Upper coolant hose problem

[kruat]

So, last week I took the RS out for a quick trip to my sons school to pick him up. Got on the highway, goosed the throttle and blew the upper coolant hose off the radiator. Thought I might have broke the plastic outlet off the radiator, but luckily looks like the hose just came off.

So I put the hose back on, at least I thought I did, and waited for my coolant pressure tester to arrive. Got the tester, pumped a little over one bar of pressure into the system, and checked the upper hose. It literally blew off again when I wiggled it a little bit.

So, am I being a dummy, and not putting it on correctly, or is there something else. I looked online, and found out that you apparently can not get a new OEM one anymore. Great. So, what should I do. Replace gasket? Replace the metal "C" clip?

Any thoughts?

https://www.audizine.com/gallery/data/500/medium/20210429_194029.jpg

[DKP]

When I had my engine out not to long ago I’m almost positive we were able to get the upper radiator hose. However I did replace every other and I mean every intake hose, HVAC hose vacuum hose etc. We ordered every hose on the car from a Swedish company called do88. Quality stuff and lighting fast service. I believe they send the coolant hoses and that one you show if I remember right you have to recycle the hard parts and use do88 hoses to basically repair the set up you show. And for that reason we went with the oem one to avoid all the additional connecting points. Google the company and see if they can work for you.

[DKP]

Wait I lied. Just went to the garage to have a peek. We did use their hose kit and recycled the OEM hard bits.

[hahnmgh63]

You do have to push it on all the way, sometimes it's tight, before you pop the spring clip down.

[kruat]

Ya thanks for the reply. I believe the "hard" part is where I think I have a problem. The hose seems fine, only have 55k on the car afterall.

I think I'm gonna try a new gasket and c clip.

What's the max pressure for an OEM coolant system?

[Muggy]

I'd take a closer look at the spigot on the radiator...your clip looks perfect, so I doubt that it is an issue, but doesn't hurt to replace. I guess it's possible that the lip on the plastic spigot could be rounded a bit where this is supposed to clip on and hold. When you put back together, I'd lube the o-ring just a touch so it slides on easier as it is a snug fit...I hate plastic parts, especially on the ones that are heat cycled so much over the years.

I've heard that there is something out there called a zip-tie that can do wonders with custom fabrication...:stick:

Honestly though, maybe it's time to push on the aluminum rad upgrade if you continue to have a problem.

[hahnmgh63]

I've been planning on contacting CSF radiators as they've been making a all Aluminum perfromance radiator for the B5 S4 for a few years and just started making one for the B8 S5/S4. I've all but given up on Wizard as they have not replied to my last 3 E-mails, guess they have all the business they need.

[kruat]

Little update:

So I think I realized my issue. When I had the front clip off, doing the timing belt, I removed the upper coolant hose of course. I did not remove it from the hard coolant line at that time. So what I realized was that because i didn't take the hose off the hard line that runs to the back of the engine, I didn't have a lot of wiggle room in the hose. If that makes any sense. Basically, because it was stuck on the hard pipe, it only allowed me a little bit of play to attached the hose to the radiator.

But now, since I completely removed the hose, it donned on me that could be the problem. So, yesterday, I attached it to the radiator first, pushing it as far on as I could, then attached it to the hard coolant line.

I pressurized the system to 1.5 bar and wiggled the hose and nothing, not even a drop in pressure. Filled with coolant, burped the system, and took it for a drive. So far so good.

[DKP]

Always love a happy AND inexpensive ending to a story.