DavidMSmith
ArboristSite Lurker
The original oil pump on my 136 died after about 10 years of occasional use - not bad going by all accounts. Up to that point, it used oil & the chain seem adequately lubricated - the saw leaked a bit of oil when left standing when not in use.
I replaced it with a non-OEM pump and infeed pipe from an eBay seller that I have used for other components - the vendor has a good feedback reputation and the pump looks OK. I removed the old pump and 2 part rubber infeed pipe/delivery channel housing, threw them away, and fitted the new pump inc the new 1 piece infeed pipe/delivery channel housing, cleaning everything thoroughly as I went along. Seemed OK on test - oil came out of the delivery channel. Put the bar on & left the saw to try the next day. Overnight, the chain oil leaked out of the full tank onto the bench!
Did some Google searching and found a recommendation to use a little liquid gasket to seal between the pump shaft and the rubber housing. Stripped it down, removed oil, applied liquid gasket sparingly at the interface between the shaft and the rubber housing, staying well away from the actual pump intake/outlet area. Left it to dry overnight. Pushed metal faceplate back on, applied bar nuts and temporary packing washers to simulate pressure from bar being in place, and with engine running, oil appeared at the outlet ready to go into the bar (if it had been in place).
Put the bar back on, tried out the saw for real, but it hardly used any oil and was soon running dry.
Stripped it down again, ensuring delivery holes were clear, re-assembled - same problem. By now the flow of oil from the pump was miniscule even with the metal faceplate removed.
The vendor kindly supplied another pump FOC. Fitted it without liquid gasket, replaced the metal plate and oil leaks out from the bottom of the faceplate lower down the saw but not thro' the (higher) delivery channel - not enough delivery pressure from the pump?
I do have concerns about the design of the 1 piece rubber moulding - the main body of the rubber moulding seems to stand ~ 2mm proud of the face of the rigid plastic housing uncompressed - the delivery channel stands another 1mm proud again. I would have expected the rubber housing to be flush with the rigid plastic, relying on the 1mm channel to form the seal. I wonder if under pressure of the faceplate and bar (when fitted), the whole housing is squashed together too much and seals off the oilways? It's as if its too thick? Unfortunately I threw away the old 2 part housing so can't do a comparison.
Anyone had any similar experiences? Should the rubber moulding stand ~ 2mm proud of the housing uncompressed? Any suggestions or tips gratefully received!
(This isn't an issue of a blocked oil feed hole in the bar as (a) it isn't blocked and (b) the problem is there without the bar fitted!)
Thanks in anticipation!
I replaced it with a non-OEM pump and infeed pipe from an eBay seller that I have used for other components - the vendor has a good feedback reputation and the pump looks OK. I removed the old pump and 2 part rubber infeed pipe/delivery channel housing, threw them away, and fitted the new pump inc the new 1 piece infeed pipe/delivery channel housing, cleaning everything thoroughly as I went along. Seemed OK on test - oil came out of the delivery channel. Put the bar on & left the saw to try the next day. Overnight, the chain oil leaked out of the full tank onto the bench!
Did some Google searching and found a recommendation to use a little liquid gasket to seal between the pump shaft and the rubber housing. Stripped it down, removed oil, applied liquid gasket sparingly at the interface between the shaft and the rubber housing, staying well away from the actual pump intake/outlet area. Left it to dry overnight. Pushed metal faceplate back on, applied bar nuts and temporary packing washers to simulate pressure from bar being in place, and with engine running, oil appeared at the outlet ready to go into the bar (if it had been in place).
Put the bar back on, tried out the saw for real, but it hardly used any oil and was soon running dry.
Stripped it down again, ensuring delivery holes were clear, re-assembled - same problem. By now the flow of oil from the pump was miniscule even with the metal faceplate removed.
The vendor kindly supplied another pump FOC. Fitted it without liquid gasket, replaced the metal plate and oil leaks out from the bottom of the faceplate lower down the saw but not thro' the (higher) delivery channel - not enough delivery pressure from the pump?
I do have concerns about the design of the 1 piece rubber moulding - the main body of the rubber moulding seems to stand ~ 2mm proud of the face of the rigid plastic housing uncompressed - the delivery channel stands another 1mm proud again. I would have expected the rubber housing to be flush with the rigid plastic, relying on the 1mm channel to form the seal. I wonder if under pressure of the faceplate and bar (when fitted), the whole housing is squashed together too much and seals off the oilways? It's as if its too thick? Unfortunately I threw away the old 2 part housing so can't do a comparison.
Anyone had any similar experiences? Should the rubber moulding stand ~ 2mm proud of the housing uncompressed? Any suggestions or tips gratefully received!
(This isn't an issue of a blocked oil feed hole in the bar as (a) it isn't blocked and (b) the problem is there without the bar fitted!)
Thanks in anticipation!
