Oil Pump Springs differing lengths??

[Michael.Brown]

Hi all,

In sorting out my lack of oil return, I have taken the Oil Tank off, cleaned the tank and the Oil Filter and made sure all oil ways are clear. I have removed both feed and return pipes plus unions and made sure there are no blockages. The Sump came off next (very small amount of oil in the Sump plate) and the filter has been cleaned.

The Oil Pump was removed and I have established clear oil ways between feed and return unions and Oil Pump holes. Similarly I have blown through the Scavenge pipe in the Sump to the Oil Pump hole. Behind the Oil Pump was a spring loaded Ball Valve leading in to the timing chest? I didn't remove and clean it but made sure it was operating by pressing the ball against the spring pressure.It felt ok.

I dismantled the Oil Pump and re-seated the ball bearings by lightly tapping them on their seats. The two springs in the Pump are different lengths (different no. of coils and gauge of wire) although in action appear to give a similar resistance. Should I replace these? The Pump seems to be in good condition with no rock on the individual plungers.

The only oil way I couldn't check was the feed to the big end? but it looks clear as far as I can see. Any way to test that one? Or am I being to thorough.

Mike

[nevhunter]

I would replace the balls . They are an odd size and sometimes wear out of round or could have been fitted with the incorrect diameter. Hard metal is often worn by softer metal. With very light oil check that each plunger "pop" when operated especially the smaller one which if it leaks has a smaller output to start with. Check the sludge trap in the flywheel. You can get at it with the sump plate off. and also operate an oil can into the crankshaft end in the timing case and observe it run through the big end with the sump plate off. The copper pick up pipe should be checked for leaks it can crack. Put a rubber hose on the bottom and block the top and suck on it It, put the end of your tongue over the hole and check that it hold the suction. Also should have the extra thin"ring" paper gasket on the contact face of the crankcase and cam cover fitted over the copper pipe extension .. Regarding the springs in the pump. There are some crook types around. The originals are tapered and not particularly strong or long and don't bend. Fit in carefully so they don't foul the threads. They work the best. Nev

[simon.holyfield]

Mike,

The only way I know to check the feed to the big end is to pump oil down the crankshaft and see it fall through the sump plate. You'll have to take the timing case off to achieve this, but its useful.

[Michael.Brown]

Thanks for all your advice and suggestions guys.

I have since removed the rocker feed and checked all oil ways are clear and just to be extra sure I have injected oil into all the oil pump galleries (behind the pump) and made sure all are passing oil correctly. Just this dodgy spring in the pump to replace and I should be good to go.

Mike

[paul.jameson]

Mike,

Having rebuilt the pump with new springs and balls hold it joint face upwards and put on eye protection. Squirt some oil over the joint face and pull out the plungers so as to get the pump full of oil. Smartly depress each plunger fully in turn. If the pump is working correctly you will know why I suggested eye protection.

[Michael.Brown]

Hi Paul,

I had to laugh at that. I cleaned out the pump yesterday and this morning primed it with oil, checked the suction first and then depressed each plunger in turn with the upper hole closed off with my finger. I got a face full of oil from each of the lower ones! Not content with doing it once I did it twice! I was so pleased I didn't swear.............................honest. It certainly comes out at some velocity.

Mike

[nevhunter]

Don't close the "upper" holes. You invalidate the test The plunger only strokes a small distance past those holes, and that's where the oil comes in (and goes out till they are sealed off by the plungers) in use. Use thin oil also or a mix of diesel or kero to test how it will work when hot and the oil becomes thin. The delivery pump being much smaller,(especially the earlier ones) is more susceptible to leakage and reduced performance. Nev