Hi All,
I have a 2006 15hp Merc Serial no. 0p480631 Model No. 15E FS
Due to a low oil pressure problem that has been traced to a worn out oil pump I am trying to install a new oil pump however I am having problems getting the oil pump gasket to seal properly resulting in a (large) oil leak between the oil pump and cylinder head where they mate together.
The oil pump has a gasket and rubber O ring (2 in the drawing on this page http://www.perfprotech.com/store/as...tore/assembly/Oil-Pump-Camshaft,2726-140.aspx).
From my understanding of the diagrams in the service manual the gasket goes on first and the rubber o ring then goes round the central cylindrical part of the oil pump and gets slid down to sit on top of the gasket. The o ring then mates with a bevelled edge on the hole in the cylinder head that the oil pump goes into. With the o ring in place as described it prevents the oil pump tightening up enough to fully compress the gasket and form a good seal.
From what I can see the o ring appears to be too thick to fit into the groove created by the bevel and the side of the oil pump. It seems that it cannot be compressed into this groove and instead gets trapped between the cylinder head and pump preventing the pump tightening fully and therefore the gasket being compressed. Indeed without the o ring in place the pump visibly compresses much tighter but I have not run the engine without the o ring as it is obviously there for a purpose.<BR><BR>I have now tried this with 2 o rings, both genuine parts (part no. 25-825462) in case the first one was the wrong size or mishapen but have had the same problem with both.
If anyone can shed any light on the following I would be most greatful:
1. Am I putting this O ring on the correct place on the oil pump. From the diagrams it seems impossible that it could go elsewhere but it would be good to double check.
2. Is the o ring (part no. 25-825462) the correct one for this engine. As above from the parts diagrams and lists I have it seems that it is but again would like to double check
3. If anyone had a new o ring with part no 25-825462 to hand could you measure the thickness and diameter and let me know what they are.
4. Does anyone have access to the specification for this o ring in particular what thickness and diameter it should be.
5. Is it possible I have just been unlucky and got either a faulty part (to thick) or the wrong part in a package with the correct part no. on it twice in a row?
NB I am aware that with the tappets set the camshaft can prevent the oil pump seating properly but I have ruled this out by slackening all tappets and ensuring the rocker arms are free to move.
Many thanks for any advice or help you can provide
Gavin
I have a 2006 15hp Merc Serial no. 0p480631 Model No. 15E FS
Due to a low oil pressure problem that has been traced to a worn out oil pump I am trying to install a new oil pump however I am having problems getting the oil pump gasket to seal properly resulting in a (large) oil leak between the oil pump and cylinder head where they mate together.
The oil pump has a gasket and rubber O ring (2 in the drawing on this page http://www.perfprotech.com/store/as...tore/assembly/Oil-Pump-Camshaft,2726-140.aspx).
From my understanding of the diagrams in the service manual the gasket goes on first and the rubber o ring then goes round the central cylindrical part of the oil pump and gets slid down to sit on top of the gasket. The o ring then mates with a bevelled edge on the hole in the cylinder head that the oil pump goes into. With the o ring in place as described it prevents the oil pump tightening up enough to fully compress the gasket and form a good seal.
From what I can see the o ring appears to be too thick to fit into the groove created by the bevel and the side of the oil pump. It seems that it cannot be compressed into this groove and instead gets trapped between the cylinder head and pump preventing the pump tightening fully and therefore the gasket being compressed. Indeed without the o ring in place the pump visibly compresses much tighter but I have not run the engine without the o ring as it is obviously there for a purpose.<BR><BR>I have now tried this with 2 o rings, both genuine parts (part no. 25-825462) in case the first one was the wrong size or mishapen but have had the same problem with both.
If anyone can shed any light on the following I would be most greatful:
1. Am I putting this O ring on the correct place on the oil pump. From the diagrams it seems impossible that it could go elsewhere but it would be good to double check.
2. Is the o ring (part no. 25-825462) the correct one for this engine. As above from the parts diagrams and lists I have it seems that it is but again would like to double check
3. If anyone had a new o ring with part no 25-825462 to hand could you measure the thickness and diameter and let me know what they are.
4. Does anyone have access to the specification for this o ring in particular what thickness and diameter it should be.
5. Is it possible I have just been unlucky and got either a faulty part (to thick) or the wrong part in a package with the correct part no. on it twice in a row?
NB I am aware that with the tappets set the camshaft can prevent the oil pump seating properly but I have ruled this out by slackening all tappets and ensuring the rocker arms are free to move.
Many thanks for any advice or help you can provide
Gavin
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