Fan belt rubbing on lower radiator hose.

[rswaffie]

Hi,
I have had to replace my lower radiator to water pump hose due to the fan belt edge rubbing on it until it wore through.



Whilst there appeared to be clearance between the belt (as it passes around the tensioner pulley) and the hose when the engine is off, the lateral movement of the engine when running causes the tensioner pulley to allow the belt to rub against the hose. I can’t increase the tension on the belt (to move the tensioner pulley away from the hose) as there is no further movement available at the alternator.

I’ve tried to increase the gap when fitting the new hose, but I can’t get the required clearance. I can see that the new hose is still getting rubbed once the engine is running.

I’m running a 1010 duplex belt and I have read on here that I don’t actually need the tensioner pulley so if I ran a smaller belt and bypassed the tensioner, it would solve this particular issue.

Does anyone know what size would be appropriate? SNG do a 940mm - would that fit?

[abowie]

Very common problem.

You need to adjust the two pieces of hose on the intermediary steel pipe so that you get clearance and still clear the steering column UJ .

On one of my cars I have put a hose clamp around that section of hose and squashed one side flat so the hose is sort of a fat D in cross section there.

Taking out the tensioner is the other option but your problem should be fixable by moving the hose. From memory you need about 2cm less belt, but I'm not sure if you'll find one in the duplex belts. I have no tensioner on my 3.8 coupe but I have standard V pulleys fitted on that car.

[rswaffie]

Thanks Andrew.
I’ve ordered a shorter duplex belt, but I’ll have another go at moving the hoses in the meantime.

[abowie]

Thanks Andrew.
I’ve ordered a shorter duplex belt, but I’ll have another go at moving the hoses in the meantime.

It's a faff but it should be possible.

[rswaffie]

By way of an update, I tried a shorter duplex belt (1010mm) but that still didn’t tension the pulley enough to move it away from the hose. Tried an even shorter belt (940mm) and bypassed the tensioner pulley but even with the dynator slackened off, the belt was too short.
So, drained the cooling system and removed the lower hose from the water pump and the intermediate alloy ‘elbow’ and cleaned up all the mating faces and applied some red rubber grease to each section of hose. I then managed to manoeuvre each joint to get the entire assembly away from the pulley. I also didn’t push the bottom hose to water pump section all the way up the pump inlet, which added some extra clearance. Refilled and been out for a test run and everything seems to be staying in place, no rubbing or leaks and the steering column joint isn’t fouling. I’ll keep an eye on it over the next few weeks as I’ll be putting some more miles on the clock.