Stihl 009 Oil Pump Problem

[trevdalocal]

I'm working on an old 009, runs great now, but doesn't pump any oil. Replaced the diaphragm and gaskets with Sawzilla Proline repro parts, still no joy. Air blows through the hose easily, I've snaked it with a small wire, I even took it out and inspected for cuts or cracks. I cleaned out the check valve, test shows it passes air going into the saw, but will not in the other direction, which seems correct. I used an Oxy Acetylene torch tip cleaning wire to press the ball in the check valve, it moves freely and springs back. I noticed that the pin on the diaphragm, both old and new, do not reach that check ball and press on it. They are both too short by 1/16" or so.

At first I thought this was okay and design was to have the pressure of the oil overcome the check ball, but thinking about it more, I don't think that's the case. I think the increased surface area of the diaphragm is needed to generate the force to push the check ball down. Does anyone recall if their diaphragm pin presses down on the spring loaded check ball when fully depressed in the oil pump body? That's the only thing I can think of at this point, I've gone over every other aspect of the oiling system.

Thanks!

 

[hotshot]

These guys would know the correct OG plunger length & operation answer. Give them some time to respond as they’re in Germany.

https://www.arboristsite.com/thread...1-012-and-oilpump-diaphragm-available.355414/

 

[trevdalocal]

@ChainSawFlo
Do you have any insight on this, if you don't mind?

 

[trevdalocal]

Bump for any advice...

 

[trains]

Going by memory, the plunger pump/ pin does not need to push up against the ball valve, its the pressure of the pump that moves the ball and allows the oil to pass it.
is the ball clean, and where it seats clean, if not, it wont pump if it doesnt seat correctly, old oil can oxidize and cause it not to seat.

edited to add

in the pump housing, are the oil delivery holes clear, where the pump draws in oil into the pump chamber, have seen them blocked too.

Just catching up to where your at, since we have no pictures of said pump etc.

 

[trevdalocal]

Thanks for the reply. I believe the ball to be clean, it holds up to low pressure compressed air. Does the pump come apart to free the ball and clean the seat? It looks like the part the holds the ball and spring are peened to the pump body, otherwise I would try taking it apart and cleaning each. I have taken what I can apart and cleaned it thoroughly.

 

[trains]

Use some solvent, fresh fuel etc to clean it, lift the ball, and let it clack back down under spring tension, should break up any varnish test with blow suck from your mouth and some hose.
I cant remember, its been years since I had to clean and take the last one apart, sorry, but if its been peined over, then leave it alone, just clean it and test its sealing, put some oil in and push the piston in by hand, and you should be able to unseat the ball if there is no air in it.

 

[Mad Professor]

I just used my 009 pruning the orchard.

I took the pump apart a few years back. It was gunked up and needed cleaning. Bio-oil deteriorates, I quit using it.

The plunger does push the ball down on the piston downstroke (pressure in crankcase) and oil is pumped into the hose. On the piston upstroke (crankcase vacuum), the diaphragm moves the other way and oil is drawn into the pump through the filter. The ball check valve ensures a one-way flow of oil

You said the oil hose was intact without leaks? Could you missing the spring between the diaphragm and the cover plate? Also is that spring in the correct place, by the cover, not on the other side of diaphragm by the pump housing?

If you have cleaned the foam filter/new filter, the problem may be it needs to saturate with oil. You can do this before you install the pump but will be a little messy. Manual says it will saturate on it's own given a few minutes. Is the filter OEM or aftermarket? If AM maybe the foam is not saturating on it's own.

Last or first, thing to check, is clogged tank vent. Will it pump with the tank filler cap a little loose?

Note there are two styles of pump covers, the early one has more parts and an o-ring, the pumps work the same.

If early style check the o-ring.

 

[waverunner]

These guys would know the correct OG plunger length & operation answer. Give them some time to respond as they’re in Germany.

https://www.arboristsite.com/thread...1-012-and-oilpump-diaphragm-available.355414/

I had to get a new diaphragm kit from them to repair my pump. Stihl no longer make them. The do not include the plunger as they are no longer available as well. The position of the spring is important.

 

[stihltech]

I pull the brass nipple off and clean the whole pump. That will usually solve the problem.

 

[PhattyMatty]

What is the cotter key behind the bar stud and below the oil outlet connected to? My pump is clear, line is clear, check valve is good— I’m thinking my gaskets are misaligned

Edit — that cotter key is a split pin — that’s the vent hole. I’ve got no oil coming out of there either…

I’m assuming it’s safe to pull that in out as it’s not holding anything?

 

[Earthman58]

I've only just picked up on this thread but may be able to offer some help.

I make and sell the Plunger with Diaphragms (PD) and service kits including PD, Foam filters and gaskets on EBAY, being the simplest and most accessible means available to 09, 010, 011 and 012 users. My PD is unique, as I have redesigned it to enable the NBR diaphragm to be replaced at least once by re-using the core and plunger. The original PD was not designed to be dismantled, having press fit cups on either side of the core, these being damaged if you try to remove them.

In undergoing testing of the first prototype PDs it was obvious that plunger length is critical to correctly activate the non return valve.
I have sold sold many kits with both original spec gaskets and lazer cut paper alternatives obtained from the USA, I can confidently say that any slight difference in thickness does not impair the oiling capability. Incidentally, I have never had to dismantle an oil valve or replace the ball and spring; a good clean up of the core assembly seems to suffice. No NOS oiler cores (chamber and stem) are available from Stihl.

Having completely rebuilt 010, 011 and 012 models, other points of note are that the split pin used as a crude oil tank breather is often quite loose and can be replaced with a larger one without any problems arising with oil feed; it should certainly not be removed as Matty assumed. As the pump is at the base of the feed pipe - unlike more modern worm drive designs - there is always a lot of oil 'in transit' to freely drain after a cutting job. I find that the various purpose made oil trays all seem to fit this range and save constant oil spillage.

What nobody seems to have discovered is that the thing that really destroys these 4 models is the lack of new reed valves (RV). Two of my rebuilt machines suffered catastrophic failures where the valve disintegrated when the two Aluminium rivets holding the reed and back plate onto the plastic base sheared due to fatigue. I now advise that any old and cherished machine is either fitted with a rare NOS reed valve, or the rivets on any existing one are drilled out - with care not to melt the plastic due to heat - and stainless steel blind rivets used to rebuild it. Do not be tempted to buy a second hand RV, as these can not be considered safe after decades of use.

Finally to say that I have tested various Bio-Oils and found that the type in which latex was added caused my bars to lock solid in storage. I have used Rapeseed and Wheat based oils and find both acceptable but with a preference for the Rape, both having a natural adhesion to metal without significant additions.