The relief value in the photo which OM posted came into being because of the shops and service trucks were using hi pressure air compressors, which were the cause of blowing out the seals in the rollers and as well as over greasing. And, yes there are now discontinued from Caterpillar. All of the over greasing was also one…if not the most reason for the 500 hour lube rollers.
By using the Alemite track grease gun (called a compressor), one can feel when the pressure is building up on the handle indicating the roller is full of grease.
Old Caterpillar Watch Fob.
Without history, a society shares no common memory of where it has been, of what its core values are, or what decisions in the past account for the present circumstances
David, Give CAT UK another call the Large Button Head Fitting is a CAT UK stocked item, if its out of stock at your local Cat Dealer they should be able to ship one in from another dealer within a day or 2.
Cat-Man (Byron) sent me the photo below, If you get stuck email Byron and I am sure he will send you one being a fellow UK Cat Collector.
Is that a CAT adapter? I don't have a name on the ones that I have. Could be Alemite. I don't know for sure. Here is a closeup of the relief valve. It is the same type of valve that is on the D6 9U or 8U water pump. The other two photos are of the first button head adapter that I got from the lubrication place that I went to seeking help. I hooked this to my Lincoln cordless grease gun and pump in grease til I head it come out. But, later on I learned that that was wrong and I probably popped the bellow seals in my D4 7J. So, I sought other adpaters that had the relief valve.
The picture is of a Cat part # adapter but most likely an Alemite product.
Seems any Alemite adapter with the side port (optional) threaded plug could be turned into a relief valve model with the installation of the pressure relief fittings (available from McMaster) providing the threads match up or could be tapped. Same arrangement as the water pump grease reliefs.
Be a good side project for someone as I'd think there is still a market for the old relief valve type.