SBC...

[LostKiwi]

It's finally happened.
The r230 SBC warning came up in red but funny thing is it goes off and comes on semi randomly.
If I brake hard I can reproduce the issue but with a second or two it goes away again.

With the bonnet open I can hear the pump cycling around every 5-10 seconds. It's like it has an internal pressure leak and is unable to maintain pressure.

I realise it's likely a fubared pump but just curious - could it be the accumulator on the pump has failed?

Any SBC gurus here?

 

[fabes]

Yes, yes there are.....

Sorry, not helping much, but I've had a few drinks and am in a funny mood
Again, apologies

 

[mersum1es]

Im not guru either but, yes, if accumulator has no gas compressibilty, total pressurized volume change will be so small that pressure will drop very fast. Fact that message disappears tells that pressure is reched eventually. Of course it not fully exclude pump/valve block failure. Accumulator failure has fault code of its own, and changing accumulator is pretty easy.

 

[LostKiwi]

Ordered some brushes for the motor anyway (it has 120k miles so they're probably getting close to their end) so will do that and see if it resolves anything then go for the accumulator.

 

[ajlsl600]

Ordered some brushes for the motor anyway (it has 120k miles so they're probably getting close to their end) so will do that and see if it resolves anything then go for the accumulator.

If accumulators will you not be topping oil?

 

[alexanderfoti]

It should not cycle that much.

Accumulator failure is possible, but an internal leaking valve will likely cause the same issue. I think you can buy the accumulators seperately

 

[PaulG]

I’m at 82k on my E240 and hoping that I have plenty of miles to go before the SBC pump needs replacing

 

[sonic]

I had the SBC warning light come up on my old 2001 CLK200K years ago, speedo was on 120K miles.

 

[Blobcat]

I had the SBC warning light come up on my old 2001 CLK200K years ago, speedo was on 120K miles.

I wasn’t aware they fitted SBC to CLK’s

 

[sonic]

I wasn’t aware they fitted SBC to CLK’s

I might be wrong but I got the red brake warning light on the dash on my W208, I assumed that was the SBC failing.
I part exchanged it very shortly after, so didn't get it sorted.

 

[ajlsl600]

I had w208 no sbc, (thank god!) one of the great things w208 is it has "enough tech, but not to much. That was the bait into benz for me, near 20 Yr, trouble free motoring, nothing like it since and all electric, electronic.

 

[Botus]

the way I understand it the sphere is the equiv of the vacuum assistance most cars get

its like all the early Boeing, Shitroen and RR's brakes- take a sphere and cut in half, now stretch a balloon across it. Rejoin the two halves. Next pump nitrogen in one side to a few hundred bar - the balloon is now squashed to the metal.... on the other side now fill the whole sphere pumping it full with brake fluid - you now have three brake presses of a very big rugby player waiting to help stand on the brakes when you want to slow down

however the balloon wears out and the rugby player disappears - leaving only a noisey pump trying to help a bit - thus the pump wear's out, as all it was supposed to do was a 3 second catch up now and then, not run every single brake press