Started to get ready for the season today, yes I know a little late. You try fitting in a job, little league etc. Anyway, I was able to get the transmission oil emptied and re-filled. I changed the Primary Racor and Secondary engine diesel filters in record time. Next was the Orberdofer Pump Impeller. Removed the 4 screws, the cover gasket, the snap ring came right off; the impeller will not move. I am afraid to remove the pump shaft, and I have watched mechanics do this job without taking the shaft out. What am I doing wrong? The engine is an 89 Universal M25XP. Please help.
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Oberdorfer N202M7 water pump?
They are all mover or less the same. I have one on my Atomic 4. The shaft and hence impeller can be difficult to get out after some time. The shaft should come out and is easy to re-seat. I say don't be afraid of using a vice grip (or other tool that might damage the old impeller) to twist and rock it until it comes loose. Of course it is nice to think that you can save the old one as a backup. My experiences with removing the shaft and impeller is that once it came out by hand and another time I had to use a small vice grip to get it out. If your pump is like mine and others I have seen on diesel engines there is a grease cup fitting that squirts a little grease into the sleeve that the shaft turns in. You are actually supposed to turn the cap, forcing a little grease in there about once a day before using the engine. You can either tighten the cap if there is any grease left in there or remove the cap and spray WD 40 (or your favorite lubricant) in there in the hopes of freeing things up. Persistence and swearing are mandatory when it does not come out easily. Good luck. If my link works, there is a picture of the Oberdorfer 202 pump about 1/2 way down the page.
They are all mover or less the same. I have one on my Atomic 4. The shaft and hence impeller can be difficult to get out after some time. The shaft should come out and is easy to re-seat. I say don't be afraid of using a vice grip (or other tool that might damage the old impeller) to twist and rock it until it comes loose. Of course it is nice to think that you can save the old one as a backup. My experiences with removing the shaft and impeller is that once it came out by hand and another time I had to use a small vice grip to get it out. If your pump is like mine and others I have seen on diesel engines there is a grease cup fitting that squirts a little grease into the sleeve that the shaft turns in. You are actually supposed to turn the cap, forcing a little grease in there about once a day before using the engine. You can either tighten the cap if there is any grease left in there or remove the cap and spray WD 40 (or your favorite lubricant) in there in the hopes of freeing things up. Persistence and swearing are mandatory when it does not come out easily. Good luck. If my link works, there is a picture of the Oberdorfer 202 pump about 1/2 way down the page.
Impeller
I appreciate the quick responses. The engine is not an Atomic, but a Universal M25XP. I did use a pair of vice-grips, while holding my thumb on the center of the pump shaft. I pulled as hard as I could, but the old impeller would not budge. I actually replaced the entire pump two years ago, so the current impeller is factory installed. I therfore assume it was installed correctly. If I remove the entire shaft to remove the impeller are there implications? Can I just re-insert the shaft or do I need to re-build the entire pump?
I appreciate the quick responses. The engine is not an Atomic, but a Universal M25XP. I did use a pair of vice-grips, while holding my thumb on the center of the pump shaft. I pulled as hard as I could, but the old impeller would not budge. I actually replaced the entire pump two years ago, so the current impeller is factory installed. I therfore assume it was installed correctly. If I remove the entire shaft to remove the impeller are there implications? Can I just re-insert the shaft or do I need to re-build the entire pump?
Do not worry Chief. The engine type matters not.
