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Discussion Starter · #1 ·
WARNING! - WARNING! Curt instruction manual omission may result in vehicle damage, costly repair and loss of warranty! MUST READ:

Removal of the factory bumper also removes a necessary weather seal that MUST be replaced to avoid water intrusion. Rain water may enter the chassis cavity leading water to the inside of the vehicle (yes, the inside of this "tube" is part of the INSIDE of the vehicle!) and end up on the floor of your car - as it did with mine.

I received a bill for $3,400 because MB treated as a factory defect and searched for the root cause by dismantling the entire interior of the car. I got billed for the hours of shop labor to repair it.

You MUST seal this opening from water intrusion. This is NOT explained or covered in any way in the installation manual. There are also 2 rubber seals that you can use for access to fill it up with a compatible expanding sealer. I cannot not emphasize more that this should be sealed. CURT made a huge omission and installation as per instructions can lead to car damage and warranty loss, thus costing you thousands of dollars to repair it.

Once installed, you should periodically check for water intrusion to confirm that your installation was water proof, especially after heavy rain or off roading. You can also check for water intrusion from the hatch by lifting the carpet and getting visual access to the metal as this channel does have openings to the interior of the car - hence considered as part of the inside of the vehicle. Use an inspection tool or dry paper towel to get it to the bottom of the channel and check for humidity. Also, the parafine anti rust agent must appear of yellow color (water pales it a bit). Regularly check your rear carpets for any sign of humidity until you are certain that the installation was waterproof..

IF you have witnessed windshield fogging while your vehicle has been parked under heat and rain, there is a high probability of water intrusion through the hitch receiver. Unfortunately that's how we found out. We did not noticed at first because the car sits in a garage and for the most part water evaporated before becoming a huge problem. When we had the car serviced for windshield fogging, the car sat in an open lot exposed to a month of heavy rain, accumulating enough to spill in the interior and evidently showing water intrusion on the rear carpets.

CURT made a huge omission that may result in vehicle damage and an expensive loss of warranty. You have been advised. Let's hope they correct the manual and communicate it to all customers. :(
 

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Oh man, so sorry. What a bummer. Thank you for sharing your experience and hopefully saving someone else the pain! Personally after talking to the dealership guys I decided to not pursue a trailer hitch on mine. Wife's car has one and I got roof racks, can live without it.

If someone is looking for one there is a great thread here or maybe another forum of a proper installation, be sure to find and check out if you're considering a hitch on your GLA.

Sent from my SM-G930V using Tapatalk
 

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Discussion Starter · #6 ·
If any of you owners have witnessed water in the rear passenger's foot well and do not have an installed hitch receiver, please contact me ASAP. A hitch receiver may favor this condition but if water ingreses the vehicle without one, it many point to a factory defect from a poorly design/installed seal at the rear bumper. I did find a user from this forum with the same issue but do not know if the owner has an isntalled hitch receiver because it is not mentioned in the his thread.
 

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As a Junior member the system does not allow me to post pictures or links...:(
If you can access it, I created an album called "Water Damage".
I took a look at the album but the pics were pretty blurred so I cant tell much about the details. At least I am forwarned and will be on the watch for this when I do the install.

It sure would be nice if this site was not so restrictive in giving basic privileges to new members, then you could pm me some pics...!
 

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Can you provide a paragraph or so about best way to seal up the opening after removing the bumper and before installing the hitch ?
 

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Discussion Starter · #10 · (Edited)
Can you provide a paragraph or so about best way to seal up the opening after removing the bumper and before installing the hitch ?
The bumper is held by four bolts on each side though a solid plate. That plate has a double-face tape between the plate and the chassis. That tape covers the opening. One solution to keep the car is came from the factory id to get an automotive square double face tape of the same size of the original and duplicate its location on the receiver's plate, thus duplicating the original tape.

