Brakes: Strange Brake Issues

[Roy V70 850]

Originally Posted by VOLVOBOY

The problem is that you can press the pedal down further when bleeding than when the brakes were under normal use .
If a wear ridge has formed on the Master Cylinder Piston Rod there have been instances where the Seal Lip has either been scored or reversed itself .

That's handy to know, although in this instance, from what I read, I don't think either of us used the brake during bleeding.

Thanks for the advice, I'll bear that in mind when I change the rear calipers.

[daveystoat]

Originally Posted by VOLVOBOY

but you have to ask yourself, why would the seals go just as you've bled the brakes when everything was fine just beforehand.

The problem is that you can press the pedal down further when bleeding than when the brakes were under normal use .
If a wear ridge has formed on the Master Cylinder Piston Rod there have been instances where the Seal Lip has either been scored or reversed itself .

It is a possibility, though I didn't use the pedal to bleed them on this occasion, and last time I had a chance to check the pedal had firmed up somewhat, so I would be surprised if it was the case here.

Not had a chance to do any more on it for various reasons, I am hoping to make progress in the next couple of days.

[SnineT]

Originally Posted by daveystoat

It is a possibility, though I didn't use the pedal to bleed them on this occasion, and last time I had a chance to check the pedal had firmed up somewhat, so I would be surprised if it was the case here.

Not had a chance to do any more on it for various reasons, I am hoping to make progress in the next couple of days.

How are you bleeding them? are you cracking the nipple and then pumping or pumping 3 times then cracking the nipple until fluid flows, you must keep an eye on the level as well as it's easy to run low and get air back in and start at the wheel furthest away from the servo, hth.

[daveystoat]

Originally Posted by SnineT

How are you bleeding them? are you cracking the nipple and then pumping or pumping 3 times then cracking the nipple until fluid flows, you must keep an eye on the level as well as it's easy to run low and get air back in and start at the wheel furthest away from the servo, hth.

I used a pressure bleeder, it's only me doing it.

I seem to have got somewhere at last, after much head scratching and wasted brake fluid. There was a slight leak on the n/s rear where the pipe and Flexi hose meet. All now sorted.
Basically, I have re-bled all calipers, starting at the n/s rear. After each one, started the engine and pumped the brake pedal a few times. It's now a little spongy (likely to settle down IME), but doesn't go to the floor, and no air bubbles in there at all, also, fluid doesn't seem to be going down, but I will keep an eye on it before I attempt to drive it.

[john f]

It might sound silly but the spring pad retainers need to be installed correctly
I changed my front pads and the brakes were very spongy I bled them numerous times and still poor
I had fitted the retaining spring incorrectly 5 mins later ,solid pedal I couldn't beleive this spring could have such an influence


John F

[daveystoat]

Originally Posted by john f

It might sound silly but the spring pad retainers need to be installed correctly
I changed my front pads and the brakes were very spongy I bled them numerous times and still poor
I had fitted the retaining spring incorrectly 5 mins later ,solid pedal I couldn't beleive this spring could have such an influence


John F

Hi John, yes, I have noticed that before. Get them wrong and the brakes actually feel scary. Amazing the difference they make. These are ok though :-)