Sbc pump

[Dieselman]

Sent in my 7 year-old car today due to sbc pump problem. Was told that there's no warranty 'cos mulfunction was due to "pressure ball" within the pump rather than the pump itself. However, need to change the whole sbc pump 'cos "ball" not sold separately!!

Does it make sence?

Yes it does and the accumulator is probably classed as a wearing part, though it's then surprising that it's not sold separately.

Maybe it could be recharged if not ruptured.

 

[Dryce]

Rubbish, checked with my dealer a couple of months ago and it is free replacement for ten years as long as it has a full MB service history, so you should be fine. Probably got an advisor who's never come across the problem and got the standard line for any other major problems.

Or maybe your advisor hasn't had to get one authorised recently .....

Or another unwritten policy change .....

Posts here and elsewhere over the last 12 months have reported MB wanting 50% (or conversely offering 50% contribution) of the costs to replace the pump with FMBSH.

 

[mersum1es]

Yes it does and the accumulator is probably classed as a wearing part, though it's then surprising that it's not sold separately.

Maybe it could be recharged if not ruptured.

Benzworld.org - Mercedes-Benz Discussion Forum - View Single Post - Pressure Reservoir/Accumulator DIY ???

 

[Dieselman]

Accumulator not covered by MB.

Having brake problems and dealer says it's not the SBC. - MBWorld.org Forums

If it isn't ruptured it can be regassed.

One I made earlier on a different manufacturer car.

 

[markevo]

Took e class in for a service this morning--2.5 hrs. Recieved phone call computor has locked brakes as SBC pump has reached end of servicable life??? Price £130011 but not to worry its covered by Mercedes warranty for life of vechile
Any one else had this or am i being fobbed off, also if i had taken this to a indy for service would there computor have locked the brakes on and replaced free of charge??

I FEEL YOUR PAIN .......I had the same problem with MB when my E55 SBC unit came to the end of its working life . Called MB HQ in Netherlands only to get same response NO WARRANTY due to car being 2003 .
I eventually went to Dronfields in Oldham and purchased a second hand SBC unit that had be removed from 40k E500 for £240 then got my local indie to fit for £120 .......result !! All works as it should now and at the fraction of the cost .

 

[kennethcole79]

Dieselman

not sure if the accumulator can be regassed cause theres no refill valve on the top to recharge. not sure if you can recharge from the bottom. i do know that pressure from the accumulator should hold 150bar= to 2175psi.
is the accumulator gassed with nitrogen?

 

[Dieselman]

You need to drill the original plug in the top of the spheres, add a valve, then regas.

I can't see the original pressure being 150-Bar, that is system pressure, even so, that's no problem. The original gas is nitrogen.

 

[kennethcole79]

thanks for the info. yes your right 150 bars is the system pressure tested on the sbc system on star. have no idea what the actual regas pressure needs to be. you have any idea?

 

[Dieselman]

I would think 60 Bar would be a good reserve.

The one you see in the picture was being gassed to about 70 Bar iirc.

The brakes on a Citroen BX apply about 20 Tonnes of force to the brake pads. Seems to work.

 

[Stocho]

Good point had not thought about that - I guess it is the POTENTIAL for some really awful press if one of these SBC pumps failed and someone died in an accident. It would really scupper the MB brand for decades.
An engine wiring loom does not have the same consequences.

W210 suffers from catastrophic suspension springs perch failures. So there is a potential for the front suspension spring to suddenly fly from the car. Immediately the front would collapse on the wheel in question and the spring could also jam steering, or destroy tyres including rear one if driven over.

At high speed real risk of car becoming totally uncontrollable - yet no recall on that.

I suppose if a few Mercedes ownership drove their card to delership and exposed all the problems this would attract attention to the issue before someone actually dies... And quite possible people have already dies because of these faults - it is just not known.

 

[Dieselman]

You are overdramatising the issue. No spring perches break off completely and even then steering wouldn't be lost. All failures happen at slow speed as that is when the greatest load is applied.

 

[Stocho]

You are overdramatising the issue. No spring perches break off completely and even then steering wouldn't be lost. All failures happen at slow speed as that is when the greatest load is applied.

Why would greatest load be applied at slow speeds?

I believe the greatest load on the front driver's spring is achieved when braking from high speed on right bending road. Breaking shifts more load to the front and bend (which at high speed can be just a small curvature to the right) shift weight to the right.

In such a situation loss of the spring would lead to the body of the car pressing with great force on the wheel. This would happen in a situation already on the limit of controlling ability and would be likely to lead to a catastrophic loss of control.