Bleeding brakes when valve end rounded

[sharkjazz]

Hello,

Had a bit of an issue where the brake fluid was one day below the minimum mark. Couldn't see any obvious signs of leakage, so tried to fill up the reservoir and bleed out the air.

Both rear values were slightly rounded and the oversized adjustable spnner I used appeared to do more damage. Now I have a 7mm (that worked perfectly fine on the front) doesn't fit the rear wheel bleed valves. Have tried a 6mm (clutching at straws) and it too doesn't fit.

Are there any tricks for opening the bleed valves?

I also tried some pliers, again no luck.

I have tried bleeding the front types 4 times now, each time air comes out the first time the pedal is pumped and depressed, then just fluid. Then about an hour later, more air will come out. If I just repeat this enough times would all the air be drawn out?

[CovKid]

Yep. I learnt this the hard way many years ago and always do bleed nipples the same way now. Use molegrips (good ones) to actually move them THEN switch to spanner. 9 times out of ten it works. On the back, if they break despite all attempts, just swap for new wheel cylinders - they're not that much.

And yes, you do have to repeat until (ideally) you get clear new brake fluid through.

[itchyfeet]

Fluid loss can be from the clutch slave cylinder as they share a reservoir well but if you bleed the front brakes and air comes out then there is air in the brakes so that needs fixing.

There is no easy way other than getting the rear bleeds nipples out and replacing them, if they shear off you will need new cylinders.

use a good penetrating oil such as plusgas if you can get it, leave it to penetrate overnight and then use mole grips, gently at first if there is no movement you might try some heat with a blowtorch but not too much or you will dmage the rubber seals.

I have to do one of mine at the weekend, the replacement nipple is 7mm a/f