C5 Dewitts upper radiator hose interference
 

Wondering if anyone with a Dewitts in their C5 can help me figure out what I'm doing wrong. My upper radiator hose is getting dug into by the brake lines coming out of the ABS block.

There is a turn in the hose just as it exits, so it seems I would be able to rotate the elbow more 'up', but that results in the upper hose kinking badly as the hose bends to get under the air intake at the throttle body.

Maybe my upper hose is aftermarket (I'm the fourth owner of the car, so who knows) and not quite molded correctly???

I don't remember there being a clearance issue with the original radiator, but I'm not about to swap it back in just to check.

Anyone else have clearance issues in this area or any ideas what is causing my problem?

Tried to get some pics:

https://cimg6.ibsrv.net/gimg/www.cor...0c600b865b.jpg
https://cimg7.ibsrv.net/gimg/www.cor...6867ed3f3a.jpg

Thanks!

EDIT: forgot to mention this is a 2004 Z06.

Walt,

I've had the same issue on my 01 Coupe with a Dewitts. I've been running it like this for just over a year now with no issues but i've been keeping a close eye on it. I'm going to buy an extra upper hose on the off chance that something bad happens but hoping that nothing does.

The first thing I would check is how the radiator is fitting in its upper and lower mounts and whether or not it is tilted or located too far rearward. The rubber mounting blocks may need to be shaped or replaced to make sure it is located properly. There are two on the bottom and two on top and they may not be properly in place or they could have been damaged during the swap. I don't know about the DeWitts radiator but when I installed my DRM radiator I had to customize those rubber blocks due to the joint where the cooling section is joined to the tanks being slightly wider than the stock radiator that had plastic tanks. It wasn't a large difference in width but sufficient to require doing something with those blocks. If they weren't reinstalled due to issues fitting the radiator they do need to be in place.

Bill

Turn the hose up so it doesn't make contact.

Good suggestions Bill. This was the first thing I checked. The mounting 'tabs' at the top (and 'feet' at the bottom) are all sitting perfectly in their holders. In fact, I had noticed that the top rubber pieces are very slightly asymmetric, with a little more rubber in front than in back, so I already flipped those (which meant cutting off the little 'hold it in place' rubber nipple on each one that holds them in place to the upper mount for easier installation). That helped a little. But to move it any more would require fabrication of some sort. I'd only start doing that if there is no other solution. Sounds like at least one other person has this problem and is just living with it, but can anyone chime in that doesn't have this problem, and how they solved it?

As I mentioned in my first post, if I attempt to just 'rotate' that elbow as it comes out of the radiator the hose kinks, badly. If I had taken a wider shot you'd see that the upper hose is already tight against the rubber accordion air intake connecting the air bridge to the throttle body, so it can't be rotated 'up' any further. That's why I'm wondering if my hose is molded incorrectly or something if other people don't have this problem.

With my hose, if I remove the air intake at the throttle body as an experiment, to get the hose to clear the brake lines the hose runs right in front of the throttle, and the hose is kinked there because it's now bent more than it's molded to bend. If I then push the hose down to clear the intake, the kink moves to right at the elbow at the radiator, and it basically completely pinches off that hose.

Is there anyone out there with a DeWitts in their later-model C5 that doesn't have the upper radiator hose pressed hard against the brake lines?

I have the same issue. I cut a small section of the old hose and used RTV to hold it in place at the contact point of the brake line. There are two bolts holding the ABS to the ABS mounting bracket; check to be sure the ABS is fully seated into the bracket. I have no issues after four years. Maybe the hose shape is the issue. Is it possible a different hose manufacturer has it right?

I did notice the ABS mounting... mine is all the way down. I even thought about what it would take to extend the elongated slots to get it down further.

I tried putting a barrier between the hose and brake line (in my case some header wrap I had laying around) but I didn't like that it made my top hose kink that much more. It's already on the verge of kinking/pinching without anything else under it. But perhaps that's the best solution.

I asked DeWitts about it again using their on-line contact form.. I'll report here if/when they get back to me.

Try calling them - I’ve had wonderful experiences with them and would imagine they will work hard to get it resolved

You sure you didn't install the upper hose backward?

Anything's possible. I remember thinking when I installed it that it 'had' to go this way, but honestly, I can't remember exactly why.

I'd be more than happy to admit I'm an idiot if I've just got it installed backwards.

Can someone take a look at their upper hose? The way mine is installed, there is a 'peak' pretty much right in front of the power steering reservoir. I'd imagine that if I've got it on backwards, that 'peak' is in the wrong spot (it would be a 'valley' closer to the water pump, I think???).

Does this look right?
https://cimg9.ibsrv.net/gimg/www.cor...3dbfae775d.jpg

Guys, you really should send feedback to DeWitts or they will never know. Since I retired, nobody from Dewitts tracks the CF.

Engineering contact

jcdingman@dewitts.com

I don't know of difference between 99 and 04 zo6. But AutoZone uses the same hose on both. Mine does not have a curve like that in front of the PS tank. It runs across the bottom of the tank, not high like in the picture. Mines a Dayco hose.
With dewits rad. It has a couple inches clearance with ABS module and lines.

Edit: your module is different. The lines on mine go into the sides. It looks like yours go in the top?

Mine does the same thing on my C5 racecar. I installed the DeWitts during the middle of the 2014 NASA champs at Road Atlanta due to overheating the stock radiator. We finished the install around 1am, wrapped that part of the elbow in 4-5 rounds of Gorilla tape, and raced the champ race the next day. It has been that way ever since with zero issues. Same interference the first pics show.

I took my original radiator down from my attic to try to figure out what's going on here, and I think I figured it out.

The DeWitts radiator 'core' is slightly shorter (top to bottom) compared to the original. To make it fit, DeWitts welded slightly elongated 'mounts' to the top. But that essentially pushed the radiator inlet down with respect to the car.

I can think of two design fixes:

1. Get rid of these elongated mounts on the top and instead extend the ones on the bottom.
2. Weld the inlet on at a slight angle up so the hose isn't pointed straight at the brake lines.

I'll try calling DeWitts when I get a chance to see if there is anything they can do (or at least to give them the chance to make an improvement for future orders).

https://cimg1.ibsrv.net/gimg/www.cor...bf352df08b.jpg
https://cimg2.ibsrv.net/gimg/www.cor...a9a6ad45be.jpg

Here are a couple of pics. Hate to say but maybe spring for the ACDelco hose trusting Dewitts has got the rad neck and side tank positioned correctly. Your hose does pass the power steering reservoir pretty high but maybe your twisting put it there.

https://cimg4.ibsrv.net/gimg/www.cor...ecf092f70.jpeg
https://cimg5.ibsrv.net/gimg/www.cor...c3037e75a.jpeg

Just noticing your upper hose passes very low on the alternator. Are you sure you are not backwards on the install?

I'm pretty sure that the issue is just the radiator inlet is a little bit lower on the DeWitts than on the original radiator. My guess is that they developed it on an earlier C5 that doesn't have the brake lines right there. Others with later model C5's have chimed in that they have the same issue.