Hi all - brake advice CLK230

[peteb]

Hello,

Recently purchased this car but have a problem with the brakes so far changed all the pads and bled the system but still have the same problem - which is pedal travels almost to floor very spongy the brakes work but poorly however without the car started the brake pedal is hard only when the car starts does it travel. have checked for leaks - none?

Any ideas appreciated

Regards
Peter

 

[peteb]

oooooops

Please can this be moved as posted in wrong section?

Also it is a 1998 CLK230

Thanks

 

[roofless]

sounds like you still have air in the system as for the hard pedal when not started its due to no vacum thats normal it will be soft for one press then hard its poss you have bled them in the wrong order & as i have never done a clk i cant help with the order but it will poss help get you on the right track

 

[peteb]

sounds like you still have air in the system as for the hard pedal when not started its due to no vacum thats normal it will be soft for one press then hard its poss you have bled them in the wrong order & as i have never done a clk i cant help with the order but it will poss help get you on the right track

Thanks roofless

Anyone who does know order was LR-RR-LF-RF hope this is correct?

 

[David Nock]

Standard order for cars in general was always furthest away wheel to nearest wheel (to master cylinder).
I would think your order is fine.
I would bleed again to make sure that every bleed nipple is free of air bubbles. Also nip the bleed nipples up whilst your assistant is still on the final downstoke of the brake peddle, not when the peddle is floored.
Good Luck.

 

[peteb]

Thanks but bled 3 times now still the same - looking elsewhere now?

 

[David Nock]

A seal might have 'rolled' in the master cylinder whilst bleeding? Never happened to me but I'm told it can happen as the seal travels much further than normal onto possible wear lips in the master cylinder bore.
Also is every caliper piston moving? Has one stuck back whilst pad changing, hence resulting in disc rotor flexing as only braking on one side of the rotor? This could be checked by inspection?
Finally are all the hoses sound? a hose connection to a caliper has not 'given out' ie frayed inside has it?

 

[peteb]

A seal might have 'rolled' in the master cylinder whilst bleeding? Never happened to me but I'm told it can happen as the seal travels much further than normal onto possible wear lips in the master cylinder bore.
Also is every caliper piston moving? Has one stuck back whilst pad changing, hence resulting in disc rotor flexing as only braking on one side of the rotor? This could be checked by inspection?
Finally are all the hoses sound? a hose connection to a caliper has not 'given out' ie frayed inside has it?

Would a sticking pistion cause this problem?

 

[David Nock]

Maybe, but perhaps I should have thought it out a bit more. On some cars there are dual piston calipers on the rears and/or single 'clamp over' type calipers on the front.
Either a sticky piston or more likely a sticking caliper frame would result in braking to one side of the rotor only, therefore causing flexing and spongyness.

 

[Mr Teddy Bear]

Try having her pressure bled before stripping the master cyclinder.

 

[Blobcat]

Please can this be moved as posted in wrong section?

Also it is a 1998 CLK230

Thanks

Moved