Help, no water from my exhaust
- Thread starter Quandary
- Start date
Quandary
Well-Known Member
Latest update; got the pump out compete with gear wheel and tried to dismantle it. Tried drifting the shaft out (pity I had not seen Noelex very useful link above first) it did not want to move and I could not determine whether it comes out forward or backwards and I was not brave enough to whack it as the body looks quite fragile. Took it down to Jack in the local boatyard but when I told him the replacement cost, £300 he was equally reluctant to force it. The front seal was right down the shaft and out of the impeller housing, prised it up and out by levering with a screw driver then a cable tie through the vents behind the impeller. Seal looked fine and undamaged (engine has done less than 500 hours) Decided to reuse and assemble again because I did not want to risk damaging the pump by trying to remove the shaft when I was unsure if it came out the front or the back or both. In the meantime I may order a new front water seal if I can get one without having to spend £100+ on the pump service kit which includes bearings, oil seals etc. none of which should be worn yet. I will hopefully have it all back in place with the old water seal and ready to test tomorrow.
The leak did not seem to be there until I ran the engine with new impeller and the raw water system still blocked by small fragments of vane in the heat exchanger so my latest theory is that the pressure in the blocked system was high enough to blow the water seal out of its housing at the back of the impeller. There is nothing to stop it sliding along the shaft other than a thin O ring that is there to keep it away from the oil seal, but when it does it is visible at the vent holes so I should be able to monitor it for a while. So my lesson is that if you get a blocked heat exchanger, keep an eye on the raw water pump for water leaks. It would have been difficult but perhaps not impossible to push the seal back in to position with the pump body in still in place.
In the meantime, thanks all, I now know a bit more about raw water pumps than I did yesterday and if anyone who has dismantled the VP D1 30 (Shibura / Perkins) or similar raw water pump can recall how they persuaded the shaft out that would help me greatly.
The leak did not seem to be there until I ran the engine with new impeller and the raw water system still blocked by small fragments of vane in the heat exchanger so my latest theory is that the pressure in the blocked system was high enough to blow the water seal out of its housing at the back of the impeller. There is nothing to stop it sliding along the shaft other than a thin O ring that is there to keep it away from the oil seal, but when it does it is visible at the vent holes so I should be able to monitor it for a while. So my lesson is that if you get a blocked heat exchanger, keep an eye on the raw water pump for water leaks. It would have been difficult but perhaps not impossible to push the seal back in to position with the pump body in still in place.
In the meantime, thanks all, I now know a bit more about raw water pumps than I did yesterday and if anyone who has dismantled the VP D1 30 (Shibura / Perkins) or similar raw water pump can recall how they persuaded the shaft out that would help me greatly.
Stork_III
Well-Known Member
This link shows how to do it. Its essentially the same pump as VP, but VP use a gear drive not peg. Gear needs pulling off first. http://www.pbase.com/mainecruising/raw_water_pump
Martin_J
Well-Known Member
Can we assume it is a pump that looks like this.. with the big bevelled gear on the back...
http://www.marinepartseurope.com/en/volvo-penta-explodedview-7746500-26-8344.aspx
If so then the exploded diagram is here...
http://www.marinepartseurope.com/en/volvo-penta-explodedview-7746500-26-9344.aspx
This looks like the Johnson pump that is fitted to my MD2040.
Basically - to get that gear off you need to undo the nut.... but the only way of holding the shaft still is by gripping the gear! To do this I gripped the whole gear between two pieces of soft wood in a big vice. The nut then undid easily and the gear came off.
There is then an internal circlip (#9 in the diagram) that will need long straight nose internal circlip pliers to release. With the right pliers it will take 2 seconds to remove - with the wrong tools you will struggle. It is a big circlip. (Machine Mart or similar do good circlip pliers. Don't buy the thin ones with ends that clip on because they will bend!).
So... once the circlip is removed.. the shaft just pulls out (with bearings still on) away from the faceplate.
The seals are probably like these from simplybearings (but check for size)...
2 x 12x24x7mm R23 NBR Oil Seal (12x24x7_TC) approx £2.80
or a special double lip version
2 x 12x24x7 TCI / R23 Double Lip with Bi Directional Feature Viton Rubber Metric Rotary Shaft Oil Seal with Garter Spring (12x24x7_TCI_VI) = £11.80
New seals will push in.. one facing each way.. One is designed to keep water in the pump.. and the other is to keep oil in the engine. The air gap is so that if one seal leaks then water doesn't go into oil or vice versa.
