E420 ASR Accumulator / booster

[Sasha124]

Hi guys! 1995 w124 e420 vin WDBEA34EXSC263431 looking for Brake Accumulator what located behind driver side front fender. My question does that will fit 0004300594 ? Loolike it from r129. If not please help with correct part number. Thank you 90-97 Mercedes R129 SL500 600SL Brake Booster Accumulator Unit 0004300594 OEM | eBay

 

[gsxr]

EPC shows p/n 000-430-10-94 would be correct for the W124 with ASR.

000-430-05-94 should also work, it was replaced by 000-430-10-94 on the 129. Check the part number on your existing one too.

 

[Sasha124]

EPC shows p/n 000-430-10-94 would be correct for the W124 with ASR.

000-430-05-94 should also work, it was replaced by 000-430-10-94 on the 129. Check the part number on your existing one too.

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OMG you as always The Best!!! God Bless you! Really! Thank you for your patience and big help! I will able to see mine tomorrow because its in mechanic shop. I think 99% i will go with that from 129, because price is good..

 

[northNH]

Dis?
Available…

 

[Sasha124]

Dis?
Available…
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Probably yes, but I didn’t see my car personally, but it should be that. I just ordered that one from R129. I hope it will fit..if no i will contact you. Thank you

 

[gsxr]

Note that the ASR pressure accumulator is barely visible in the above photo... it's the small round can, not the large rectangular one.

 

[Sasha124]

Note that the ASR pressure accumulator is barely visible in the above photo... it's the small round can, not the large rectangular one.

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Thank you! I took it from same car i have E420. When i brake a part metal tubes some pressure gas went from them. I hope that pump don’t need to be gas recharge or something, there is no power wires, how does it work?

 

[gsxr]

It has a gas-filled chamber similar to the rear SLS spheres. Pressure is from the ASR/ABS unit. It's sort of a holding tank for fluid & pressure, hence the name "accumulator"... might be more details in the FSM descriptions of the ASR system.

 

[megdan]

Sorry for bring back this old thread, but I am in process of restoring e 400e and really have to remove the Pressure Accumulator for the ASR. Are there any precaution that I should take ? I plan to first flush the brake fluid from the ASR bleed valve then remove the 2 lines to the accumulator. Is that all ?

 

[gsxr]

Sorry for bring back this old thread, but I am in process of restoring e 400e and really have to remove the Pressure Accumulator for the ASR. Are there any precaution that I should take ? I plan to first flush the brake fluid from the ASR bleed valve then remove the 2 lines to the accumulator. Is that all ?

The FSM procedure only says to depressurize the "SP" port on the ASR unit:

https://www.500eboard.co/forums/misc/Manuals/Servicev3.2/W124/w124CD2/Program/Chassis/42-0819.pdf

 

[emerydc8]

At least two of us have had issues with the SP port bleeder valve being seized in the ASR unit resulting in it being rounded off by the wrench. Then when escalating with vice grips the bleeder valve breaks off inside the unit. I don’t know if pre-spraying with Liquid Wrench would prevent this (perhaps @Jlaa could chime in). Maybe one of those induction heat ring tools would help prevent this, as the @gsxr suggested. Just be aware that if the bleeder valve hasn’t been opened for a long time you could run into this issue.

Thread 'Anyone have specs on the ABS Pump Bleeder Screw 000-420-49-55?'
Anyone have specs on the ABS Pump Bleeder Screw 000-420-49-55? | Brakes, Suspension and Steering

 

[gsxr]

All of the above is incentive to make sure to flush/replace brake fluid every 2 years on schedule, keeps that SP bleed screw freed up!

 

[emerydc8]

I just ordered two from Amazon in case they go NLA like the factory valve.

 

[Kridre]

I will only add that you absolutely need to make sure that you connect the brake lines going in to the accumulator and abs pump correctly. Otherwise you can damage your abs pump or accumulator.

 

[TerryA]

Maybe this is a dumb question, but if you bleed all 4 brakes won’t the new brake fluid eventually get replaced in the ABS pump.

Maybe bleed the brakes twice in say a month.

Leave the ABS screw alone. It’s obviously a victim galvanic corrosion. 2 different metals steel & aluminum.

 

[emerydc8]

Maybe this is a dumb question, but if you bleed all 4 brakes won’t the new brake fluid eventually get replaced in the ABS pump.

Maybe I’ll try this as an alternative to drilling.

 

[gsxr]

Maybe I’ll try this as an alternative to drilling.

The ASR pump has a reservoir inside that may never get flushed out, unless port SP is opened. Still, this should be a minimal amount of 'old' fluid in the system. Replacing the bleed screw would be best, if possible. Worst case you'd have to replace the ASR unit (there should be plenty of good used units available - there's no demand because they rarely fail).

 

[gerryvz]

The ASR pumps are fairly readily available. I've passed over dozens in the wrecking yards over the years in various 124 and 140 models. It's a commonly used part from the 1990s.