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why do I have coolant leaks at all hoses? 900

1993 945T 95K. I replaced all of the cooling system hoses and hose clamps. The previous owner replaced the radiator with a niessens. There were no leaks before replacing the hoses. The leaks occur at the end of most of the hoses, as if the clamps are not tight enough. I have tightened them quite a bit and think that they should be tight enough. I also replaced the expansion tank cap twice. Now I have a low pressure black one. The pressure in the system does not seem that high as I can squeeze the hoses without too much effort (when car is warmed up). I thought that it might be because I used aftermarket hoses. So I replaced the lower radiator (three way) hose with a Volvo part ($$). This leaks a bit less, but still does. Could it be the aftermarket hose clamps!? They seem to be of decent quality (all parts from FCP groton). The clamps are of the kind where the threads are on one side of the belt and don't pass through - so as to minimize damage to the rubber hose. I am at a loss. I am using the orange prestone coolant. I replaced the cooling system parts in my 740 before without a single leak.

One of these days, I hope that I will have the car working the way it should.

Thank you,
Steve
--
1986 745 w/ M46 200K since new, 1995 965 104K








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    why do I have coolant leaks at all hoses? 900

    One thing I've found over the years is that first of all, all factory hose clamps are garbage and should probably be thrown out after one use.

    The stainless steel replacement clamps commonly sold seem to work fine, but may require extra tightening for tough applications. We use these all the time where I work, in all kinds of applications and exposed to all kinds of moisture, vibration, heat, and chemicals, and they are rarely a problem.

    The bolt heads on the hose clamps are almost always 5/16, which is almost exactly 8mm. I tighten them using the socket of a 5-in-1 screwdriver rather than a flat-blade bit. You can get MUCH more torque on them and not slip off into a hose, the radiator, or your hand. Sears sells its version of this screwdriver for $5, often at the counter of the hardware dept. Handy tool, everyone should have one. Any other kind of 8mm or 5/16" socket can also be used, whatever you have that fits and works in the location.

    You have a nice replacement metal radiator, but original plastic-tank radiators MUST NOT be over-tightened at the water necks, or they WILL break, and you WILL overheat your engine.

    Good luck with it.
    --
    ::: Rob Bareiss, New London CT ::: 92 244 ::: 90 745GL ::: 90 745T ::: 84 242DL ::: 90 745T Parts ::: Used to have : 86 244DL, 87 244DL, 91 244, 88 244GL, 88 744GLE, 82 245T, 86 244DL, 87 244DL, 88 245DL, 89 244DL!








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    why do I have coolant leaks at all hoses? 900

    The "orange" Prestone coolant is Dexcool, which unfortunately finds leaks wherever they might be had. Your best bet is to replace the coolant with Xerex G-05, which has a better anticorrosion package and does not tend to leak. And clean off the fittings before reinstalling the hoses: remove all old gunk by gently scrubbing with a plastic scouring pad. Make sure the hoses fit snugly and fully on the fittings and that the clamps will adequately torque so that the band is snug over the hose end. And also: position the hose clamp so that it is about 1/4 inch from the end of the hose but not above the lip on the end of the fitting: it squeezes the hose between the lip and the base of the fitting.







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