New Radiator Hoses Leak
 

Hi all,
Has this ever happened to you? When I got my car, it had several coolant leaks that I went through and fixed. One issue was the radiator, it was old and leaky, so I got a new replacement from rockauto. At the same time, I figured I might as well replace the upper and lower hoses. Now I can't get the damn hoses to "seal" up for the life of me. Sometimes I can get it to stop leaking by undoing the clamps (new) and re-seating the hose, but it will always start leaking again. Mostly on the engine side of both top and bottom hoses. I feel like the hoses are too big for the flange or something, but IDK... I even put two clamps on the upper hose side...

When I got the hoses, I had a hard time finding them. O'reilley was the only place that had them, and they had to order them. Am I missing something? Anyone else have this issue?

Did you dress up the surfaces where the hoses attach at the waterpump? I usually take some
00 steel wool and try to make it as smooth as possible and shiney.

Are you clamping behind the bulge on the hose mount or right on top of it? Make sure you clamp
behind the bulge so it forces the hose to bend over the bulge, that helps seal it as well.

Thanks Tim,
I did that stuff; wire brush on the surfaces, at least on the T-stat one. The lower looked in better shape, and was a bit harder to get to. The T-stat one still leaks though, probably more than the lower one. I've also moved the clamps around trying to get a better seal - nothing seems to work for long. Maybe I need new inlet and outlet fittings? Is that possible to get those? I briefly considered rtv, but I think that would make my life hell if I needed to get the hoses back off.

what pressure cap is on the new radiator? are you over pressurizing the system? just a thought

What type of hose clamps did you use?
This happened to me recently and it was because I used fancy stainless clamps from the local hydraulic store
Once I used regular worm gear clamps I got everything to seal up
And stock spring clamps were only made to be used once. Toss those out

Hmm.. I'll check the rad cap. I didn't replace it, but it has been replaced at some time in its' life. Might be a PO used a higher pressure to try and get some cooling issues under control.

Yeah, I used the worm gear type. I guy at the auto parts place told me to put some rtv in the screw mechanism to help keep it from backing off, but I haven't done that yet for fear of a mess.

Thanks for the ideas guys!

Dumb idea. A good worm gear clamp won't have this issue.

Speaking of which I have used some that are so bad that they strip out really
easily and after tightening they pop back off a bit and don't seal as tight as they
should.

Yeah, a worm-and-rack mechanism can't run backwards (rack moving the worm) unless the thread pitch is almost parallel to the worm axis - less than 45 degrees IIRC - - at which point the worm starts to resemble a pinion.

Sounds to me like the hoses are just to big of a diameter. Autozone has the upper. I couldn't get their lower to fit.

I seem to remember thinking the hoses felt big, though they were the right shape. Maybe I should get an Autozone hose and see if it fits any better. I'll check the cap pressure first see if that is correct.

clykins: Out of curiosity, why didn't the lower fit for you?

Just FYI, my cooling system rocks otherwise. Gauge stays a tick over the first hash line in normal cooler day driving. In the summer, it gets a tad warmer, but never gets even close to center.

The lower didn't work because it would bend correctly over the front engine mounting bracket.

I meant to update this earlier. I like to keep the outcomes in these threads up to date so that someone later on can know the answer.

I took the upper and lower hoses completely off, and cleaned the inlet and outlet of the engine with a wire brush and some steel wool. There was some rust build up so I think that helped. The biggest thing I noticed though was from my own fault. When I took the lower hose off, I noticed that I had the clamp ABOVE the bump in the pipe. Doh! I must have been looking at it upside down when I installed it and got confused, which is easy to do for me. (Ever have one of those times when that bolt just won't come loose no matter how hard you bang it, then realize your going the wrong way? - Yeah, that's me.) I put that clamp back on correctly, and with all the other stuff I did, it seems to be leak free.

Thanks to all who gave input :-)

So the hose clamp position was the problem, not the hose itself? I ask because I just installed all that stuff today and will throw on the hose clamps tomorrow.

I think so. I was mostly seeing coolant on the tray and at the bottom of the lower hose. I could see where there was a dried trail coming from the lower intake side and running down, so it was def leaking there.

But.... I always had a little on the outlet flange as well, and I think that is because the flange was rusty and, I just didn't spend enough time cleaning it the first time I installed the hoses. It was still very pitted, and I am still using two clamps on that hose. When I cleaned it this time, I really spent a lot of time getting it as smooth as possible, and I also cleaned the insides of the hoses where the rust had stuck fast to them.

I usually take a wire wheel on a drill to the outlets on the water pump assembly
until its all shiney and smooth. Bumps and limps are ok as long as they are smooth.
I do this with any car that has metal water pump outlets. I also use a smaller wheel
to go inside as well.

I used two clamps to solve the lower radiator hose leaking problem. If the clamp is over tightened, then it radiator outlet flange starts collapsing.