It is the same water pump that is used on both gas and diesel inboard engines. I would suggest you try to remove the shaft with the impeller using my suggestion of spraying WD 40 under the grease cup fitting and maybe even turning the engine over a few times to spread it around. It is no big deal to get the shaft back into place (especially if it is a recently replaced water pump unit). The end of the shaft has a slot or dado cut into it that fits over the driving mechanism. It should go back on easily once aligned properly. If your Universal diesel is like the one on my friends (similar engine but older) boat the water pump is facing aft and therefore very easy to work on (on my engine not so). You will be able to see the plate that fits into the slot and determine the angle which will mate with the shaft when you go to replace it. You can use a flashlight to look into the shaft without using a mirror as I have to do. If it is really stubborn you could try PB Blaster but be careful as I have heard that this is not good for rubber and there is a drive belt nearby, not to mention the old impeller. I think that if you can get the whole assembly (shaft & impeller) out then it will be easier to separate the two pieces. Re-insertion should not be a big deal. All it takes is patience and persistence (and cursing like a sailor as mentioned earlier). A counter intuitive approach might be to take a screw driver or other solid metal object and tap it with a hammer against the shaft (tapping it into the unit) to see if you can break whatever is binding it before trying to wrestle it out. If you have not been using the grease cap fitting on a regular basis then salt water has been getting in there and all kinds of corrosion build up can be expected between the different mating surfaces (the pump body is bronze or brass, the shaft is SS and I do not know what metal the driving tung is made of). One problem is that there is a pretty low tolerance as to how you can pull on the shaft. Side to side there is little clearance (with the danger of bending something), back or out is only one direction, so you could loosen the drive belt a little and try to spin it while pulling it out. With persistence you will get it out otherwise I will come down there and curse at it.
It is the same water pump that is used on both gas and diesel inboard engines. I would suggest you try to remove the shaft with the impeller using my suggestion of spraying WD 40 under the grease cup fitting and maybe even turning the engine over a few times to spread it around. It is no big deal to get the shaft back into place (especially if it is a recently replaced water pump unit). The end of the shaft has a slot or dado cut into it that fits over the driving mechanism. It should go back on easily once aligned properly. If your Universal diesel is like the one on my friends (similar engine but older) boat the water pump is facing aft and therefore very easy to work on (on my engine not so). You will be able to see the plate that fits into the slot and determine the angle which will mate with the shaft when you go to replace it. You can use a flashlight to look into the shaft without using a mirror as I have to do. If it is really stubborn you could try PB Blaster but be careful as I have heard that this is not good for rubber and there is a drive belt nearby, not to mention the old impeller. I think that if you can get the whole assembly (shaft & impeller) out then it will be easier to separate the two pieces. Re-insertion should not be a big deal. All it takes is patience and persistence (and cursing like a sailor as mentioned earlier). A counter intuitive approach might be to take a screw driver or other solid metal object and tap it with a hammer against the shaft (tapping it into the unit) to see if you can break whatever is binding it before trying to wrestle it out. If you have not been using the grease cap fitting on a regular basis then salt water has been getting in there and all kinds of corrosion build up can be expected between the different mating surfaces (the pump body is bronze or brass, the shaft is SS and I do not know what metal the driving tung is made of). One problem is that there is a pretty low tolerance as to how you can pull on the shaft. Side to side there is little clearance (with the danger of bending something), back or out is only one direction, so you could loosen the drive belt a little and try to spin it while pulling it out. With persistence you will get it out otherwise I will come down there and curse at it.
Impeller
One more time for the "deaf and dumb", if I cannot remove the impeller and god knows how I have tried. I used vice grips and pulled on the vanes of the old impeller and the part would not budge. Is it alright to just pull the entire unit out of the housing, remove the old impeller and re-insert the shaft assembly back into the motor? I am not going to upset anything within the motor? Thanks for all of your patience with me on this one. As I had stated, in the past I would have a mechanic change out the impeller and I always looked over his shoulder. It never looked complicated, in fact the hardest part always seemed to be getting the snap ring back into place. The old impeller just came right out.
One more time for the "deaf and dumb", if I cannot remove the impeller and god knows how I have tried. I used vice grips and pulled on the vanes of the old impeller and the part would not budge. Is it alright to just pull the entire unit out of the housing, remove the old impeller and re-insert the shaft assembly back into the motor? I am not going to upset anything within the motor? Thanks for all of your patience with me on this one. As I had stated, in the past I would have a mechanic change out the impeller and I always looked over his shoulder. It never looked complicated, in fact the hardest part always seemed to be getting the snap ring back into place. The old impeller just came right out.
