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Discussion Starter · #1 ·
Hi y'all,

I have installed a Retrax Tonneau cover (well, almost) on my 2019 3500HD. I still need to make holes for the drain hoses. I guess I didn't realize it drains from the bottom of the roll-up box rather than from the top of the rails (duh) so I can't use the factory punch outs as they are way too high.

I need to make holes big enough for the two tubes, which are about 7/8" in diameter each. Going through the bed wall against the cab seems to be the most logical place.

Any advice on drill bits? getting through the spray on-liner cleanly? protecting the newly bare metal? grommets to keep the hose in place? etc?

Thanks for any thoughts.
 

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i would use a step bit, paint the exposed metal, and install a grommet like this if you would like to prevent wear on the hose. The bed liner is just rubber, the drill bit will go right through it.




 

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Local shop installed mine. They ran the hoses out the bottom of the bed. Painted the bare metal from drilling the holes.
 

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Local shop installed mine. They ran the hoses out the bottom of the bed. Painted the bare metal from drilling the holes.
That's how my Roll-N-Lock drains. And if the box gets leaves in it and the drains block, the overflow will drain out the same holes, around the clear tube.
I'm always unblocking those drains.
 

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Discussion Starter · #6 ·
Thanks for the replies.
 

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I installed the ReTrax on my 2018. Your going to love that cover. It is the best one out there for security and being weatherproof.
 

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Local shop installed mine. They ran the hoses out the bottom of the bed. Painted the bare metal from drilling the holes.
Seems like they could have put those closer to the bed wall... 'uhNo

To the OP, i'd tuck them as far fwd and to the sides as possible keep clear of loads in the bed.. my 2cnts
 

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On my 2020, I installed a Retrax. Had the same issue - the plugs on the bed sides were too high.

I used the factory-drilled holes in the very front of bed that allow the bed to drain. But, the Retrax came with 1/2" hose - I bought some 1/2" - 3/8" barbed brass reducers from Lowes, and some 3/8" ID tubing. The smaller tubing fit without any issue through the factory holes, and it's actually snug enough that it grips the tubing and keeps it in place.

Initially I was going to drill as you're considering, but I'm glad I didn't.
 

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On my 2020, I installed a Retrax. Had the same issue - the plugs on the bed sides were too high.

I used the factory-drilled holes in the very front of bed that allow the bed to drain. But, the Retrax came with 1/2" hose - I bought some 1/2" - 3/8" barbed brass reducers from Lowes, and some 3/8" ID tubing. The smaller tubing fit without any issue through the factory holes, and it's actually snug enough that it grips the tubing and keeps it in place.

Initially I was going to drill as you're considering, but I'm glad I didn't.
Will the 3/8 tube od fit the 1/2" id hose tight enough that no fittings/reducers are required?

I was going to try it, but haven't yet got it done :frown2:
 

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Will the 3/8 tube od fit the 1/2" id hose tight enough that no fittings/reducers are required?

I was going to try it, but haven't yet got it done :frown2:
I think it would fit, but I don't think it would be tight enough to completely seal the connection and you'd end up with water in the bed.

Here are some pictures of the connections. I trimmed the 1/2" hose shorter so that the brass reducer was higher up in line and the majority of the hose was the 3/8" size.





 

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Retractable design seems a PITA
I've had two retractable tonneau covers and I doubt I will have another. There are a pain, pricey, and not very weather tight. I really thought the 1st one(Retrax) was just a poor design, but the 2nd one(Rollbak) was worse than the 1st one.
 

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Bare metal

Hi y'all,

I have installed a Retrax Tonneau cover (well, almost) on my 2019 3500HD. I still need to make holes for the drain hoses. I guess I didn't realize it drains from the bottom of the roll-up box rather than from the top of the rails (duh) so I can't use the factory punch outs as they are way too high.

I need to make holes big enough for the two tubes, which are about 7/8" in diameter each. Going through the bed wall against the cab seems to be the most logical place.

Any advice on drill bits? getting through the spray on-liner cleanly? protecting the newly bare metal? grommets to keep the hose in place? etc?

Thanks for any thoughts.
After drilling coat bare metal with liquid tape it is black and works great
 

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So gpadoug...what type/brand tonneau do you like/recommend?
I still have the Roolbak retractable on my 3500, but will probably go with a solid top tri fold on my next 3500. I haven't done any research on particular brands as of yet, but know that a hard top tri fold would better suit my needs than a retractable tonneau. All styles have their strengths/weaknesses so it's a matter of determining which best suits your needs. Some of the weaknesses are only discovered after you have owned it. That's why it's helpful to read what owners have to say about theirs, both postives and negatives.
 

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After a year and eight months I have found nothing negative with my Retrax. I have friends that bought there's after they seen mine and I have not heard one complaint.
 

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Local shop installed mine. They ran the hoses out the bottom of the bed. Painted the bare metal from drilling the holes.
That is how they did it for the previous owner of my truck. I just removed the powered retrax after it had been in the truck for 11 years and a few years prior to that in his 03 Duramax. The thing finally wore out.
 

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I have the Pace Edwards and installed the drains in the floor, don't like them there so I'm going to drill new holes in the back wall between the bed and cab. I plan to install an Aux fuel tank and having the tubes in the floor will be in the way.
 

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