rebuilding a delaval 76 vac pump

[twobears1224]

has anybody ever rebuilt a delaval 76 vacuume pump?? i have one i bought at a farm auction.i,ve seen alot of pumps at auctions really cheap and i,am thinking about picking them up if the price is right and the case seems to be ok..no cracks,ect..ofcourse i won,t know what they look like on the inside until i pull them apart.
i see parts online sells rebuilt pumps and they talk about what they do to them..ofcourse new bearings,a seal and vanes and they machine the inside.

delbert

[Haynes Forest Products]

TwoBears I have taken them apart. But they looked good so back they went. I find that if you spin them by hand they will make noticeable vacuum. If the vanes are fine and it had oil in it I would think its good. I was at a dairy supply and repair place and they had a pallet full of vacuum pumps of all types and they said that they all go in and get rebuilt come back as new specs. New bearings, gaskets, vanes, seals, machining and paint.

[brookledge]

I have taken apart vane style vac. pumps many times and have cleaned the vanes. many times they can get gummed up and stick. So when it is turned on either you get no vac. or it sounds like a engine running with one less cylinder. I have also taken the bearings and seals to a local automotive store and gotten them replaced.
Good luck
Keith

[3rdgen.maple]

Never done a delaval pump but I do gast vane pumps monthly. A couple things I can recomend. Do it right once and i will last you many years. Get a cylinder honing tool from an auto store that goes on your drill. Hone out the cylindre wall lightly to get the glazing of the walls. If you see any mild scoring on the cylinder hone it till its gone. This will help make for better vac transfer and aid in the longevity of your vanes. Flush the cylinder out well to get her clean and all particles out of the system. I would also replace your bearings regardless if they feel good or not. You have it apart now why go back after one season and do it then when they fail. Inspect the vanes and if there is mild scoring on them a fine peice of sand paper on a flat surface and lightly smooth them out. If they are pretty worn down or have excessive grooving from the contact of the slot they fit in replace them. They are not cheap. Slap it all together and let her run for an hour under no load to let the vanes settle back in nicely. Give her a nice shiny new paint job and enjoy your pump.

[Maple Ridge Enterprises]

I rebuilt a deleval 78 last season... Not so good of results but maybe someone can shed some light on this.. I replaced all the vanes, seals and bearings, used some very fine emery to get the gummed up stuff out. Checked all oil lines and they all worked fine. Pulled 28 inches of vac the first six hours and then went down from there. I was so upset I quit sugaring about three days early. The repair parts were about $250.00 and I was on a budget for the season. I have since bought another repair kit and plan on rebuilding this beast again but need some advice. Where did I go wrong.. HELP PLEASE ... Thanks Bill

[maplecrest]

were you reclaiming the oil? those pumps are not made to pull 28 inches of vac!! you will do 22 inches on a cool day but as the season goes on and it gets warmer the pump is hard to cool. more like 18 to 20 inches. an oil reclaimer is a must! a auto transmission cooler between the reclaimer and the pump will help cool the oil. a 5/16 line of water running onto pump head will cool it. but heat is your killer. running diesel fuel thru it will clean the gum off the vanes.

[Haynes Forest Products]

I run my Masport all day long with oil flood and I dont use a vacuum regulator for cool air into the pump. Have you ever seen a VW engine blown and injected so Yea you can get a dairy pump up to 26 all day long even with end of season temps.