Brakes. What im i doing wrong ???

[gammy126]

Hi all . Iv just started doing little jobs on my moggie even though iv had her 2 years. Not had the confidence before now and iv just got some imperial spanners etc of ebay , so i decided to bleed the brakes as there was a lot of travel on the pedal and they wouldn't lock at 20mph when braking hard.
This is what i did so where did i go wrong ???

Read forum advise on bleeding brakes.
Read Autodate book on brakes.
Loosened all wheel nuts , removed wheels and put safe on axle stands.
Release hand brake.
Tighten up brakes using adjuster , so all wheels are tight.
Remove carpets to expose Master cylinder .
Top up master cylinder with DOT 4 synthetic brake oil.
Un nip rear passenger brake nipple, put grease around base attach breath hose put in a clear 500ml pop bottle and fill with fresh brake fluid so the end is submerged. Press brake pedal up and down watching for bubbles when bubbles stop tighten nipple. Then repeat driver side rear, passenger front then drivers front.
Un do adjuster 1 click on all wheels.
Attach wheels, remove stands, lower . tighten wheels.

On test drive they are worse than before and wont stop at 10 mph.

All help advise most welcome as i don't want to take it to ATs or Kwickfit as i cant afford to do so.
Many thanks
Alan

[mike.perry]

Sounds alright in principle but if it is the first time that you have bled the brakes then I would stick to the tried and tested 2 person method, one on the pedal, one on the brakes. Press pedal, release valve, tighten valve, release pedal. No more than 6 pumps between topping up the master cylinder.
Do not road test it whilst there is still excessive pedal travel

[Trickydicky]

Hi,

As mike rightly states use the two person method, always works for me (now I have the wife trained properley in the art of bleeding brakes)

You say in your post that you have used synthetic fluid, do you know if you had mineral brake fluid in there first and now you have mixed the two? (synthetic and mineral)

I do belive that mixing the two together is not advised. (I am sure others will correct me if I am wrong though?)

Richard

[gammy126]

Hi Richard
Thanks for the advice . No idea regarding the oil that was in i just got some Dot 4, iv used a full 500ml bleeding so i assume what was in is now flushed out.
To elaborate more a few months ago i borrowed my moggie to my x as her car was getting repaired. On getting it back the brake pedal was sloppy and right to the floor with no braking at all.
On getting her home ( the car not my x) i checked for fluid loss but couldn't find any as the M /C level was OK. I did notice that the yoke on the brake pedal was bent so i ordered a new one along with a brake return spring.
I removed the M / C to check the seals and they looked fine, installed the new Yoke, plunger and spring and M / C then bled the brakes. With the same dot 4.

The other week on the way to a show my brakes started binding and the pedal was solid, when i got to the show i was told that there wasn't enough play in the pedal and the fluid wasn't returning in to the M / C, so i backed off the nut on the yoke and wound back the plunger just to get home .
That is why i have bled the brakes today in case there was any air in the system.

I know the brakes aren't brilliant but I'm sure they should be better than what they are.
Perhaps i need to have a drive in some one else's Moggie to compare, It might just be me at the end of the day, But surly you shouldn't have to have your foot to the floor and pray every time you come to a roundabout.

Thanks for your input so far.
Cheers
Alan

The more i look the more i find what wants doing.

[Trickydicky]

Hi Alan,

The manual says you should have 3/4" free play at the top of the pedal before the plunger on the M/C starts to operate. When you bled the brakes are you getting clean fresh fluid through? from the symptoms you describe there must still be air in the brake lines, my brake pedal is nice and firm, takes up the 3/4" free play then immediately firms up with no sinking when you keep it pressed.

I recently replaced my M/C and found I could not get the brakes to bleed,(it was bleeding frustrating ) I read in a book to start bleeding at the drivers front brake then the passenger front brake then the drivers rear brake, and finally the rear passenger brake untill you get fluid flowing from each with no bubbles, using the two man bleeding method as Mike described earlier (make sure that when the pedal starts to be depressed you open the bleed screw, then when the pedal is at the botoom of its stroke you lock it back up before allowing it to come back up.).
Then go around each wheel as per the sequence in the manual, a couple of presses of the pedal at each wheel will be enough, you should then have a firm pedal.

Good luck!!

Richard

[bmcecosse]

Were you getting any bubbles out with the bleeding?

[kennatt]

if you pump the brake do you then get a hard pedal

[gammy126]

Yes there where a lot of bubbles out when i bled the system mainly from the back. And no it doesn't go harder when i pump.
Ill give it another go today and get some one to pump the brakes.
Thanks for you help so far.

Cheers
Alan

[mike.perry]

Keep pumping and topping up the master cylinder until all the bubbles have gone from each cylinder. The brake pedal should be firmer when you have pumped the air out of all the cylinders and all the bleed valves are closed.

[bmcecosse]

I just let gravity do the job - too hot for pumping today.......

[gammy126]

Your right it to hot to pump anything, thats why iv not done it yet. What do you mean by let gravity do the job ? im i missing a trick of the trade.

thats not oops it just sun burn.

[bmcecosse]

Tube in jar with fluid - open the valve - pedal down once then slow up, and sit back under the shade tree with a cool drink watching the bubbles dribble past......

[gammy126]

I like that idea , will definatly give it ago tomorow . Cheers for the advise.

[bmcecosse]

Some say it only works in ecosseland - but then we do seem to have stronger gravity.......

[gammy126]

Well I Bled my brakes again and still more air came out , especially at the front passenger side.
It was a two man operation this time. Bled front drivers then front passengers then rear drivers then rear passenger.

Then again rear passenger, rear driver , front passenger , front driver then repeated the latter again . No great improvement still only start braking in the last 1/2 3/4 of pedal . All the fluid looks clean and i put another 750ml through again today.

What next , Do i replace all the flexi pipes as they look old and probably original , then replace the M/ C or do i just get a overhaul kit.

Or is it normal for a moggie and I'm being paranoid .

All comments welcome .

Cheers
Alan

[bmcecosse]

Are the brake shoes adjusted up hard against the drums ? And how much free play is there on the pedal ?

[gammy126]

Yes all where adjusted up hard before bleeding and i might get a little back on the free play but i had to unwind the piston rod last week because there wasnt enough free play and the brakes where binding.

[bmcecosse]

I don't understand where the air is getting in - won't be the flexi pipes (but not a bad idea to renew them anyway). Try bleeding with the method of pumping up the pressure - then quick open/close of the bleed nipple. This makes sure no chance of air being drawn back in the bleed nipple threads on the 'up' stroke...... If that still doesn't work I'm afraid you do need to consider a knackered master cylinder.

[gammy126]

Just took her out for a proper test drive and the brakes firm up if i pump them once or twice , does that mean there is still air in the system ????
Looks like im off to buy another Ltr of Dot 4.

[bmcecosse]

Either that or the adjustment is too slack...... If you can drive it - they can't be 'hard up'! You can reuse fluid provided it's not the horrible old original stuff - as long as it stands long enough to let all the bubbles rise up and disappear....but don't let the atmosphere get at it since it soaks up moisture...... Have you tried the pump up - quick open/close yet ?