Lower radiator hose won’t go back on

[glin60]

Wrapping up install of B7 radiator on my B6 S4. Smooth install, right up to last step of reconnecting lower radiator hose. It goes on, but stops about .25 in short of clicking into place. I’ve tried lube, pry bar, you name it... all the stuff people talk about in other threads. Won’t budge. Not for lack of force, I’ll tell you that.

It’s as if something very solid inside the connector itself is preventing the connector from moving any further forward. I measured the radiator side of the connection beteen the original radiator and the new one and they’re the same.

Is there a trick? Or what am I missing? Is there some proper alignment nuance that I’m not hitting right? Or does this happen to failing connectors and the fix is a new lower radiator hose?


[IMG][/IMG]

I’m about 4 hrs into this particular fight.

Clearance from backside below. I don’t think that’s the issue.

[IMG][/IMG]

[924Carrera]

Provided the spring clip hasn't somehow gotten bound up and is in the released position, I guarantee it's just a matter of applying EVEN MORE force than what you think is reasonable. I've gone through this several times...the heater hose on the back of the crossover tube is another fun one. My buddy and I each grabbed a curved hose removal tool to hook against the backside of the plastic and both pulled with double handed death grip until it finally clicked on. The O-ring inside the end fitting is very thick and has to squish down a lot.

[glin60]

So I compared the depth of the bevel face on the lower vs the upper radiator hose. I noticed earlier that there was extra space where the O-ring sits. I also noticed a thunk when the connector stopped moving forward, as if it was shanking out.



So I took a depth measurement with the dial calipers. Depth of .36 in. I compared that to the upper radiator connector which fits smoothly without issue, and that measured .54 in. This is roughly the distance the connector doesn’t seat. Note in the pic below, how much space there is from the outer edge of the connector to the start of the bevel surface. Also not how there’s a smooth surface to all sides of the keyway for the index tab, unlike the lower connector.



My theory is that when removing the hose from the original radiator, it was more or less bonded to the original radiator and when I forced it off, it caused the bevel to migrate outboard. Further evidence for this can be seen by the lack of spring clamp slots inside the clamp, forward of the bevel. It appears the bevel now covers these slots. I previously assumed these were CNC milled and the bevel would not migrate, but based on this, it appears not?

Anyway, I look at this with two solutions. 1) replace lower radiator hose, which replaces the connector. Or 2) find a way to force the bevel surface back inboard. This surface may be press fit, so without a press, the amount of force required to press the original back into place might be a lot, probably more than can be generated in situ. Either way, looks like I’m pulling a lower radiator hose.

Thoughts?

[924Carrera]

Makes sense. It's probably why my heater hose in particular was so hard to get back on, but with the force of two people yarding on it, it probably pressed that bevel back into place. The lower radiator hose thanks to its intricate branched design (and that complex end fitting) is comically expensive (for a hose, anyway), so I would definitely try to press that bevel back into place before just buying a new hose unless it's showing signs of leakage or wear. If you don't have a buddy to help pull on it or even that doesn't work, then I guess taking the hose off and trying to press/pry the bevel back into place would be worth a shot.

[jmcS4]

You're over thinking this. make sure the spring clip is on and take 924Carrera's advice and push harder. Ive had the same issue when i first encounter this type of fitting a long time ago. gotta use force. they're even more fun when the spring clip rusts and deforms then really gets stuck.

[Grigor@Bestiale]

Why don’t you remove the o-ring and the metal spring clip and try to put it on and see if it goes all the way in?
If it does: lubricate the prong with coolant excessively and the flange too that it goes on and push the hose in like there’s no tomorrow :-), but be careful not to f up the radiator


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[JimmyBones]

So I compared the depth of the bevel face on the lower vs the upper radiator hose. I noticed earlier that there was extra space where the O-ring sits. I also noticed a thunk when the connector stopped moving forward, as if it was shanking out.



So I took a depth measurement with the dial calipers. Depth of .36 in. I compared that to the upper radiator connector which fits smoothly without issue, and that measured .54 in. This is roughly the distance the connector doesn’t seat. Note in the pic below, how much space there is from the outer edge of the connector to the start of the bevel surface. Also not how there’s a smooth surface to all sides of the keyway for the index tab, unlike the lower connector.



My theory is that when removing the hose from the original radiator, it was more or less bonded to the original radiator and when I forced it off, it caused the bevel to migrate outboard. Further evidence for this can be seen by the lack of spring clamp slots inside the clamp, forward of the bevel. It appears the bevel now covers these slots. I previously assumed these were CNC milled and the bevel would not migrate, but based on this, it appears not?

Anyway, I look at this with two solutions. 1) replace lower radiator hose, which replaces the connector. Or 2) find a way to force the bevel surface back inboard. This surface may be press fit, so without a press, the amount of force required to press the original back into place might be a lot, probably more than can be generated in situ. Either way, looks like I’m pulling a lower radiator hose.

Thoughts?

The bolded theory is correct. Push the plastic bevel back into the fitting closer to the o-ring and install the hose. I use a flathead screwdriver or pick and it is pretty easy. This happens to me on cars that have not come apart before and is frustrating because it takes me a second to realize it why the hose will not go back on.

[kabukie]

My lower hose was a PITA to get back on. I struggled with it for at least 30minutes. Used a lot of swearing and eventually a long screwdriver to use as leverage to push the hose into place.

[DarrenOman]

You needed to replace my O ring to get mine back on. I think they expand with the heat over time. Super easy with the new O ring.

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[Grigor@Bestiale]

Btw you ARE using a new O ring, right? I do every time I remove any (I think Audi says they must be replaced once removed too)


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[Shector]

I’m having the same problem connecting my lower coolant hose back to my water pump . Even with the pump In My Hand it won’t budge. I take of the O-ring and it pops right on so what’s rlly the problem?

[Zolli]

My lower hose was a PITA to get back on. I struggled with it for at least 30minutes. Used a lot of swearing and eventually a long screwdriver to use as leverage to push the hose into place.

Ample swearing and a long-ass screwdriver were my tools of choice, too. I almost bought the Schwabein swear words and long-ass screwdriver kit, but I just opted for good ole American brute force. I also lubed the new o-ring with spittle generated from my R Lee Ermey impression while I was yelling at it.

After such gentle persuasion, I got them connected. You got this, OP 💪

[Zolli]

....or new op with the necro-bump

[Jdsb6s4]

apply a small amt of vasaline on the rubber o ring... pops right back in easy. Unless the new radiator came with another hard plastic ring and you are trying to press that back on with the pre-existing hard ring connected on the o ring side, that could explain why its not going in all the way

[evildsmr]

apply a small amt of vasaline on the rubber o ring... pops right back in easy. Unless the new radiator came with another hard plastic ring and you are trying to press that back on with the pre-existing hard ring connected on the o ring side, that could explain why its not going in all the way

^^^^^^ This all day. I put grease similar to this all around the connector on radiator side. Slides in easily every time.

[Zolli]

Wow you guys used Vasoline/grease on the coolant o-ring? I Always thought that grease and coolant are baaaaaad to mix..... I’m no expert, just asking for my future self

[Jdsb6s4]

Wow you guys used Vasoline/grease on the coolant o-ring? I Always thought that grease and coolant are baaaaaad to mix..... I’m no expert, just asking for my future self

It’s such a dismal amount that it’s not going to cause any issues.


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[steve53mg]

I just went through this. I found that even kn the out position, it still interfered with the fit. When I pulled the spring clip past the stops, it went right on.