Jackarelli

Hi All,
I'm hoping that somebody may be able to help me with a puzzerling situation.
I have an e60 530d 2004 which was suffering from an extremely spongy brake pedal.
On closer inspection I have discovered that the front brakes are not engaging only the rear ones.
I have bled the brakes and that didn't help I have checked the master cylinder pressure and that seems fine.
Is it likely that it's the ABS pump as I've not heard it causing this particular issue before.
Or am I missing something that I haven't checked
Any input would be greatly appreciated
Jack

twh

Are both front brakes not engaging? I suppose you could have a stuck caliper. Usually they get stuck in the applying brake position.

Jackarelli

Hi,
Yeah unfortunately there is no pressure getting to either of the calipers on the front of the car.

DanL

What process did you use to check the master cylinder pressure?

Jackarelli

I locked off all the brakes and pedal was rock hard
I also cracked off the nuts to the abs pump from the master one by one and they all pump out fluid nicely however the front nuts seems to extrude a fluid that contains more air isn't as clean.
I wonder if something inside the abs is pump is broke.
I have not seen or heard of this before so not really sure.

Jackarelli

Sorry to bump this but is there anymore input on this before I just stump up and order a new ABS pump?
Looks like I'm going to have to start replacing parts bit by bit
Thanks
Jack

txag_530i

There's clearly a leak somewhere. I'd check all of the hoses and tubes for leaks before throwing parts at the problem.

evolotion

pads stuck in the carrier, when you press the brake the pads bend a little, then spring back pushing the pistons back, Dismantle, clean, lubricate(where appropriate), and re-assemble. wont cost a penny to do and helps rule out that as a problem. also gives you a chance to check the sliders and pistons .

Jackarelli

Hi guys,
Thank you all for you input I just wanted to update this with the resolution.
After stumping for a new abs pump I was quite disappointed that it didn't remove the issue.
It was however resolved with a new master cylinder.
Never had one which went on front only but ow well live a learn
Thanks
Jack

twh

Thanks for the update. Good information. I could swear that the two circuits in the master cylinder went to diagonal wheels. That is, each master cylinder fluid circuit went to one front and one rear brake. Maybe that's the way it was in the old old days I've had bad master cylinder before, but as I recall, the pedal really let's you know something is very wrong.