Hello,

Been a very long time since I posted on this forum but I am in need of help with a problem I been having. So about 2 years ago I noticed that my tail gate wasn’t going up/down so I did some research and found out that my pump was getting water to it and it was completely rusted. I ended up buying a used pump on eBay and installing it. At that time I had installed the tail lights from a 2010 gl450 as my car is 2008. The reason for installing 2010 tail lights was that newer ones had the led bulbs in it. Since I had gotten water in the area where the tail gate hydraulic pump was sitting I figured it was because I didn’t have the tail lights’s fasten nuts tight enough leaving space for water to get in. I decided to put back the 08 tail lights and all seemed ok until about a month ago when my tail gate stopped working again. Well once again I noticed that my tail gate hydraulic pump was completely rusted. I once again bought a new pump on eBay but I would rather not keep replacing the pump every two years if possible so I am seeing if anyone can direct me to where the water could be coming from? Is there an updated gasket for the tail lights? Also I have noticed that when I installed the new hydraulic pump and filled it with the correct hydraulic fluid that it doesn’t go up/down. I read that there are sensors on both sides of where the tail lights sit that are responsible for allowing the tail gate to go up/down. I ordered and replaced them as well but I am really concerned with finding this water leak.

 

There are many threads on this forum regarding 'water intrusion'. DO a quick search for your reading pleasure.

Of the many culprits, leaking roof rails seem to be the prevailing one. They leak at the attachement points due to worn gaskets. If you have any play/wobble in the roof rails, you likely have a water entry point.

For the interim, pop one of the rubber grommets on the floor of your spare tire well to allow any potential water accumulation to drip out. That should extend the life fo your pump. Also, if parking on an incline, face downhill so that any water does not drain toward the tailgate.

On that note, check under your front seats for water accumulation (battery compartement as well as under driver's seat).

 

Ditto what Miguk Saram said.

You also might want to consider eliminating the power tailgate (pump etc) entirely.

 

Install the new pump then wrap it up in a thick plastic bag until you get the leak issue fixed.

 

Anyone have the part # to the grommets for the roof rack

 

It's more like a gasket.

The problem is not the gaskets, but the nuts holding the roof rack down from the inside. The headliner has to be removed, or at least holes opened in it, to access the nuts.

If you get to the point of replacing the gaskets, I'll get you the part numbers from EPC in exchange for pictures of your suffering.

 

 

Ok, so the I got the tailgate to go up with the hydraulic pump but when I press the button it doesn’t want to go down. No matter if I hit the remote button or button on the tail gate itself

 

We're gonna need more than that.

First, does the motor make any noise when you press the button? Does the tailgate 'attempt' to close? Can you close it manually? Does it require a lot of effort to pull/push it down? Have you checked the reservoir fluid level?

There are a number of threads on tailgate malfunctions. Do a quick search and, preferably, post follow up questions on those threads (just to keep things organized for posterity).

 

Ok so I will answer your questions one by one.



First, does the motor make any noise when you press the button.

The buttons either on the tailgate or key remote doesn’t cause the motor to make any noise.

Does the tailgate 'attempt' to close?

Nothing happens at all

Can you close it manually?

Yes

Does it require a lot of effort to pull/push it down?

So with the key remote or tailgate handle the tailgate goes all the way up with out an issue. The problem is that with the tailgate button or key remote button the tailgate won’t go down at all nor makes any motor noises. So it requires decent amount of effort to close the tailgate.

Have you checked the reservoir fluid level?

Yes, completely fine as this is my second pump installed over the last 3 years. Due to a leak that I thought I fixed before but I guess I didn’t.

Lastly I have checked the forums and couldn’t really find any posts with my specific problem.

Also I have scanned my gl with the star Mercedes computer and get no codes.

Question has Mercedes updated the gaskets for the tail lights for the left/right sides? If so anyone have the part numbers?

Thank you for responding.

 

fixed!!!!! So here is how I fixed my issues. I replaced both tailgate sensors. Parts numbers 1648706610 & 164706510. These sensors were ordered from a Mercedes dealer in Miami for $35 each. After installing these sensors I topped off the hydraulic pump for the tailgate and presto all working fine!!! I am just hitting 94k miles on this 2008 Gl450!!!

 

Thanks for posting your results. Its nice when someone comes back with a solution

 

Having the exact same problems. Got the pump hydraulic fluid refill did not work. I believe i have similar issues. Goes up but does not come down. Will order the parts. Although I couldn’t find at your price point. Please DM on what dealership your ordered from