You will find that once done you might in future be able to replace the water seal only from the impellor side.. It is possible but not so easy to check the shaft for wear.
Any questions just ask.. If it's not that pump then apologies in advance.
It's a seemingly impossible task to start with but it is manageable.
http://www.marinepartseurope.com/en/volvo-penta-explodedview-7746500-26-8344.aspx
If so then the exploded diagram is here...
http://www.marinepartseurope.com/en/volvo-penta-explodedview-7746500-26-9344.aspx
This looks like the Johnson pump that is fitted to my MD2040.
Basically - to get that gear off you need to undo the nut.... but the only way of holding the shaft still is by gripping the gear! To do this I gripped the whole gear between two pieces of soft wood in a big vice. The nut then undid easily and the gear came off.
There is then an internal circlip (#9 in the diagram) that will need long straight nose internal circlip pliers to release. With the right pliers it will take 2 seconds to remove - with the wrong tools you will struggle. It is a big circlip. (Machine Mart or similar do good circlip pliers. Don't buy the thin ones with ends that clip on because they will bend!).
So... once the circlip is removed.. the shaft just pulls out (with bearings still on) away from the faceplate.
The seals are probably like these from simplybearings (but check for size)...
2 x 12x24x7mm R23 NBR Oil Seal (12x24x7_TC) approx £2.80
or a special double lip version
2 x 12x24x7 TCI / R23 Double Lip with Bi Directional Feature Viton Rubber Metric Rotary Shaft Oil Seal with Garter Spring (12x24x7_TCI_VI) = £11.80
New seals will push in.. one facing each way.. One is designed to keep water in the pump.. and the other is to keep oil in the engine. The air gap is so that if one seal leaks then water doesn't go into oil or vice versa.
You will find that once done you might in future be able to replace the water seal only from the impellor side.. It is possible but not so easy to check the shaft for wear.
Any questions just ask.. If it's not that pump then apologies in advance.
It's a seemingly impossible task to start with but it is manageable.
Quandary
Well-Known Member
Sorted, for now at least? Sincere thanks to all those that helped me I appreciate the time and effort made to give me instructions and links. ( Martin, your instructions are spot on for this task)
Lessons learned
If you are doing a job for the first time, come on here for help first, as well as the usual Google search.
If you have a damaged impeller try to find all the bits before you run the engine again with the new one, I am convinced that the back pressure from the blockage in the heat exchanger blew the water seal out.
Boat and engine manufacturers will ensure that if a fixing can be placed awkwardly they will. I needed an assortment of spanners and sockets with extensions and articulated drives. You just got to be patient and keep your cool, that way you lose less skin.
Only thing I would add to Martins instructions: When putting the pump body back don't be tempted to assemble the impeller first, you need to be able to twist the shaft easily to get the gears to mesh cleanly.
Check everything else when you have access: I discovered that both my front engine mounting bolts were slightly loose and VP had thoughtfully placed one under the bracket for the throttle cable and the other tight under the alternator so that they have to come off to tighten them. I marked a fore and aft line on the head of each to give me an indicator if they get loose again.
The rig is the next job but it should be more accessible?
Lessons learned
If you are doing a job for the first time, come on here for help first, as well as the usual Google search.
If you have a damaged impeller try to find all the bits before you run the engine again with the new one, I am convinced that the back pressure from the blockage in the heat exchanger blew the water seal out.
Boat and engine manufacturers will ensure that if a fixing can be placed awkwardly they will. I needed an assortment of spanners and sockets with extensions and articulated drives. You just got to be patient and keep your cool, that way you lose less skin.
Only thing I would add to Martins instructions: When putting the pump body back don't be tempted to assemble the impeller first, you need to be able to twist the shaft easily to get the gears to mesh cleanly.
Check everything else when you have access: I discovered that both my front engine mounting bolts were slightly loose and VP had thoughtfully placed one under the bracket for the throttle cable and the other tight under the alternator so that they have to come off to tighten them. I marked a fore and aft line on the head of each to give me an indicator if they get loose again.
The rig is the next job but it should be more accessible?
Last edited:
Ceejay
Well-Known Member
Well done, good stuff