylinder. You then have a much increased m/cyl capacity and can fill up with brake fluid. This itself makes bleeding easier as you don't need to keep topping up and the increased head will push fluid through without the need for pumping the pedal. When finished, remove the surplus with a syringe back to below the filler neck before removing the bottle.

I used a further addition which was to fit a length of bicycle inner tube, with valve, over the end of the bottle. Cut a bike tube and stretch one cut end over the end of the bottle. Folding the other end over a few times and a bulldog clip makes an air tight seal. Pump the tube up via the valve with a bike pump. You now have a system that does the exact same job as an Easibleed.

Guy W

Hi Guy,
Sorry, didn't mean to give the impression that I thought you were :-).
Also have an easy bleeder and it is great. Although it's just a pain having to collect the fluid that runs through on bleading. I'm just lazy!
I also wonder whether with new systems bubbles form on the surface of the tubes as the fluid struggles to wet the new components? Seems to me pushing volumes of fluid through the system has to help knock these bubbles off. I know the new system in my midget didn't bleed well first time with the speed bleeder. Had the luxury of leaving it for a few weeks and the pedal firmed up somewhat.
Then flushed through with the long tube method and saw a number of 1 mm size bubbles come through. Pedal seems nice and firm now.
Inner tube and plastic bottle methods sound good.
My liking for silicone comes from a number of incidents in the past with glycol fluid and paint.
Tim
T Dafforn

Yep, Glycol fluid and paint don't mix well! - Or to be a bit more accurate, they mix all too well!

I always find that I bleed brakes twice. First time gets them working OK. This is followed by a couple of day's use. Driving over bumpy roads and then allowing to stand over a couple of nights seems to dislodge additional air bubbles and allow small microscopic bubbles to coalesce. Then a second quick bleed gets rid of these too and the brakes then really firm up well. Always works well for me.
Guy W

Guy: I would be very wary about playing around with makeshift pressurised bottles! You obviously had no problems but one slip and pressurised fluid spraying everywhere can cause havoc with paintwork. It can happen with Easibleed if care isn't taken and that is made for purpose. I always cover the bottle and the mastercyl with a towel "just in case".
Graeme Williams

Ah yes, Graeme, but I like the excitement that it brings to life!
Guy W

Guy

"I still think fluid should be made available in a range of colours though"

I does!

I use ATE DOT 4 SL.6, Which is a amber coloured high boiling point fluid.

I alternate with ATE Racing Blue, Which is exactly the same spec, but blue..

I get it from Euro Car Parts..
Dan Cusworth

New on me, Dan. I have been promoting this idea for several years - even writing once to Halfords (with no response). So now I know where to go for it. Just 2 colours would suffice to achieve my cunning plan. ;-) Thanks!
Guy W

Your could alway add some fabric dye. :-)
Tim
T Dafforn

My method involves a length of clear plastic tube, a glass jam jar and an obliging Wife to pump the pedal. it's served me for years enough.
Pete Ottewell

My wife isn't as obliging. Gets bored and wanders off.
Tim
T Dafforn

Tim...

Your in trouble buddy... thats how I invented bleeding brakes and clutch...in fact I was going To patant the proceedure....hahaha

On a serious note... use the clear viynal tubing, you can easily see the air bubbles circulate ...but the tubing is a one time use imho as it gets cloudy and gueyy inside


Just pump the brakes slowly to avoid adding the recycled air back into the master cly

Prop
Prop and the Blackhole Midget

Also add a little play doh or chewwing gum  at the calpier bleeder valve once its opened... some times a well used valve will suck in air by way of the bleeder valve threads

Prop

Prop and the Blackhole Midget

Sorry... I meant avoid air being sucked into the master cly. "" internals ""

Prop
Prop and the Blackhole Midget

Sorry Prop.
All I can say is "great minds think alike". I used silicone tubing which has the advantage of not going cloudy with silicone fluid.
Play dough a good idea though. Luckily all the fittings in my system are brand new.
Tim
T Dafforn

Nothing wrong with brand new fittings, and lets face it, children playing with playdoh without brake fluid contamination is a goid thing....hahaha

Yeah... I think the procedure is the cats meow, im guessing your in the same boat im in, no sexy hot looking 1/2 naked babes to crawl under the car and help out where and when needed

Yeap...we just have to resort to our own devices

Btw... it works great for bleeding the clutch as well.

