OLDHAM COUPLINGS

[gasehound]

HI EVERYONE,LOOKING FOR SOME ADVICE. I HAVE RECENTLY BOUGHT A COMMANDER FROM A CHAP.JUST BEFORE PURCHASE HE FITTED NEW OLDHAM COUPLINGS ,NOW THE BIKE LEAKS WATER A LITTLE FROM THE LEFT SIDE. HE ASSURES ME THIS WILL STOP AFTER A FEW RUNS AND THEY BED IN. DOES THAT SOUND RIGHT ?.MANY THANKS.

[Richard Negus]

No, the water seal is leaking.Was it just the coupling replaced, or the pump overhauled which normally includes replacement of the coupling?It won't 'bed in', but just get worse in my opinion.R.

[Dell Boy]

In my experience a new water seal does sometimes leak until it "beds in". I have had this situation a few times including the last seal replacement 3 or 4 months ago. Ocassionally a drip of water will come out of the tell tale hole when the engine has been running very hot as well at any time, new seal or at high milage.Problem maybe lack of end float on the oldham coupling?Derek F.

[timharrison]

the leak is not because of the oldham coupling but will be the water seal. The problem is that if the coupling that wears out it cannot be replaced without breaking the seal and the chances of getting away with re-using the seal is remote. you will have to replace the seals unless they do "bed in". My experience is that the leak just gets worse. the seal usually holds when the engine is running but leaks when switched off. A new kit can easily be purchased from Graham at Startright, but as I understand it he can no longer obtain the imperial sizes so some machining may be required to accommodate the new size in the water pump housing. This could be a reason for attempting to change just the oldham coupling. The water pump system is pretty inadequate, you can be lucky and it will last for 10,000 miles as my current one has but I have in the past replaced the seals after less than 4,000. My Commander has done over 100,000 miles and since I bought it with 55,000 on the clock I have had to replace the couplings and seals 4/5 times. Tim