05-05-2005, 10:35 PM
This has happened 4 times now. The metal water return hoses keeps blowing off after a few minutes of running. (Not moving). 3 times on the lower and once at the top connection. Used a wire style clamp off a Ford with hex head and tightened the hebee geebees out of it. Then the top on blew off next. I'm using brand new green hoses from TRF with beveled 9mm wide BMW style clamps.. No water is coming out the overflow when the cap is on. So I don't think it's over heating. How can I fix? Is this common?

05-06-2005, 07:13 AM
What are the outlets on the radiator like? Are they very smooth or chromed, if so that could be your problem. Otherwise, try doubling up on clamps, and space them about 10mm apart.

05-06-2005, 08:46 AM
This happened once to me a number of years ago, but only with the lower radiator hose. The car was idling in the driveway when I heard water rushing onto the ground. Apparently, the engine vibration worked the hose off the s.s. return pipe, as I must have had the hose too close to the edge. I just placed the rubber hose further up the pipe and clamped it tighter.

05-06-2005, 06:26 PM

Is this happening on your TR3 or TR250?

The reason I ask is that the TR3 should only have about 4 lbs of pressure in the coolant system. Fully warmed up, the radiator cap should allow excess coolant to escape if over 4 lbs.

I think the TR250 uses 7 lb system, which is only slightly more. Many modern cars are 14 lbs, 20 lbs and more. The low pressures of TR cooling systems should not be blowing off hoses, if the system is circulating properly and not over full!

You mentioned it's after a few minutes idling, but is the car fully warmed up, the thermostat fully open?

Check the radiator cap for proper release, or just replace with a new, correctyly fitted one. Check that the system isn't over full. Check that the thermostat is working properly. Check that there aren't obstructions some where in the system.

Have you recently replaced the thremostat? Is it in backwards? Does it have bypass holes in it? What is the temperature rating of the thermostat?

Do you have the bypass hose blocked off because of the problem getting a sleeved thermostat?

Hope this helps!


05-06-2005, 06:53 PM
After you verify that the thermostat and radiator are not causing some blockage you might consider adding some small lips to the ends of the steel pipe. I have used 14 gauge copper electrical wire wrapped into a donut and soldered it to the end of the pipe. The hose still slides over it but now when you clamp it - the slight knob prevents it from coming off. Use some good wide stainless steel band clamps and leave those wire clamp jobbies on your Ford (where they belong).

05-07-2005, 06:56 AM
Hi again,

If the cooling system all checks out alright, perhaps some Hylomar sealant on the pipe and hose would help keep the hoses in place. Just put a thin layer on the pipe or the inside of the hose, slip together and let it set up, about an hour. It might make disassembly more difficult later, though.