Once you do that, and if you are as paranoid as I would be, the structural element hast 2 rubber covers: one on the side and one on the bottom. The one on the side is the easiest to remove from the out side. Remove it and fill the entire cavity with weat Her sealing expanding foam. You can actually confirm that you absolutely removed any poissibility of water intrusion by lifting the cargo carpet - the section has 3-4 openings that will let the sealant through, confirming that will be better sealed than the factory tape... in case you run in such situation. DO TAKE pictures for your records on all the measure you take to maintain vehicle integrity, as I will now do with ANY modification. Obviously do the same for both sides. Make sure you use one solid full-side tape just like the original. If you can't find one (thinking Amazon), make sure you use another type of automotive seal around the opening to serve the same function (i would suggest to duplicate the original). Do not forget to replace the rubber caps (if you remove them to fill the cavity) before the sealant sets. Filling the cavity with sealant may also be possible through the cargo area - this might be easier. I haven't done this as I do not have the car yet.
 

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So where did you post the Water Damage album that you mentioned?
I've got the Curt hitch on my 45 and all is dry, maybe it's an issue with the installer, I guess I got a good one, in fact they've been doing hitches for 40 years, took 2 guys a good part of the day and it turned out great. Especially since it's been 6 months and no water leaks (with lots of real hard rains and road water). Not doubting what you've gone through but the only way water could get in would be if they removed the gasket and then just bolted the pieces back together. I'm with you that a shot of sealant in there would have been a good idea for MB and then even in a wreck repair situation there'd be no leak.
As to the $3400, if the shop charges $150 an hour which I doubt (not sure where you are but $150 is pretty rich), that means they spent 22 man hours taking the car apart and putting it back together, my installer had 2 guys and spent about 4 hours, so that's 8 man hours as compared to what your dealer said he took and the dealer should be a pro at it. Hummmmmmm
 

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Sad story to hear.

I too have a curt hitch and bought it because it is built better than the other brands available.
I am worried about this as I am sure others who have installed hitches.
I researched very well and all the available hitches do not mention installing a gasket or sealing this area in their instructions (curt, westifalia, hidden hitch).

I have to ask, where are you located that cause this water intrusion problem? Do you live in an area with large amounts of humidity or snow?

The bumper cover and bodywork and rear hatch are all very well designed to route rainwater and other water away from this area so direct intrusion should not be possible.

Having installed my hitch myself, I did take photos and I know of the foam gasket you speak of. However that foam gasket is not going to stop direct rain water from intruding into that area, as the adhesive, foam thickness, and foam type, and how sloppily the gasket was applied to the bumper mounting flange are all just not going to cut it for direct rainwater intrusion.

I am not calling you a liar, I am simply very curious as to how the water did get in there. I wonder if where you live might have affected this, or is there a chance one of your sunroof drains or front firewall drains were plugged with leaves or ice allowing water to build up in other places.

Maybe the dealer was looking for an excuse to charge the labour and they saw the hitch and blamed the hitch as the area to allow water intrusion.

Vw's and Audi's in the past have had problems with water build up if the firewall pan did not have its drains cleared of small leaves/buildup etc, as this would plug and allow water intrusion via the A/C climate control air intake.
 

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Sorry to hear about the damage. I installed my Curt about 6 months ago and believe it has rained here in SOCAL and so far mine has worked like a charm. I'll keep an eye on it tho.
 

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It's now been over a year and mine is still perfectly dry and we've had tons of rain. I agree with several other posters, don't blame Curt and something is strange with the dealer or his story.
 

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2017 GLA250 4Matic, Cavansite Blue Metallic
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Coming late to this party, but wanted to note that I am getting ready to install a Reese Hitch on my wife's 2017 GLA250. The instructions are very clear to run a solid bead of silicone seal around that opening on each side. I snipped part of them, see item 6 and figure 4 below. Since the Reese hitch design itself blocks water from getting through the bumper beam, there shouldn't be any need to fill the beam with expanding foam.

Best of luck to everyone and have a safe, healthy and happy 2022!


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