Brakes not working

[stag36587]

Are the brakes adjusted up HARD against the drums ?? And does any air come out when you bleed them?

Yes...and... No. No sign of any fluid leaks anywhere either

[bmcecosse]

Take drums off and look - maybe the adjusters are sticking against the shoes - and the shoes still far away from the drums.... At the rear (but I know - you tested it and it was fine) the handbrake cables need to be slackened off, then the adjusters wound up - and then the cables adjusted...

[diggerjones]

Had a landrover once, the only way to get the brakes bled was clamping the hoses.
If I were you I would clamp front one's and bleed back, then take one clamp off front and bleed then the other side.
It may give you a pointer where the problem is.

[bmcecosse]

And ruined flexi pipes .....

[kennatt]

I refer you to my answer regarding clamping some time ago.

The master is fine,if you blanked off the front system and got a hard and solid without sinking pedal,this also indicated that there is no air in the system from the master to the rears,and that the rears are probably adjusted ok. The problem HAS to be in the front. As long as you don' t have braided front hoses,clamp each hose,test brake. If hard pedal ..no air in system up to wheel cylinders. Take one off do it again..........if hard fault in the other side swap side and recheck etc.
If the hoses are braided then there is a very ,repeat very slight chance of damaging the braiding,
If the hoses are old ,you should be changing them anyway,
If new there is NO chance that clamping,bearing in mind that they only need to be nipped up enough to close off the hole, will cause any significant damage.
If there was ,the sykes pickavant brake hose clamping tool,would have been removed from the market years ago.
We have used them in our family garage for 20 years and have never caused any damage to, or had any repercussions after. Use mole grips on a low setting with 50 coins on both jaws to replicate the pickavat tool. Its standard practice in all pro garages.

[DAVIDMCCULLOUGH]

I cant recall wether Ive suggested to you before of raising the car either back or front and leaving pressure on the pedal overnight? I have found this to work before when all else fails.

Pity I wasnt a bit closer or I would come round and lend you a hand!

[stag36587]

Yes David you have - did that but alas no improvement. You'd be very welcome to drop by any time you are on the mainland I live about half an hour from Kelmarsh. Kennatt, flexible hoses are new non-braided replacements from ESM. I'll clamp them in next few days and see what happens

Thanks for everyone's replies so far.

[mowogg]

Just reading through the thread, i have had similar issues in the past and found a couple of pointers.

if you change all the brake shoes at once, and install new cylinders the brakes feel very spongy until you have driven it to bed the shoes in. I re-bled a system several times before I dared venture out, but they soon improved in a very short distance. I assume this is due to a poor fit of new shoes onto used brake drums.

I found i had a air bubble stuck in the T section where the brake switch is. in my experience this is not removed by bleeding.To remove this bubble, I slackened off the switch and bled it directly. This took me some years to find, and it resulted in the peddle dropping considerably further when first applied after a period of non braking. The car past a number of MOT's like this but feels much better now this has been removed.

I wonder if you have a combination of these 2 contributing to your problem?

[stag36587]

Thanks Mowogg, You might have a point about bedding in the shoes. I have previously bled the brake light switch (also new).

So in a cold garage today this is what my son and I managed:

Clamped the flexible hose (nearside front) and found no difference in braking operation - brake pedal firms up after 2-3 strokes.

So, took nearside front drum off and asked son to press brake pedal - I could see clear movement from the front-most brake cylinder, but nothing at all from the other cylinder until adjuster backed off. Made sure both adjusters were set at tight minus one notch and bled that side of the car only. A small amount of air came out but no difference to operation after bleeding

Next, I disconnected the nearside brake pipe from the 3-way union in the engine bay and fitted a dummy union, I.e. isolating brakes to front offside only. Still no change to the brake operation which seems to suggest the same problem is affecting both sides.

Grateful for any further ideas?


Thanks

[bmcecosse]

All adjusters up TIGHT! After checking they are not sticking against the shoes - causing a false setting...

[mowogg]

I have heard of air locks developing within the brake shoes which is not to surprising when you look at the configuration. The flexible line comes in the top, and the air bubbles have to be pushed down through the connector pipe to bleed effectively. the air will want to come to the hiughest area, and not be pushed downwards

it might be worth undoing the 4 bolts that secure the back plate and rotating the back plate so the inlet side is at the base of the drum and rebleed. Air can then go up, and can be bled effectively?

[les]

That's a desperate measure! Plus you'd distort the brake pipe. Perhaps you need to try an ezybleed kit, which pushes fluid through under pressure,.

[bmcecosse]

I just use Gravity - it's never failed me so far......

[kennatt]

What happened when you clamped the offside ,if no improvement when you clamped nearside then problem is in the offside. Clamp both fronts and try pedal,take one off and try,put it back on and take other one off and try.

[mowogg]

I think my suggestion has been misinterpreted above. I was suggestion that you under the four bolts holding the backplate to the kingpin and then rotate the back plate around on the axis of the stub axle. if you turn the steering appropoaitly lock i am sure you can free up enough flexi hose length to do this without any issues. You can then position the system to allow the air bubble to rise upwards as you bleed the system as opposed to forcing it downwards in a pipe. It possible the air bubble is sitting in the top of the cylinder, allowing brake fluid to pass, staying untouched by the bleeding process

[bmcecosse]

There can't BE a bubble of any significant size in the pipes or cylinders.....

[stag36587]

What happened when you clamped the offside ,if no improvement when you clamped nearside then problem is in the offside. Clamp both fronts and try pedal,take one off and try,put it back on and take other one off and try.

No difference whether both or either side clamped - I wonder if the 3 way union is faulty!

[bmcecosse]

If fluid comes out when bleeding...it can't be faulty... Can we confirm how you are bleeding? With an assistant - pumping up the pressure then you snap the bleed valve quickly open and close... And only then does he/she allow the peddle to rise ? And the shoes are all adjusted up as hard as you can - dragging ?

[stag36587]

Yes Roy I'm bleeding them correctly exactly like that

[panky]

I had a very similar problem with my Mini. I had the hubs off overhauling the callipers but when I tried to bleed them the results were just as you describe. After weeks of bleeding, 5 litres of brake fluid, a new master cylinder (that I didn't need ) the penny finally dropped - I had fitted the callipers on the wrong side of the car so the bleed nipples were at the bottom As soon as I swapped them back to where they should be the brakes bled fine and worked perfectly. I would have thought that the bubble trapped in the callipers would get flushed through but it didn't so I recon you have the same issue with a tiny bubble trapped between the flexy and the cylinder - so the idea of swinging the hub round on the flexy might be an idea to try.