B&S 2L Surface grinder oil pump help

[Froneck]

I decided to check if my grinder was getting lubricant so I removed the line from the oil pump. No oil being pumped. I removed the filter cover and removed the filter, probably was in there for 50 years. However without the filter it still will not pump oil. I do have the 2L shop manual but has little on pump operation. Anyone know how I can get it pumping so I can finish a job? Afterwards I'll disassemble the unit and fix it right!

 

[JST]

"How to get it pumping"? That is a rather open-ended question, as there are any number of reasons for it not to pump.

What kind of pump? Piston, I would assume, but....

If the piston is moving, but it will not pump, my first areas to check would be "is oil getting to the piston/cylinder assembly?" and "are the check valves working?".

After that, clogged lines, kinked lines, clogged Bijur orifice units, etc, etc.....

 

[Froneck]

Being a B&S 2L grinder it has the stock piston pump attached to the left side of the machine. Directions state how to adjust the stroke but nothing more! Has a list and pictures of component parts but not much detail. Pump and filter is submerged in oil.
From the pictures I can't determine how oil gets from the filter to the piston. I'm hoping someone familiar with the 2L grinder can give me direction.

 

[Froneck]

Anyone familiar with the B&S 2L surface grinder? Power feed model with Antifriction Bearing Spindle. Though in my case the spindle type is not important.

 

[Froneck]

does anyone one know how the piston pump should work in the 2L There seems to be only one check valve.

 

[JST]

does anyone one know how the piston pump should work in the 2L There seems to be only one check valve.

The other may just be in the Bijur regulators, which IIRC have check valves if for piston pump systems.

 

[Froneck]

As far as I know this oiler is not Bijur. Maybe made by Bijur that's possible. It's operated by a cam on the end of the table handwheel. I'll bring the book home and make photos of the parts page. Another page shows oil route. A line from the filter goes to the pump then a line drawn to various manifolds to distribute the oil to needed locations. An indicator is shown but have no idea where or what that is! A single line is drawn from the filter to the pump the another line from the pump to the manifolds. Both the pump and the filter in under oil! The entire unit is attached to the right side of the machine, back seem to be open so oil if free to flow into the housing with the pump and filter. Not sure how much oils but my guess is 5 gallons! Adjustment directions state the pump will maintain 70 psi oil pressure at at 50 strokes/min. One turn of the hand wheel will move the table 2" Table speed can be 19 or 31"/min. I'm using 19".

 

[Froneck]

Here is the parts and flow diagram from the manual. It's not exact in that I see errors but it's close enough.

 

[JST]

23-3214 looks like an orifice and maybe check valve. Could be just a tubing end fitting, I suppose.

 

[Froneck]

23-3214 is listed as a check valve. SPX1293 is listed as Pump Check Valve Steel Ball and 91-100 672 as Pump Check Valve Spring. It is odd the item 23-2314 is a check valve but at least 1.5" long It's attached to 23-3213 via a 1/8" pipe nipple about 1-1/4" long. The bottom has a Tee connection screwed in with the output tube attached to the 90° and pipe plug on the bottom. I assume that is 23-3404 output tube but is not the same on my unit. The output tube must be attached to the lower part of the "tank" since in enters the tank and is one of the tubes shown in the Adjustment photo on the left. What looks like a coupler on the top right of the outside of the tank is a plastic hose connection that brings the oil up to the table "V" and Flat way shown in the tube routing drawing.

 

[Froneck]

I looked again, The box for the pump is cast iron. Filter and pump section are separated as seen in the photo, Return oil goes into the Filter side. The check valve works, my guess in the oil from the filter side is transferred to the pump side after being filtered. The pump is completely submerged in oil.Removal of the check valve does nothing, I get no oil from the output as if the piston is not getting oil. Not a drop of oils comes out. The spring on 23-3221 (Pump Piston) holds the piston down, lever lifts it. I adjusted the adjustment nut to it's upper most position and lowest, lifted the pistol by hand and nothing came out. Today I plan to siphon the oil out, Looks like the pump assembly can be removed from the bottom.

 

[Froneck]

Drained the oil, was much lees than I thought, possibly 5 or 6 quarts. Noticed on the bottom underside of the reservoir part #23-3687 was being held in by 3 socket head cap screws. Removed the screws and the tubing. Pump came out of the bottom. Yes there are 2 check valves, should have seen that in the drawing since the two are shown and spring location reversed. Check valves work but can't get pump to operate. The small diameter of # 23-3221 is the piston, about 3/16" maybe 1/4" OD. # 23-3213 seems to be a one piece casting. I'll have to do some close inspection to determine how input and output access the cylinder, the 2 are located on center in one direction and 3/8" either side of center (about 3/4" CC) That is too wide to have drilled into the cylinder. I'll have to look for a plugged cross drilled hole. It's possible the input and output were drilled at an angle then straight bored for the check valves.
I guess it's possible the piston/cylinder wore so clearance is too much to pump oil. Might have to ream the cylinder and make a new piston. Then find a filter that will work!

