Well these projects are rarely over when you think that they are - and this one is no exception !
Having constructed the new reservoir, and given it all a jolly good clean out, I decided that it would be sensible to 'flush' the dispenser to make sure it's nice and clean before filing expensive gear boxes and axles. I happen to have a stash of brand new speciality oil that I was given, that all though very high quality and expensive is in a far greater quantity than I will ever use. So it got pressed into service as flushing oil. Scandalous really but it was expedient to use it.
So I rigged up a large funnel and a paint spraying filter, and put about 2500 mL in the tank. A clean filter at this stage so no contamination in the source oil.I then rigged the hose to direct oil back into the filter and proceeded to pump the oil out and back in.
To my horror the filter collected all sorts of particles. Non were magnetic but what the heck were they
![:scratch:](https://madmodder.net/Smileys/default/icon_scratch.gif)
I 'rinse and repeated' this process ten times and although the particle count had gone down there were still far too many - so what to do next?
I decided that the issue must be the pump itself - I hadn't dismantled it, and reportedly it wasn't serviceable but I obviously was going to have to dig deeper.
My plan was to pull it all apart, put some clean red diesel in a bucket, and use my 12 volt 'diesel transfer pump' as a 'parts washer' to give everything a good old going over. This would have been fine until I found that it had died a death - probably when I tried it on 24 volts in an attempt to move thick gear oil a few weeks back.
Admit defeat, chuck it in the bin and order another one -so I did. Well actually two to have one in reserve for the future. Amazon delivered them this after noon so play could be resumed.
Pulling the pump totally to bits revealed that the inner machined parts above the pinion housing as pretty foul, and the top valve in the piston was covered in crud. All got a very thorough washing in red diesel followed by a blow out with an air line and wipe with a clean rag to reveal anything missed. . . . All seemed well.
So putting it all back together having cut a new gasket for the top of the reservoir (thank you laser cutter!) I once more filled it up with the clean brand new oil through a paint filter which remained clean.
Imagine my horror when repeating the 'pump the oil round' trick the filter once more was catching particles - less than before but still too many. Again I repeated the flushing with a clean filter and on the third time round the loop very minor particles were caught - I'm sure that if I carry on repeating this process eventually it'll come good.
So at the moment it's on the bench and when passing I give the handle ten cycles of pumping (= 2.5 litres) and hopefully eventually all will be well - but what a pain.
The rack and pinion (both steel) are immersed in the oil, as is the aluminium piston and it steel ring. The particles are not magnetic so I can only think perhaps bits off the piston, or just maybe some coating that had been applied to the steel tube that I used for the reservoir - all a bit strange.