One more time
IF you can remove the shaft/impeller assembly THEN you will not damage or upset any other part of your engine. This really is not rocket science as you have witnessed mechanics do this and I have done this twice, on two different engines. If you follow the link that I initially (2nd attempt) posted and follow to their 'pumps/parts' page you will see pictures of your pump and the shaft by itself (Product No. - CSOB_03_64 - Oberdorfer shaft). Take a look at it as it should help you visualize how it all fits together. There is a cutout, cutaway or slot at the back or inner end of the shaft that fits over the driving tung which is powered by your main engine belt (most likely). The other end is where the impeller goes and the snap ring fits over the shaft around a tiny groove. Unless you use a sledge hammer to remove the shaft you really can't damage anything else. If you can get the shaft/impeller out it is quite easy to replace. I still believe that the impeller and shaft mating surfaces have corroded enough to make it difficult to separate the 2 parts. Soaking the entire assembly with WD40 or Marvel Mystery Oil or even PB Blaster should help loosen up the corrosion. Good luck and let me know how it works out.
IF you can remove the shaft/impeller assembly THEN you will not damage or upset any other part of your engine. This really is not rocket science as you have witnessed mechanics do this and I have done this twice, on two different engines. If you follow the link that I initially (2nd attempt) posted and follow to their 'pumps/parts' page you will see pictures of your pump and the shaft by itself (Product No. - CSOB_03_64 - Oberdorfer shaft). Take a look at it as it should help you visualize how it all fits together. There is a cutout, cutaway or slot at the back or inner end of the shaft that fits over the driving tung which is powered by your main engine belt (most likely). The other end is where the impeller goes and the snap ring fits over the shaft around a tiny groove. Unless you use a sledge hammer to remove the shaft you really can't damage anything else. If you can get the shaft/impeller out it is quite easy to replace. I still believe that the impeller and shaft mating surfaces have corroded enough to make it difficult to separate the 2 parts. Soaking the entire assembly with WD40 or Marvel Mystery Oil or even PB Blaster should help loosen up the corrosion. Good luck and let me know how it works out.
Impeller is out
I gave it a few good wacks with a mallet and it came right out. Now the only issue is the gasket I have purchased for a few years does not fit. In fact there was no gasket to be found. As I had stated this pump was replaced two years ago. Previously I would change the impeller every year. I have the S/N of the pump and I am going to call Depco tomorrow to see if there is a different gasket or what they suggest to seal the cover plate. Thanks again for walking me through the procedure.
I gave it a few good wacks with a mallet and it came right out. Now the only issue is the gasket I have purchased for a few years does not fit. In fact there was no gasket to be found. As I had stated this pump was replaced two years ago. Previously I would change the impeller every year. I have the S/N of the pump and I am going to call Depco tomorrow to see if there is a different gasket or what they suggest to seal the cover plate. Thanks again for walking me through the procedure.
O-Ring
Maybe it has an O-ring in the housing to seal it. mine had the very large O-ring in the housing to seal the cover plate Nick
Maybe it has an O-ring in the housing to seal it. mine had the very large O-ring in the housing to seal the cover plate Nick
I believe the correct gasket is Product No. - CSOB_06_67
from the Moyer Marine website I linked you to before. They charge $3 for it (+ shipping) which means if you can find it elsewhere it will only cost about $1.50 - $2. One trick here is to only use the liquid gasket glue on the cover side only so (in theory) you wont have to replace the gasket the next time you take off the plate for impeller inspection/replacement. http://www.moyermarine.com/catalog.htm There must be someplace local around long beach as this water pump is quite common for boat engines. Glad you succeeded.
from the Moyer Marine website I linked you to before. They charge $3 for it (+ shipping) which means if you can find it elsewhere it will only cost about $1.50 - $2. One trick here is to only use the liquid gasket glue on the cover side only so (in theory) you wont have to replace the gasket the next time you take off the plate for impeller inspection/replacement. http://www.moyermarine.com/catalog.htm There must be someplace local around long beach as this water pump is quite common for boat engines. Glad you succeeded.
Gasket
I checked the Oberdorfer website and there is no gasket on the replacement pump that I had purchased. The pump is part# N2002M-15. They do use an O Ring, although I am not sure if that is enough to completly secure the cover plate. I sent an e mail to Oberdorfer yesterday, hopefully they respond with an answer. I will post their suggestion. Again thanks to all.
I checked the Oberdorfer website and there is no gasket on the replacement pump that I had purchased. The pump is part# N2002M-15. They do use an O Ring, although I am not sure if that is enough to completly secure the cover plate. I sent an e mail to Oberdorfer yesterday, hopefully they respond with an answer. I will post their suggestion. Again thanks to all.
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