Xc60 brake failure help!

[Kugaman1]

Hi,
We just changed the front discs and pads on my 2020 xc60.

Decided to bleed the brakes.

On opening the bleed nipple - car (which was turned off) gave an abs type pumping as soon as brake pedal was touched and forced fluid out of nipple. Tried again and same again. Don't believe the brake fluid went below minimum.

Now we have a brake failure warning on the dash and braking performance is not as good as normal.
Esc is disabled and auto parking brake is disabled.
Very odd.

Any advice? Tried a cheap code reader but code reader wont speak to the car so we cant clear the codes.

Any help appreciated!!


**just an update…..tried disconnecting the battery under the boot floor for 15mins….no difference, fault still exists.

[Carabind]

All may not be lost.

I had similar with a Ford Focus but managed to tighten the brake nipple before the reservoir ran too low

Do you have a firm pedal.
If yes, it may be that the pads and discs need a bit of bedding in before you’ll see full efficiency…maybe 10-20 miles. If this works, then if I were you, I’d try a friendly garage who will plug in their diagnostic reader and clear the codes for a few quid.

If no and the pedal is spongy then you have air and will need further bleeding. This may need VIDA or other suitable software


But if in any doubt, I’d get the car towed to a garage. Brakes are something where you don’t get a second chance.

[Kugaman1]

Thanks Carabind.
Brakes are firm, almost feel unassisted but pedal is firm….

Have driven a few miles to test on quiet roads…..brakes seem to work ok but are not as good as usual……Im not sure if its down to the new discs and pads or there is air somehow in the system.

Brake fluid never got too low in the reservoir and a gunsin bleeding kit with one way valve was used.
Just so odd when the abs pump seemed to kick in……car was turned off but key was in car…

Im going to a local garage tomorrow to see if they can reset the codes and we will take it from there….

[KungFooBob]

It may be that the ABS valve block/pump needs cycling. The dealer usually does this with the software when changing the fluid, however you might be successful in getting the ABS to kick in.

On a quiet/private lane try and get the brakes to lock, probably safer/easier if it's an gravel track. This should cycle the valves enough to release any trapped air/fluid.

Or it might not be anything to do with it, but it's free to do so worth a try before an expensive trip to the stealership.

[Kugaman1]

Thanks gents…

All sorted now….

Turns out, if you try to bleed the brakes using the old fashioned pump the pedal method, the car senses the sudden loss of brake fluid/ brake pedal issue and shuts down that leg, thinking theres a big leak and to preserve braking to the other 3 wheels. Really clever, but a pain for the home DIYer.

This then throws up lots of alarms.

Had to go to a local garage that uses a state of the art Bosch diagnostic machine.

Cleared the codes and all is well again!

[Philip Fisher]

Originally Posted by Kugaman1

Thanks gents…

All sorted now….

Turns out, if you try to bleed the brakes using the old fashioned pump the pedal method, the car senses the sudden loss of brake fluid/ brake pedal issue and shuts down that leg, thinking theres a big leak and to preserve braking to the other 3 wheels. Really clever, but a pain for the home DIYer.

This then throws up lots of alarms.

Had to go to a local garage that uses a state of the art Bosch diagnostic machine.

Cleared the codes and all is well again!

I have also heard that using that method can damage the master cylinder as you are driving the piston in further than usual and corrosion will have built up on the piston and wreck the seals.

How should a DIYer do it then? I have a pressure bleed kit and was going to change the fluid on the V60 some time this spring. I would do it without the ignition on and without pressing the brake pedal.

[Kugaman1]

I think a pressure bleeding kit is absolutely the only way to go.

No interaction with the ignition, pedals, servo etc…definitely my next purchase…..

Any recommendations for the best value pressure bleeder?

[TeamG]

I use a massive syringe and an old bit of tube from a previous bleed kit and leave the ignition off. Just suck through a whole load of fluid and keep topping up. I think my syringe does 600ml, but I tend to take about 200ml per pull.

[Kugaman1]

Originally Posted by TeamG

I use a massive syringe and an old bit of tube from a previous bleed kit and leave the ignition off. Just suck through a whole load of fluid and keep topping up. I think my syringe does 600ml, but I tend to take about 200ml per pull.

Are you pulling out at the nipple end? Isnt there a risk of introducing air into the line?