Stihl 084 oil pump

[RomuloTDI]

Hello everyone,

I'm new to the forum, I found it because I have a Stihl 084 and I'm looking for information about the oil pump because it doesn't work properly and since I can't find a new oil pump (at least at an acceptable price) I thought if it could be repair the one on my machine, I'll tell you, the oil flow is very poor and the auxiliary button for manual greasing doesn't work (the cable is fine, it's not broken but I don't notice that when you pull it it moves even a millimeter) so I I wanted to ask you if you know if my pump can be repaired and if it is very complicated, I have disassembled the pump and I have managed to disassemble it up to point number 17 (the spring that can be seen in the exploded view) but I have not been able to disassemble more, can anyone help me?? Thanks from Spain.

 

[jacob j.]

There's a tiny roll pin (#15) that needs pushed out so the control screw (#10) can be removed and the rest of the pump disassembled (if you haven't made it that far already). The number one issue with the 084 pumps is caramelized oil gumming up everything and then pump having poor flow due to being gummed up. Since these are big saws, it was very common for people to buy them, use them for a time, and put them in storage with oil still in the tank. That oil then starts turning into tar.

I've rebuilt many of these saws and almost always the pumps need cleaned out real good with straight gas or solvent. The manual oiler system is simply an override - it doesn't actively pump oil, it just holds the oiler at full output.

 

[Scotty Overkill]

There is a mod that can be done to the manual oiler plunger inside these 084 oil pumps that makes a HUGE difference in performance of the automatic oiler. The manual plunger, from the factory, is slightly too long and inhibits the automatic oiler from working to its potential. I did the mod to one of my 084s and it oils great now, even on longer bars. There is a thread on this mod somewhere here on OPE, I'll try to find it later when I have more time.

In a nutshell, you basically take a thousandth or two off of the manual oiler plunger (located inside the pump), it completely changes the game. I did the mod with a flap disc, steady hands and some patience in my basement workshop. I'll be doing the same mod to my other 084 next winter when I go over that saw.

 

[Scotty Overkill]

While you have thet pump apart, I highly recommend cleaning it (as mentioned) and also replacing the tiny worm gear seal in the pump housing. That seal can be problematic and a b*tch to figure out when looking for an air leak.

 

[Scotty Overkill]

@RomuloTDI, heres a link to the thread i was talking about earlier. Carefully read down through the whole thread to get an idea of what you can do to increase the oiling capabily of your 084. Not so much the "first" mod mentioned, it's the "second" mod later in the thread involving the forked manual oiler tang. I did it and it works great.


https://opeforum.com/threads/modifying-the-stihl-084-oil-pump-for-increased-flow.25547/

 

[Kiwioilboiler]

@markds2

 

[markds2]

@RomuloTDI, heres a link to the thread i was talking about earlier. Carefully read down through the whole thread to get an idea of what you can do to increase the oiling capabily of your 084. Not so much the "first" mod mentioned, it's the "second" mod later in the thread involving the forked manual oiler tang. I did it and it works great.


https://opeforum.com/threads/modifying-the-stihl-084-oil-pump-for-increased-flow.25547/

Thanks Scotty, yes, as you say, forget the first mod I tried (and thought was correct) and go straight to shortening that manual oiler 'fork'. It does wonders

 

[markds2]

Hello everyone,

I'm new to the forum, I found it because I have a Stihl 084 and I'm looking for information about the oil pump because it doesn't work properly and since I can't find a new oil pump (at least at an acceptable price) I thought if it could be repair the one on my machine, I'll tell you, the oil flow is very poor and the auxiliary button for manual greasing doesn't work (the cable is fine, it's not broken but I don't notice that when you pull it it moves even a millimeter) so I I wanted to ask you if you know if my pump can be repaired and if it is very complicated, I have disassembled the pump and I have managed to disassemble it up to point number 17 (the spring that can be seen in the exploded view) but I have not been able to disassemble more, can anyone help me?? Thanks from Spain.

The manual oiler 'fork' is item 16 on the exploded diagram above.

 

[RomuloTDI]

Hello,

Yes, I know, but I was referring to the fact that when I disassembled the oil pump I could only reach the spring, which is number 17, but I couldn't disassemble more, when disassembling the spring I tried to remove the rest by pulling the steel cable from the manual fork but nothing comes out, I don't know if I did something wrong or I have to remove something else, I wanted to know if the pump can be disassembled and how it is disassembled as well as if my oil pump has a solution because I can't find any and the which I find are very expensive.

Thank you.

A greeting from Spain.

 

[huskihl]

The only one I’ve had to clean out was from hardened oil inside the pump. It stripped the tang driver gear. So make certain your drive tang is turning the white plastic gear and riding in the clutch drum notch.

 

[RomuloTDI]

And how did you clean that oil? did you disassemble the pump internally? This machine, according to what the person who sold it to me told me, it spent many years standing still (I don't know in what conditions) and even the piston was stuck against the cylinder.

 

[huskihl]

And how did you clean that oil? did you disassemble the pump internally? This machine, according to what the person who sold it to me told me, it spent many years standing still (I don't know in what conditions) and even the piston was stuck against the cylinder.

Yeah, I took everything out and cleaned the inside of the oil pump with carburetor cleaner and a brush

 

[Scotty Overkill]

If you remove the manual plunger slide/cable assy from the pump housing, the slide simply slips off the cable end when you collapse the spring.

 

[RomuloTDI]

And as I remove the plunger slide/cable assy from the pump housing because I have not been able to move the piece that is behind the first spring that is there when starting to disassemble, as I indicated, I was not able to disassemble beyond number 17 which is The first spring, how do I disassemble the rest of the pieces (16, 2, 8 and 4)?

 

[RomuloTDI]

Perhaps part 16 is seized by dry oil or by the passing of the years? how can i unlock it?

 

[Wonkydonkey]

Perhaps part 16 is seized by dry oil or by the passing of the years? how can i unlock it?

If you have an ultrasonic cleaner? I’d use that with some type of solvent. Find a small container (put item in small container and use the solvent in it) then sit container in the water in the ultrasonic cleaner..

 

[RomuloTDI]

Hello, no, I don't have an ultrasonic machine, I had one but it didn't clean well at all, now I don't have it anymore, I'll ask tomorrow for some solvent that I can put on it or in which I can submerge the pump so I can clean it well and I'll disassemble it before all i can.

 

[huskihl]

Could put it in a pan with degreaser and let it simmer on the stove for a bit

 

[RomuloTDI]

But that could damage the internal parts of the pump, tomorrow I will buy a spray degreaser to see what they offer me and I will try

 

[Wonkydonkey]

But that could damage the internal parts of the pump, tomorrow I will buy a spray degreaser to see what they offer me and I will try

Yes that would be correct if you used the wrong type degreaser ( mag/alloy & alkaline degreasers aka sodium carbonate or hydroxide etc) but there are many others that could be good. Eg kerosene as it taske a lot of heat. Or you could loook at actone that actually evaporates at room temperature
Btw I recall some peeps use 50/50 actone and automatic transmission fluid a.k.a. steering fluid for unseizing pistons in cylinders . It may take a while but no heat required