61 replies to this topic

[adam_93rio]

Clamped the flexy's, pedal went solid.
Clamped the front two, got a pedal
Clamped the rear two, got a pedal

I realise that it'll pull air through the seal to the bleed nipple. But must of had the trigger pulled for well over a minute and had less than 5mm of fluid in the bottom of it. I'd say it was 90% air coming through the pipe.

I'm gonna give it another try tomorrow.

Just for reference to save reading through the post

All the front brakes are new, cylinders have been replaced again but to no avail and new master cylinder too

[Spider]

Clamped the flexy's, pedal went solid.
Clamped the front two, got a pedal
Clamped the rear two, got a pedal

I realise that it'll pull air through the seal to the bleed nipple. But must of had the trigger pulled for well over a minute and had less than 5mm of fluid in the bottom of it. I'd say it was 90% air coming through the pipe.

I'm gonna give it another try tomorrow.

Just for reference to save reading through the post

All the front brakes are new, cylinders have been replaced again but to no avail and new master cylinder too

 

OK cheers for that.

 

Given the pedal does go solid and you can get a pedal with either fronts or rears clamped off, then it would seem to me that the hydraulic issues are behind you., as long as the pedal isn't slowing sinking, but as that's not mentioned, I'd say it's not the case.

 

I recall we went here very early on in this thread, but it's gotta be adjustment, or a cracked drum or shoes not fitting right or something like that.

 

Ah - just one similar to this I had on a mates car the other week, now I remember. He's running discs up front, but we found, even after fitting new drums and new shoes (but from the same supplier as was previously fitted), was that the rears were right on the very end of their adjustment and even then, the pedal was quite low. When we took the new shoes off and sat them with some old shoes, we found that the metal frame of the new shoes was slightly smaller than the old, by about 2 - 3 mm. We fitted up those old and half worn shoes. We then got good adjustment and a good pedal.

[lrostoke]

easiest way to check if its brake adjustment is to adjust all shoes so they are solid on the drum. wheels wont turn..

 

Then try the pedal.If any good back off each adjuster so that wheel turns but with a slight rub on each shoe

[Spider]

Sorry, this one has really got to me. I've just been reading back through the thread,I found this one;-

 

 It was literally installed and bled up fine. Then in the time it took from having a nice pedal, to getting 3 wheels on, the pedal has gone. Just from sitting there

 

I'm just wondering if the front adjusters are worn out and slipping back under the tension on the shoe springs?

[adam_93rio]

Sorry, this one has really got to me. I've just been reading back through the thread,I found this one;-
 

 It was literally installed and bled up fine. Then in the time it took from having a nice pedal, to getting 3 wheels on, the pedal has gone. Just from sitting there

 
I'm just wondering if the front adjusters are worn out and slipping back under the tension on the shoe springs?

Ive been through the adjustment process many times now also and as far as I recall, the pedal will still go almost to the floor, but pump up solid. This is why I was thinking that the problem was still hydraulic.

The front adjusters shouldn't be worn out, as they are all brand new. The car literally has been round the block (carefully) since these brakes have been on as a short test. It can't be driven like this. But the brakes will lock up amazingly on the second pump if you 'slam on'

[lrostoke]

What you describe with the pump sounds like adjustment.

 

I changed my drums to 7.5 discs because of the adjustment messing around.

 

I used to literally have the brakes rubbing with a fair bit of friction to get a good pedal.

 

The rears I wind the adjuster in until the wheel locks then back off a quarter turn.

 

I seem to remember the adjusters at the front could push the shoes if if turned in either direction far enough.

I turned the adjusters passenger side anticlockwise facing the wheel, and drivers side clockwise facing the wheel

[Stiggytoo]

Are you adjusting the brakes with the wheels on or off?

[lrostoke]

I've not read all the topic, but did you use an eezibleed.

 

Something Ive noticed with those is you don't always get the best pedal even though the air is out..I don't know why..

Always seem to get it better if after using I just do one corner manually.. With somebody pressing the pedal.

[adam_93rio]

I've bled them with an eezibleed kit, with this new compressor vacuum kit, and the classic up down manual way. Nothing has helped the pedal.

The front drums had both adjusters wound toward the front of the car, with the wheels off, right up until the drum locks and still does the same.

It hurts my brain

[Spider]

While it did appear that there was a Hydraulic issue a couple of pages back with the Master Cylinder, and that's now been replaced and given you've bled it to death, there's now no air in the system and with the flexy lines clamped off you are getting a solid pedal, also, it can be pumped a couple of times to get a pedal, I can't see Hydraulics being part of this puzzle.

 

Sorry, but I've gotta ask. You have got the Clevis Pin fitted and correct so between the Peddle and the Master Cylinder?

 

Also, with the foot OFF the Brake Peddle, how far from the floor is it?  Can you measure this?

 

Another train of thought that I keep coming back to is adjustment. I don't doubt you and your Dad have done this and checked it a 1000 times over, but in some regards, it appears that something (???) is retracting the Piston(s) of the Front Brakes back in to the Cylinder. Could be all or even just one. Off hand, I can't think of an easy way to check for this.

 

Try Clamping off just one Front Brake and seeing how that is, Do them both, but just one at a time. Give it a few moments of you get a peddle as I've read a few pages back that you got a reasonable peddle then by the time the 3rd wheel has been fitted, the peddles gone again. I'm suspecting that something is causing a retraction of at least one of the Front Pistons but doing so with little force, hence the time that it takes for this to occur. The Residual Pressure Valve (that's in the Master Cylinder) would slow down the flow of low pressure fluid back in to the Master. 

[lrostoke]

Which master cylinder have you got, and what size front cylinders and rear cylinders.

 

I just noticed the the earlier models used smaller cylinders up front, maybe a combination of cylinders not matching master .

 

Just had this mismatch problem on mine rear cylinders to small to give enough braking at rear.

[adam_93rio]

Just had the mot on it today, and the front brakes had a good reading, not so much on the back, (just enough for the weight of the car though) so we're going to service the back as I'm suspecting the back brakes are possibly worn down enough for the adjuster to help. And it's only that we've now got extra wheel cylinders on the car that it's a problem.

Or something like that.... They do work and they do lock the wheels. It's just a bit scary that the pedal moves that far. My dad followed me to the test centre in it so we could drive a bit safer, and at least I knew not to brake hard or late just in case

So, back brakes will be changed then I will update again.
Thanks for all the help so far guys!

Mini passed with flying colours, not a single problem

[timmy850]

You say that both front ones were adjusted towards to front of the car. I've always been told to adjust them tighter in the direction the wheels rotate.

[tiger99]

If you turn the adjusters the wrong way you get exactly the symptoms described, very long pedal travel. I did that once. The adjuster pushes the shoe sideways so that it rubs partly on the drum but has a large gap at the other end. Turn the correct way and the shoe moves outwards.

I strongly recommend taking both drums off and adjusting first one way and then the other, as a second check that they are being turned in the correct direction. All will become very obvious when you see the adjusters in action.

From memory, but please be very sure to double check, the adjusters need to be turned in the direction of forward wheel rotation, which is clockwise on the left wheel, as you view the adjuster, and anti-clockwise on the right wheel.

[lrostoke]

Agree with Tiger he confirms what I posted about adjuster direction further up.

 

Like mentioned earlier try adjusting the rears so that the wheel locks, then back off a quarter turn. adjust with wheel on it gives more leverage.