Two Leaky Heater Hoses

[dalybo]

I replaced all the coolant/heater hoses plus the thermostat on my 1996 NSX. All is dry, except the two heater hoses up front. The leaks are coming from the ends that attach to the brass pipes that penetrate the firewall. I have tried realignment of the hose clamps and hose pushing and shoving to no avail.

 

[Briank]

Did you scratch the pipes when you cut off the old ones?

 

[pgilliam1]

Did you perhaps stretch the clamps when you removed them?

 

[dalybo]

Thanks fellows for these two not so obvious reasons for the heater pipe leaks. Thinking back on the hose removal/installation process, I suppose that I could have scratched the copper pipes with my exacto knife. I do not recall have much difficulty removing these two clamps, but I have thought about replacing the clamps with new ones in the event that I did over stretch them during the removal/reinstall process.

Another question, does it matter much where the hose is placed on the brass tubes. They are flared at the ends and I was wondering if the clamps should be closer to the flared end rather then the firewall end of the hose?

 

[Huck]

The flaring of a brass tube is more for fitment and hose slipping off rather then sealing. Assuming you have the correct hoses on the tubes--they should fit on snug, then claming should correct any leakage issue. If you scratched the tube--you could have a bit of a leak butttt ususally a good clamp will squeeze the hose enough to fill a void left by a razor scratch. Worse case would be you need to pull the hoses and use some sealer on the tube/hose before reclamping. Make sure the clamp puts enough pressure on the hose for it to buldge just a bit on either side of the clamp----.

 

[d.n]

Yeah I'd be surprised if a razor blade mark would cause a leak unless you really dinged it. You could try one of those after market screw type clamps if you can reach it (not sure if you can reach it in there).

Worst case, some honda bond in there actually will work. I've done that to seal a dented tube on another Honda and to my knowledge it's still fine after 10yrs. I only applied a light coat on the tube side

 

[dalybo]

I replaced one of the original Acura style spring action clamps with a screw on type clamp and all is dry. Thanks to all of you for your guidance.

 

[A.S. Motorsport]

#6 HOSE, WATER INLET (WATER VALVE) 79721-SL0-A00
#8 HOSE, WATER OUTLET (HEATER) 79725-SL0-A00
#9 HOSE A, WATER JOINT 79726-SL0-A00

 

[andrea]

At least on earlier 4.7s there is a rubber section of hose that connects to the water pump. It then transitions to a metal tube that goes over the top of the engine to the LH side where the heater hoses connect. For both the supply and return to the core.