radiator neck problem

[quawk]

After replacing the split reducing connecting hose from the filler neck to the radiator neck and adding coolant to bring it up to the proper level, I noticed that the coolant would start filling up the filler neck to the top without first entering and filling the small expansion tank. I removed the filler neck, the reducing connecting hose, and the small expansion tank again to look for the problem. As I suspected, the small 90 degree bent tube/nipple coming off of the radiator neck was plugged solid with what I suspect was dried and hardened coolant. Unfortunately, even though I was careful, during removal of the hose from the tube to the expansion tank I cracked/loosened the joint between the small tube and the radiator neck. It was one of those "I was afraid of that" moments. Upon trying to clear the tube of the blockage, it of course broke clear off the radiator tube. It doesn't look to be brass so is it and the radiator neck aluminum. I didn't try putting a magnet on it. Anyway any suggestions on what will need to be done to reattach the tube to the neck. I of course would like to avoid taking it to a radiator shop but will if I have to. I can braze and solder, but if it's aluminum then what? Probably not the best choice, but I might even give JB Weld a shot.

[wayne]

Unfortunately it is aluminium. Same problem.

To fix, I had a junk radiator and cut out the small tube along with a dime sized circle out of the filler neck from the donor radiator. Then got a shop to weld it. Wasn't costly, a solid repair. The tube on the first radiator was badly damaged as the owner had destroyed it trying to remove the radiator without realising those tubes were there and attached to the overflow tank.

If your tube survived in good condition, I'm sure a shop could weld it back. I didn't use a radiator repair guy, just a local welder.

[quawk]

Thanks Wayne for the response and relating how you solved the problem. As I said in my post, I was very careful removing the small hose from that tube because it looked like it was just begging to be broken off, BUT the worst happened anyway. Has there been other posts or have you heard personally, is the plugging of this small tube somewhat of a common problem. I would suspect that bikes that have sat in the shed, barn, garage, or wherever for extended periods of time may experience this. Being such a small diameter would probably contribute to the problem. Although I do have a second bike which I have not had a chance to even touch or work on up to this point, it is nearly complete and is much more than a "parts" bike. I would only rob the radiator off of that bike as a last resort but there would be the possibility of the same thing happening to that one. 

[wayne]

Blocking of those tubes is common. I've come across exactly the same, hardened deposits in the tube. I don't use expensive coolant myself but do make sure it's correct for the job and change it every two years regardless of the manufacturer's claims. The system remains internally very clean. Don't forget to add the Bar's Leaks as prescribed in the owner's manual.

There's been at least one person on this forum who simply blocked off the pipes and ran without them and the overflow tank.

The tubes aren't that fragile. I think the work of previous owner's has in some cases damaged the tubes just waiting for the day you try and carefully remove them. Tubes in good original condition will survive multiple removals.

[quawk]

I'm glad you mentioned the prescribed addition of "anti-leak compound" as I was unaware of this being prescribed by Suzuki. I overlooked this in the owners manual. I also find this curious that this would be recommended as any time I have used this product (Bars Leak) over the years, it was because of a confirmed leak being present in a cooling system. I never used it as a "just in case" or preventative measure. I can't help but think that this would contribute to the plugging of a small diameter passage such as the radiator tube we've been discussing in this thread.

[wayne]

I've been told it's not about leaks, it's about lubrication. A common problem in the RE's cooling system is the shaft tip bearing on the waterpump. I've always used Bar's Leaks and my bearing was in excellent condition. I've seen some badly worn bearings in bikes with fewer miles and have wondered if it was a lack of the addition.

Pretty sure Suzuki also specified it in the GT750 waterbottle, not just an RE5 thing.

[gtdude]

Suzuki also called for it in the 1985 - 88 Cavalcade.

                       GT dude

[quawk]

As I mentioned I may consider doing at the start of this thread, to repair the broken off 90 degree bent tube/nipple on the radiator neck of my bike, I did go ahead and try JB Weld for the repair. After reassembling everything, refilling the cooling system, and starting and running it up to operating temp repeatedly, so far there has been no leaks. Don't know of course how this will fare over the long term but for now it's good. If it leaks in the future I'll deal with it some other way. I used JB Weld steel stick epoxy putty.