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Rust Proofing for Canada

16718 Views 36 Replies 23 Participants Last post by  chrisbroncos76
What do you think about Krown rust proofing and drilling access holes? I looked at my KL and could not find any high point (not drainage holes) on doors and rear hatch. The hood is the exception but the sound proofing panel must be detached.

IMO, drilling holes will break the paint surface and invite rust. Please don't tell me to consult with Krown because they will assure me it is fine, I would like to hear from those who has actual experiences.

This question/discussion based on my own experience with a Mazda MPV, the doors rusted from inside out. Once you spotted it, it was too late and I don't want it to repeat.

Many owners on this forum did not think additional rust proofing is necessary because Jeep has done that from the factory. It makes sense if you trade your car in every 3-5 years and your roads are not salted.
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Thanks to all replies.

I read somewhere else about damaging bushings and gaskets and appreciate that davidevo50 for citing your own experience. I plan to spray bushings and gaskets myself with silicone before doing it.

I also read up on the warranty booklet and if I understand it correctly, Jeep only covers when rust eats through the metal sheet during warranty period. Therefore, the warranty effectively covers nothing.
I got my Jeep rustproofed at a Krown location in Mississauga, ON. I now understand why they wanted to drill holes in our cars.

They had one person to drive the car in. Once done, he also washed the car and drove it back out so his clothing would not stain the car.

The second person did the drilling and sprayed into door panels, hoods and hatches.

Then they got the car on a hoist, the 3rd person sprayed the underside and wheel wells.

They applied lithium grease to the drilled holes and plugged them tight and clean. I would overlook if I did not know what to look for.

This process allows them to move the cars along at good rate on busy day. Someone may argue that modern cars may already have access points but they can't not stop and look for those. The process took about 45 minutes.

I did not get a lot of drips because the cold weather froze the oil a little and our Jeeps have plastic cover panels running along the body. Those must have collected a lot of oil drips.

Overall, I feel better seeing how it was done, will see how the Jeep fare in the next 5-10 years.
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Question. I notice that rust proofing consists of filling the voids with a material that is resistant to rust, as well as the undercoating... But what about the metal lips around the doors and the hatch? What about the front lip on the hood? In my experience, the first things to start rusting are the edges of the doors, etc, places where you can't exactly rust proof. Or, do they do something I'm not aware of?

My last vehicle had rust proof foam blown into all the cavities and undercoating applied. While the extra protection did what it was supposed to do, I still had surface rust appearing in the nooks and crannies.

So, is it really worth it?
Krown uses thin oil that creeps into nooks and crannies that we don't see or reach, nothing else. They drilled access points where needed to insert a wand to inject the misty oil into the closed spaces. On each door, they drilled one high access point by the door handle and a lower one, you would see the oil seeps out the drainage holes and therefore it must get into the metal lip/edge around the doors. Included in the price was a spray can of their oil, I applied on the outside of the edges with a rag for extra protection.

The hood already has plenty of openings so they spayed liberally into those. You would see excess oil dripping onto your bumper from the front lip. The downside to this is it will take more effort to keep the engine bay clean.

I had a bad experience with my Mazda MPV, rustproofed from dealer. Rust started from inside door panels and destroyed the lower metal lips and ate through my wheel wells. They used a wax substance to seal the edges on doors and rear hatch but no protection from the inside. While the doors were bad, the hatch and sliding doors have no rust. I believe rain water penetrated into front door panels from the window seals and got into the rolled edges. IMO, Krown protection makes better sense in this regard.

They also sprayed upward when the car is on hoist, the oil should creep into gaps between body panels, front/rear bumpbers and into shock towers.

I think our Jeeps worth the protection but don't know how effective it is until years from now.
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I believe Krown has a different application for surface rust based on their price list but I would not bother. This may give Jeep Chrysler the excuse to wash their hands off any surface paint issue during warranty period.

Excluding issues due to external source such as stone chip, surface rusts indicated a manufacturing problem in treating the sheet metal and no rust protection will help us.

I don't want to sound like I am promoting for Krown but I have read countless pages of Krown-related postings online and there were people who had the same preference of cleanliness in the engine bay, they ended up asking the Krown guys not
to spray the hood ( then the Krown guys forgot the request).

The crimped edges on our Jeeps are very interesting, have you looked at them closely? My Mazda experience made me do this.

The horizontal edges at the bottom looked like they were double rolled then folded; the paint finish made it look like no seam at all, I was impressed. So I think we need to apply a paint protection that will shed moisture away at the same time.

The vertical edges were folded so technically moisture can still penetrate from both in and out direction so it needs a protection that seals. A protective barrier from both inside and out should work the best.

The inside of the edges can only be accessed from inside the door panel and again, we depend on the manufacturing process. If any gap there, only an oil film can form a protective barrier against moisture.

In summary, protection by oil film sounds good in theory but we will have to put up with drippings and annual application.
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Glad I live in high altitude arid desert.
The scrunity over small details sounds trivial but it also shows Jeep has done so many right things for our KLs. I was impressed to find a nice ATF cooler in my North/Lat model; I had to go after-market on my other vehicles with routing rubber hoses, screwed clamps and non-standard mounting brackets . The specs also listed an engine oil cooler which I intend to search for when doing my own 1st oil change.

The Cherooke could have gained better market share if they got us the right transmission from the start.
I should get my factory order sometime in the summer, and I'm considering getting Krown rustproofing when I get it.

This thread was started 2.5 years ago and some owners have had their Cherokee's over 4 Canadian winters now.

Anyone have any updates on how their vehicles has aged with Krown or without?

@JonnyVee, sorry I have not checked this thread for a while.

I had mine done within weeks of taking delivery, it was in Jan 2015. I was nervous at the time about the holes they drilled but it has been fine so far as the Jeep has been krowned 3 times since then. They replaced the plastic plugs each time and my Jeep drips for a few days after each visit.

I do the perennial maintenance myself and it was nice to see the underside rust free. I saw a YouTube video made in Ontario someone replacing his front brakes, could not help but notice some rust had started on that job.

You can review this multi-part YouTube video by Eric O on Krown Rust Proofing, it should answer many of our quesitons:

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