Poulan 3400 oiler

[beard]

Howdy,
I have a Poulan 3400 that runs like a champ but doesn't oil. I've actually got 2 of these saws, one that I am using for parts. I've looked through the other threads on this oiler and I thought I had a handle on how they work. Here is what I have done so far . I've taken the oiler apart, including the manual oiler assembly. Soaked everything in mineral spirits. I replaced the quad ring with a snug o-ring and moved over the diaphragm from the donor saw since it didn't have any tears. The plunger moves freely. Replaced the pickup tube with a length of Tygon and the original filter . Once everything is put together, I can get the manual oiler to spritz AT fluid but not bar oil. It isn't a steady stream of AT though. I did oil everything inside the pump with bar oil thinking that would help displace any air . I have a service manual that talks about replacing the pump but doesn't show that actual service instructions for the pump. Does that exist ? Also, both diaphragms are stretched where the plunger sits. Is that suppose to be that way or is it the root of the problem. I understand from other posts that the diaphragm is no longer available and that some have cut new ones out of 1/64 Buna-n . I found 1 place with it and they cancelled by order because they were out of stock. I'd love to get this saw working again but it's becoming a bit of a pain... Thanks for any assistance

 

[hotshot]

Both diaphragms are stretched where the plunger sits? Only one diaphragm is used in the 3400 pumps, the 530019102 is just a backer gasket.

If it won’t work in either manual nor auto, the plunger bore is hand drilled out to clean & smooth, return spring is not rusted or broken, and the pickup tube/filter screen is clear, then it’s an issue with the check valves.

You need to test the two spring/ball check valves in the pump body, no instructions are given in the service manual.

Use your pressure/vac tester to check for blockage & operation. The inlet & outlet valves are both checked in reverse or backward flow, just like any standard dia pump or a carb fuel purger bulb set up.

Replacing the pump body with a used one is a lot easier than trying to clean out the midget sized valves, or to try to remove the “non-servicable” checks.

 

[beard]

By both diaphragms I mean the one out of the primary as well as the parts saw. Here is a pic of what it looks like. Should this be flat and only stretch on the impulse ? I’ll work on the check valves next. Thanks for the advise

 

[hotshot]

Yup, should be flat like these.

 

[beard]

Yup, should be flat like these.

View attachment 915062

Any idea where to get them or what material could be used besides 1/64 buna-n which seems to be impossible to get at the moment ?

 

[hotshot]

No, they’re obsolete now but do see them come across fleabay. I would head over to the Nick’s Poulan sticky thread & ask. #530024345

That roll material we used to make them from, a nylon woven nitrile, was from a group purchase in Canada made several years ago by a dozen or so AS members.

 

[beard]

No, they’re obsolete now but do see them come across fleabay. I would head over to the Nick’s Poulan sticky thread & ask. #530024345

That roll material we used to make them from, a nylon woven nitrile, was from a group purchase in Canada made several years ago by a dozen or so AS members.

Hotshot, you are genius! It was the check valve(s). Soaked the internals of the pump with carb cleaner and gave the inlets some pressure and then suction to confirm proper check and flow. Even with the slightly out of shape diaphragm it is pumping oil with the manual and auto . Thanks again for the assistance !

 

[hotshot]

Good job!

I looked & do have a spare 3400 oiler diaphragm already cut out, so send a PM (private message) if you want to buy it. You won’t like the price...lol

The remainder of my sheet was used up to make the smaller Super 25 oiler diaphragms to rebuild their pumps.

 

[dboyd351]

I was one of the people involved in the purchase of the oiler diaphragm material some years back and I think I still have some of it. I have not been on this site hardly at all for several years.
Send me an e-mail at [email protected] if you'd like.