Brake job gone bad

[Imcallumwbu]

Hi, new member here.

I have a Vauxhall insignia 2010. I accidentally stripped the bleed valve during a break job so I’m going to replace the two rear callipers as a pair. The callipers are off and awaiting delivery of the new ones, but once reassembled, how do I fill the dry system of fluid?

I am competent bleeding the lines, but I’ve heard things like the ABS module and master cylinder will also need bled? Is this true?

All of the fluid leaked from the bleed screw overnight, and the master cylinder reservoir is dry. Do I just fill it up and keep purging it through the system by either the two man method or using a vacuum on the bleed valve and work around all 4 callipers? Or is there something more involved?

TIA

[GreenV8S]

There will probably be a specific procedure you need to follow to fill the ABS, and it may involve using diagnostic software to put the ABS controller into the right mode.

[Imcallumwbu]

Thanks for the quick response!

Do you know where is best to look for more information on that process?

[Boosted LS1]

My car has abs and when I fitted new front calipers I just used an Easybleed. Didn't encounter any problems.

[Chris32345]

Unless the whole system has been drained you should not have to worry about bleeding the abs or master cylinder


Edit missed the bottom bit

Fill the system like normal and leave it a bit of time to drain part way through then bleed your preferred way
E.g pedal pumping or pressure bleeder.

Abs will need a diagnostic system to activate the abs unit bleed function to open the drain and fill valves on the unit

Edited by Chris32345 on Monday 15th March 17:11

[Hammer67]

Whenever I fit new calipers I fill them with fluid first using a syringe.

[Imcallumwbu]

Thanks all.

I am going to try and fill the system as usual and put as much fluid through as I can. If the pedal is spongy I’m sure I’ll be able to find someone or a garage with a diagnostic tool who can run the ABS purge through the system for me

[Imcallumwbu]

Hi, just an update I suppose. So I replaced front discs, back discs, pads, and callipers, and also flushed through all four with fresh brake fluid. There is breaking, rear handbrake works perfectly, but the pedal is spongy and I’d say I’m down to about 40% braking power.

Any ideas of what I might have missed before I pay a garage to do a proper system flush, bleed and ABS module bleed?

[Hammer67]

An old school trick is to clamp all 4 brake hoses. Then test the pedal.

If it then feels better, the fault lies with one (or more) of the calipers / drums.

Unclamp one hose and retest, rinse and repeat to find which corner is causing the soft pedal.

If with all 4 clamped the pedal is still soft the issue lies upstream of the clamps.

Note, this is old school, something I was shown waaaaayyy before ABS etc so be careful.

[Matt_E_Mulsion]

It may just be as simple as everything needing to bed in, especially with new discs and pads all round. Personally I'd give it a couple of hundred miles and see if the feel comes back. Maybe also re-bleed the system at that point if it still doesn't seem right, before you hit the panic button and take it to a garage.

[E-bmw]

EXACTLY how did you bleed the system?