What To Do If My Vent Lid Is Hitting The Vent Cover?

Updated 05/14/2025 | Published 04/26/2025

Products Featured in This Question

MaxxAir II RV and Trailer Roof Vent Cover w/ EZClip - White

(721)

$37.58

LaSalle Bristol XTRM Universal Self-Leveling Sealant - White - 10.1 oz - Qty 1

(388)

$24.16

Replacement MaxxFan Plus 4-Speed Roof Vent with White Lid

(95)

$225.81

MaxxAir FanMate RV and Trailer Roof Vent Cover - 26-1/2" x 18-1/8" x 10-1/4" - White

(517)

$72.21

Question:

I have max air model 4751ks power roof vents on my 5th wheel. If you open the vent all the way, or turn the fan on, it automatically opens all the way. I bought max air 2 vent covers, but with the lid all the way up the cover is 3” from roof. The included brackets in no way will line up to mount to lip on vent too high. Any ideas?

asked by: Shawn A

Expert Reply:

Hi Shawn!

You're dealing with a common issue when installing a MaxxAir II cover # MA76JR on a MaxxFan 4751KS, like the # MA00-04751KSX. Here’s the situation you're running into:

-First, the MaxxFan lid opens almost vertical when fully opened (especially when turned on), which lifts it very high off the roof — too high for the MaxxAir II to clear with standard mounting.

-Second, the brackets included with MaxxAir II are made for normal lower-profile vents, like typical crank vents, not these powered fans.

The quickest and easiest way to remedy this is to limit the vent lid travel. You can adjust the open limit so it doesn't rise so high. It will still move enough for good airflow, but it won't hit the cover. This is often done by moving or modifying the lid lift arm or adding stops. Depending on your comfort level, you can either put a small physical block (like a self-adhesive rubber bumper) on the lift track so it can't overextend.

The other option is to use longer spacers or custom brackets. Instead of the short MaxxAir II brackets, I have seen people use longer L-brackets from a hardware store. Mounting this kind of bracket to the vent's metal frame or to the roof around it (using something like the LaSalle Bristol XTRM # 34427034145-1 sealant) gives the MaxxAir II cover a "lift" so it clears the fully opened vent. You’ll likely need about 3-inch stand-off height based on your description.

The only other option would be to swap for a MaxxAir FanMate # MA00-955001 cover instead. The FanMate (different from the MaxxAir II) is specifically designed for MaxxFan-powered vents, so it is taller and shaped to allow full lid operation without any modifications. It even comes with a quick-release hinge, making cleaning and maintenance easier.

If you're comfortable tweaking things, limiting the lid travel slightly or use longer brackets would be the quickest and least expensive way to proceed.

If you want a cleaner solution without modifying your fan, definitely swap to MaxxAir FanMate cover as it is designed exactly for your situation.

expert reply by: Lazer S

Shawn A.

5/13/2025

Thank you for that info, that helps. I would definitely be interested in learning more about the limit stop adjustment. I’ve also noticed that when it closes, the motor pulls it down quite a bit to make sure it seals (I assume). That, I suspect is what has caused the stress cracks in the lids to begin with. That I will address as well.

Lazer S.

5/14/2025

@ShawnA So unfortunately, I don't really have anything pertaining to doing this as it will be a DIY thing, but it should be pretty easy and straight forward. : )