Back brakes wont bleed and pedal is spongy

[raul2000]

Hi guys, i have a mercedes c200 w204, 2009 and the rear break pipes broke in the same time, took it to my mates garage and we changed the pipes and pressure bled the system, now the pedal is spongy and only the front breaks work, we have bled the abs pump and master and we have got no air out of them
His diag tool doesn't allow us to use the bleed function, is there any other way to make them work?
Can anyone help?

 

[M80]

What pressure does his bleeder bleed at.
I had similar trouble till I bled through with a 2 bar bleeder.

 

[raul2000]

About 15 psi

 

[EmilysDad]

I remember once trying to use an Ezibleed without letting the pressure down on the wheel ..... there was brake fluid everywhere!!

 

[M80]

I remember once trying to use an Ezibleed without letting the pressure down on the wheel ..... there was brake fluid everywhere!!

I didn't really get on with the Eezibleed. On recommendation I picked up a Sealey VS820.

 

[raul2000]

Well i just did another bleed with 20 psi on the rear brakes and abs pump as well, after the abs pump the front breaks have very good liquid pressure and the rear just trickles down no matter if i press the pedal or it has pressure from the bleeder, also phoned my local merc garage and they said I've done it right and it should work
I have no idea what to do now

 

[Jason63]

The holes in the bleed screws could well be blocked which is preventing a decent flow. You'll need to take the nipples out and poke something through the small hole to clear it out.

You can try pumping the brakes whilst pressure bleeding. I'm pretty sure BMW say 10 pumps of the pedal if you have opened the system.

It does sound like there is air in the rear pipework or calipers.

 

[raul2000]

Thx but I've tried that too, i think ill just take it in to mercedes

 

[EmilysDad]

Thx but I've tried that too, i think ill just take it in to mercedes

you must be able to find a trusted local garage other than MB ....

 

[raul2000]

Welcome to wales m8

 

[EmilysDad]

Welcome to wales m8

it's not a 3rd world

 

[M80]

it's not a 3rd world

By population Ingland is 1st,
Jockland is 2nd.
I guess it's a good job N.I. isn't turd, like Charles the.

 

[green lantern]

Blocked flexi or you've left a clamp on one.?

 

[raul2000]

Blocked flexi or you've left a clamp on one.?

Is it more than 2 flexi pipes? The only ones I've seen are next to the master and those seem to be ok, no clamps left anywhere tho

 

[EmilysDad]

Is it more than 2 flexi pipes? The only ones I've seen are next to the master and those seem to be ok, no clamps left anywhere tho

there's a flexi to each wheel's caliper .... there has to be to allow the wheel to go move up & down

 

[raul2000]

Those are fine, i didn't think to write about those too

 

[w204benz]

I looked up the brake bleeding procedure a few months ago as I was having a bit of work done on them. Fairly certain WIS specifies the bleed pressure as 2 bar (29 psi).
Perhaps the last bleed was still at too low a pressure to get all of the air out of the system?

 

[raul2000]

I looked up the brake bleeding procedure a few months ago as I was having a bit of work done on them. Fairly certain WIS specifies the bleed pressure as 2 bar (29 psi).
Perhaps the last bleed was still at too low a pressure to get all of the air out of the system?

Wouldn't that break the reservoir? I'd do that too but im just a bit concerned I'll break it and spill break fluid everywhere

 

[spenttherent]

It could be a load sensor restricting the pressure, if your wheels are hanging in mid air

 

[M80]

Wouldn't that break the reservoir? I'd do that too but im just a bit concerned I'll break it and spill break fluid everywhere

Didn't on the 639 or the 211.
There wouldn't be much point in designing the 2 bar pressure pump if it broke cars.