Lower Radiator Hose Leak???

[lambo]

I just finished replacing my radiator with a Nissens one that had, at most, 15 miles on it. When I finished buttoning everything up and was doing the bleeding, it started dripping consistently from the lower radiator hose so I stopped, drained it and checked all the fittings and such. This is when I noticed the receptacle on the new radiator is different, and possibly inferior, to the one on the old radiator. So I refitted everything, changed the hose clamp and tightened the crap out of it and now it's not leaking s much but it is still leaking...what gives? Is the receptacle the issue? Or is it the hose, or what? It's a brand new hose...

Here's the new radiator receptacle...



And the old one...



Thanks!

[Komzorz]

Looks like plastic, perhaps you overtightened it?

I guess you could get busy with the RTV until it stops leaking :|

[lcoleman]

If it leaks, your clamp probably isn't tight. No need to drain to tighten it...that bung looks fine.

[lambo]

Looks like plastic, perhaps you overtightened it?

I guess you could get busy with the RTV until it stops leaking :|

Overtightened? Would that cause an issue? Deform the hose or something?

If it leaks, your clamp probably isn't tight. No need to drain to tighten it...that bung looks fine.

I tightened the living hell out of it...I was scared of breaking the hose clamp...

[Komzorz]

Overtightened? Would that cause an issue? Deform the hose or something?

Could squash the plastic and make a weird shape that doesn't seal. With that kind of connection I'd probably do a tightness similar to a spark plug; won't get loose + just a little more.

[MR 325]

It should have that same ribbed fitting on it, I'm thinking your radiator is defective.

[jeffnhiscars]

The ribbed fitting is surely a better design. Rather than using sealant, which is just one more thing to go wrong over the life of a hose, I'd try using a double OE hose clamps as they are narrow enough to allow for 2.

[7pilot]

Overtightened? Would that cause an issue? Deform the hose or something?



I tightened the living hell out of it...I was scared of breaking the hose clamp...

In that case, by not correctly locating the clamp on the flange, you may have cut the hose.

Inspect the hose for cuts, change the clamp and locate the clamp just to the radiator side of the slash mark you can see on the hose flange.
You don't have to tighten the daylights out of the clamp if you locate it correctly.

m

[jlevie]

I'm going to have to say that either the hose is bad or there is a crack in the radiator. The lack of ribbing on this radiator has nothing to do with the seal of the hose. The ribbing is just for making a more mechanically secure connection. My first action would be to critically examine the radiator (with it out of the car). If I can't find a crack I'd try re-installing it with a new hose. If it still leaks, there is a crack in the radiator that I can't see.

Hint: Until you know that the problem has been solved, use plain water in the cooling system. That makes it easier to open up the cooling system as you can simply dump that onto the ground.

[lambo]

Well. I took the radiator out again and inspected everything. The hose looked fine, and I shaved off the casting marks on the radiator receptacles. Then I reassembled it and put everything back together carefully, I didn't tighten the hose clamp too much and I made sure it was sitting in the proper place...

It still leaks!

I'm going to try to use my old hose and see if that works. If not, it's back to my old radiator and I will never buy a Nissens radiator again, especially when a Mishimoto one is only 40-60 dollars more...

[lambo]

I'm going to have to say that either the hose is bad or there is a crack in the radiator. The lack of ribbing on this radiator has nothing to do with the seal of the hose. The ribbing is just for making a more mechanically secure connection. My first action would be to critically examine the radiator (with it out of the car). If I can't find a crack I'd try re-installing it with a new hose. If it still leaks, there is a crack in the radiator that I can't see.

Hint: Until you know that the problem has been solved, use plain water in the cooling system. That makes it easier to open up the cooling system as you can simply dump that onto the ground.

Well, I think you called it. Tried two different hoses and it still leaks. Back to my old radiator. Balls.

[zaq123]

Yes, old thread. Figured it will help someone.

Just had the same issue with Nissens radiator. It seems that the hose nipples on these radiators aren't moulded with any acceptable precision (You get what you pay for). OP had right idea to shave the mould seem but there is deeper issue - mould seem has not only raised edge but also a valley where the coolant leaks out from (in my case it was on the top).


What I did: used light coloured sharpie to paint the area of the seem. Use blade/sand paper to shave the area until the valley goes away. Inspect the radiator before the installation as this job would be much easier when the radiator is out. Do both (top and bottom) hose nipples/flanges as they are not perfect on these Nissens radiators. I used 120 paper and followed up by 400 grit. No more leaks

[zaq123]

To the above post...


Here is how this would look like in the middle of the process. Silver line (marker paint) is the valley/ low spot that needs to be taken down to stop the leak and allow the hose/clamp to seal the assembly

[lambo]

Yeah fuck nissens rads. Eventually ended up replacing the rad with a Behr Z3M radiator and it's been awesome.

[zaq123]

Yeah fuck nissens rads. Eventually ended up replacing the rad with a Behr Z3M radiator and it's been awesome.

I bought it a while ago for this e30 project and couldn't return it anymore hence the fix. Looks like no leaks after the fix so I'll take it. would I buy it again? Not if better alternatives are available