One thing i do also is I bleed from the furthest wheel to the MC in that order

The great thing about the clear rubbery tubing is its like 5 cent per foot, so 15 feet is less then a dollar

Prop
Prop and the Blackhole Midget

Prop
Agreed, also used it for the clutch. Lack of willing women is indeed an issue.
Cheers
Tim
T Dafforn

Even if you have a willing wife/partner. It's not always a good idea. Just the other week I installed my missus in "the office" and asked for her to press the brake pedal down etc. after a few mins, it came apparent we were struggling to make progress.





She was pressing the clutch pedal........





God help us.
Dan Cusworth

so you've not taught her right (from left) then!
David Smith

Hahaha....

Well that was your 1st mistake.... using the wife or girl friend

20 year old collage girls are a better choice...no, they will Still screw it up,

but ...well, you know where this comment is going

Naughty girls need to be spanked, how else will they learn.

Prop
Prop and the Blackhole Midget

what's scary is she's been driving for over 20 years!
Dan Cusworth

I use a shower curtain pole - the sort that are sprung and can be adjusted to fit the opening --- just adjust it to fit between the seat and the pedal when depressed -- push pedal down with the pole and wedge it on the seat -- go and open the bleed nipple and shut it again while fluid is still flowing under pressure -- repeat till clear fluid flows without spits of air -- repeat for other bleed points if doing brakes.

Takes no time at all and you don't need an assistant or lengths of tube ( which usually fall off in my experience!)
Chris at Octarine Services

If you are using Silicon fluid then it is NOT a good idea to recirculate it immediately, as it tends to develop micro bubbles. I reuse it, but collect the bled fluid in a separet container and then store for a few weeks to let the bubbles diffuse out.

The Eezibleed is a great piece of kit.
dominic clancy

Amazing Chris. I thought it was only me that had that idea. I use a "bullworker" though. I've been using this method for over 40 years. Works a treat.

Keeps me fit and the car bled. That's me in the pic of course. lol. --- I was younger then LOL.


Lawrence Slater

And here is a current NOW photo of lawerance

Yepp... "bullworker bar sure did the trick (or treat) "...hahaha


http://db.tt/1dSUSTYi

Prop

Prop and the Blackhole Midget

That's not fair Prop. I haven't got any tatoos at all. :).
Lawrence Slater

The tats were photo shopped to hide the hairy nipples

Prop
Prop and the Blackhole Midget

I have just bought and tried the coloured fluid and it worked a treat in terms of showing when the new fluid was coming through. Unfortunately it's twice the price of plain Dot4 and as usual managed to kick over the jar of fluid so wasted a fair bit. Why do they kick over so easily?

I can also say I recently experienced Dan's problem with Better Half and cluch pedal. Still it was a relief becuase otherwise I was wondering why pumping the brake pedal didn't expell any liquid. I guess if you are not used to driving the car and getting in VERY carefully as it's balanced on blocks the right foot is in danger of falling on the wrong pedal. Ah marital harmony!
Graeme Williams

I've always found my Wife to be very obliging. For pumping that is.
Pete Ottewell

I'm not sure you wanted to put such a statement or offer on a public forum
Nigel Atkins

Already in the queue, Nigel?
Guy W

always for help with the car











otherwise I'm very happily married






although I'm not sure if my wife can say the same for her
Nigel Atkins

Gentlemen please, I obviously meant the pedal.
Pete Ottewell

and so did we Pete !
Nigel Atkins

Is it me, ... cause i feel like I need a shower...hahaha

Prop
Prop and the Blackhole Midget

This thread was discussed between 29/09/2013 and 11/10/2013

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