 

[Froneck]

Removed the piston from the pump. It' mic"ed out as .188" and is hard (file will not touch it). Checked the cylinder, .188 gauge pin is sliding fit .189 was snug and when I put the mic on the pin (minus pin) it was slightly less by a tenth or 2. Would not go all the way in so clearance is less than .001". That should allow the piston in the cylinder to pump. I well cleaned the pump housing and can see in the check valve holes it was cross drilled but can't see the plug, was probably plugged then machined. Next I'll clean the reservoir and reassemble the unit. Now I have to find a filter that fits.
Before I install the pump I'll try to get it to work, I can't see why is don't!
Any suggestions?

 

[ratbldr427]

Piston pumps are pretty simple as you can see.The inlet check ball has to seat and seal when the piston goes down and unseat when the piston rises.Atmospheric pressure unseats the ball and hydraulic pressure ( created by the spring ) seats the ball. Check the ball seat carefully. The pump is self priming; submerged. You should be able to check it since it is out of the reservoir.Your piston clearances are ok but most pistons have some kind of elastic seal; o'ring or rubber cup.
Put the bottom of the pump in oil and pull the piston up, should fill with oil, release and should pump out the outlet if it does try it with the outlet plugged. The piston should hold pressure and not go down if it does then there are only two possibilities piston clearance is to high or the inlet check is leaking. One other rare but possibility is the cylinder is cracked. Not seen on low pressure systems like this but when it happens the crack is hard to see because it only opens under pressure. You will see it when you test.One other thing is the piston rod has to be leak proof where it is connected to the piston.
Kind of long winded for something so simple but if you have already checked, good, but that's all I've got!

 

[Froneck]

Cylinder/pump housing (23-3213) where the .118 bore for the piston (23-3221) is at least 1.500" in diameter (didn't mic. it). Only pressure applied to the piston is via the spring (6300) it keeps the piston down and cam lifts it. Spring is not very strong, I can lift the piston rod with my fingers but it's not weak either. I would assume the 70psi listed oil pressure is developed with the spring and .118 OD piston.
There is no way the cylinder could be cracked. Nothing is removable so there is no piston seal. In use the entire pump is submerged in clean oil, even the top of the piston rod that acts as a guide for the lower piston is submerged in oil. However when spring is totally compressed the piston is still partially in the cylinder.
I reassembled the pump, will attach the check valves and test the pump.

 

[ratbldr427]

That's how they all work. The reason the pump plunger doesn't go all the way , full stroke , may because the piston rod has some adjustment to control the stroke, most of that type do. The spring does control pressure and some are also adjustable. Real simple if you lift the piston all the way up and the cylinder is primed and you block the output the piston should not move, if it does then it is bypassing the piston. Un block the out put and oil will come out.
Don't see how a .188" piston is ever going to supply enough oil to the system. That's more likely some kind of valve connecting rod. The 1.5" diameter is what would be a normal piston size. Can't really tell from the parts picture.

 

[4GSR]

My 1980 version of the 2l grinder has a Bijur electric driven pump. I don't recall the CC's it pumps, maybe 5 to 7 cc's a minute. maybe more. It's a continuous flow pump. If it ever dies, there are hundreds of Asian built one's that one of them will take its place.

 

[Froneck]

Interesting 4GSR! Have any idea where I can by a small electric oil pump? What filter is in you grinder? As per the manual the pump develops 70psi by 50 strokes/minute. However the spring is what is lifted so it's the spring that will develop the volume of oil pumped. Doing the math my pump will do 23cc at 0psi. If I can't get the pump to work and electric pump will be great to get! However I will need a filter if my pumps works also if I have to replace the pump, so the filter in your grinder will be good to know! Actually I like the idea of an electric pump, oil is flowing even if the table is not moving!

 

[4GSR]

Mine has a small canister filter that Bijur used to sell that is mounted on the outside of the machine. It filters the oil before going out to the distribution blocks.

Here's a lubricator pump I'm thinking of.

110V 1L Dual Digital Display Automatic Electric Lubrication Pump Oiler NC Pump | eBay

1 x 1L lubrication Oil Pump. applies resistance systems. The Oil Pump has an oil level alarm system.

www.ebay.com

Many others to choose from on eBay. Take your pick.

lubrication oiler in Lubrication Pumps for sale | eBay

www.ebay.com

 

[Froneck]

Thanks 4GSR but I was thinking of just a pomp. I guess I can mout the complete unit on the side of the cast iron reservoir. Drill a hole an inch below the overflow notch and connect a hose to the filler opening of the ebay pump assembly. I did find a metal screen filter similar to McMaster # 44275K18. Might alter to make it fit.
E-bay unit is cheap enough I'm going to order one.