Mrooyen

Hi All.

All the trunk functions work with one catch. I have to assist the opening very slightly at the start. After I push it for about 1 - 2 cm its all good from there.

It closes fine just needs a little prod when opening. Is this the motor that needs attention? Or any suggestions please. It is 8 years old.

Regards

biker349

probably need to refill the hydraulic fluid in the pump.

Mrooyen

Ahh right. Is this easy to do? Do you have some more details on how to achieve this and what fluids to use?

Cheers

Dr Matt

Could also be weak trunk struts. Mine was the same way, I replaced the struts & it works fine now.

The pump is located under the battery in the trunk so remove the battery and you will find it. I checked mine before replacing the struts. It was full so I didn't add fluid.

awiner

Its your hydraulic ram (probably needs hydraulic fluid as mentioned above).

Search my posts. You will find all the info you need to accomplish this fix.

The Struts on the electronic optioned trunk only assist in keeping the trunk open. they have nothing to do with the opening process.

radride

I did the same thing.

R.K.

Mrooyen

Hi thank you for the info I found your previous post and will have a look tonight? just a couple of quick questions:

What fluid should I use the owners manual does not list the trunk only
Hydraulic system for ABC approx. 4.2 US qt (4.0 l) MB Hydraulic fluid.

Also

Do I need to disconnect the battery? If yes will it reset any setting etc.

Cheers

Dr Matt

Yes you will have to disconnect the battery because it must be removed to access the pump. Yes you will have to reset your clock, radio stations, sunroof, and windows. Info on how to all of this is in your owners & command manuals.

awiner

Regarding the fluid, standard 'red' hydraulic fluid is what the factory uses. You can also use ABC fluid with no problem but it is more expensive due to the specs.

Mrooyen

thank you. I was hoping that the fluid would solve my issue as well. I checked it and it had fluid still in. I replaced it with new fluids while I had everything out anyway. But Like the DR. Matt mine still does the same. So strut change as well then. Is there a trick to getting them off? I read somewhere it takes 5 min to replace.

Cheers

awiner

The struts are held on by a clip that simply pops on and off with a small flat blade screw driver.

Mrooyen

OK nice that sounds simple enough

I ordered them from MB here in UK at £35 a pop same part number as listed for the CL55.

Thank you very much.

kk100

Hi, I have the exact same problem. Can you post the part numbers
Cheers

awiner

A215-750-03-36 (Left)

A215-750-04-36 (Right)

kk100

Thanks!

Mrooyen

Hi

Wanted to say thank you for the info and advice. After replacing the struts that really took only about 2 min and most of that is getting it out of the packaging :P the trunk opened fine. It did not want to close at first so I had to nudge it a bit down. Opening and closing the trunk a few times seems to have done the trick and it all works fine now.

Cheers