Water Pump Lower Bolt Removal

[Bruce A]

Hi,

This is my first post so I hope the format is correct. I have an Islander 34 with the original Atomic 4. The engine runs great and we have had no complaints until last week. I noticed a steady drip (almost a run) coming from the upper hole of the water pump so my plan was to remove the pump and replace it. The top water pump bolt is no problem to reach and it is in reasonably good shape. However, the bottom bolt, which I assume would take an 9/16" wrench like the top bolt, is deteriorated to the point where a 3/8" to 7/16" will slip over the head which is almost round.

First, I would like to know how serious the leak is in terms of whether or not water can get into the oil through the defective pump seal? and second, does anyone have any suggestions on how to get the bottom bolt out given the very limited space available in the engine compartment?

Also, is it possible to remove the transmission housing with the engine still in the boat and thus allow for removal of the bottom bolt and pump on the bench. If the transmission housing can be taken out while in the boat how do you reseal it since the pan gasket would most likely be damaged?

Any thoughts would be greatly appreciated.

Thanks,

Bruce

[Kurt]

I'll take a stab at this one and hopefully we'll get some ideas for you, Bruce. I have dealt with water pump seal leaks before. When you say "the upper hole of the water pump" I'm assuming you are referring to the 'weep hole' on the body of the pump which can be seen from both above and below the pump. If you see water coming from here, you shouldn't have a problem with water getting into your oil. It is my understanding that one of the reasons for having both a water and an oil seal in the pump is to prevent water from mixing with oil and vice versa. You do want to fix this seal as soon as possible as a water leak in this area can cause significant corrosion in this region of the engine and, as in my case, a neglected leak caused some nice rust damage to an engine mount. Replacing the seal is not that difficult - get a pump rebuild kit from Moyer (or just a couple of seals) and follow the directions. If one seal failed, you should replace both seals and observe the condition of the pump shaft. Once you have everything apart, you might as well replace any suspect parts or those that are towards the end of their lifespan.

As far as the lower water pump bolt with the stripped head, that may represent an exercise in creativity. I think you are oversteering by thinking in terms of anything other than removing the bolt. Dismantling other parts of the engine should not be necessary. Auto part stores sell sockets that can fit any size or condition bolt head (they have a bunch of metal fingers in them that form around whatever head you have) - you might want to try one of those. Vice grips are worth a try. Spray the bolt with penetrating oil (like PB Blaster) and let soak for a while before trying to remove it if it hasn't been removed in a while, looks rusty, etc. If nothing works, a better last resort than removing large unrelated engine components would be to grind the head off and drill the bolt out.

[forcenine]

Don also sells an extender for that difficult nut although the one I bought wasn't serviceable since I still didn't have sufficient room to even get it in place. I managed to get an open ended combo wrench on it at an angle and do incremental turns until fingers and closed eyes finished it!

[Bruce A]

Thanks Kurt,

I found a spiral fluted socket call a "bolt out" that may work to remove the bolt.

It looks like the bottom weep hole may have been leaking for awhile before the top hole started to leak and as a result there is some rust buildup on the rear starboard engine mount bolt as you experienced.

Thanks for the advice, I will attempt to remove the bolt tomorrow and let you know the results.

Bruce

[Don Moyer]

Bruce,

As long as you have access to all the bolts along the front of the aft housing, the four along each side, the six retaining bolts for the rear flange and can remove the output coupling, you should be able to remove the aft housing. When removal of the aft housing is necessary to replace the reversing gear, new pieces of oil pan gasket are used to replace the section that will no doubt be damaged in removing the aft housing.

My biggest concern is that the retaining bolts for the aft housing below the water pump usually meet the same fate as the lower retaining bolt of the water pump itself.

Don

[Bruce A]

Thanks very much for the support. Don, thanks for the words on the transmission housing removal but I will not have to remove the housing (at least not now) as I GOT THE LOWER WATER PUMP BOLT OUT!! It was very difficult as there was basically no head just a round shoulder about 1/16" high that was just enough to prevent removal of the pump (by-the-way, the top bolt came right out with very light wrench torque). I sprayed the bottom bolt with PB Blaster, let soak, then tapped the "bolt out" fluted socket onto this little stub of a bolt head. The "bolt out" gadget could not get enough purchase to turn the bolt but repeated tapping, reapplying the "bolt out" socket and wiggling the pump housing eventually loosened the bolt and I could actually remove it with my fingers near the end of the process.

The pump is the original Sherwood 6 screw model that was used in 1969 when the engine was manufactured. It has a worn shaft, that is, there are two distinct grooves where the two seals have been rubbing on the shaft. The seal at the water end of the system is completely shot and the oil seal is marginal.

A question for Kurt and Don, I noticed in your earlier communications that Kurt had repetitive leak problems with pumps due to a faulty accessory drive. Is there a way check the drive while in place on the engine to hopefully ensure that one will not have the problems that Kurt had?

Last issue---what to do about this old pump. I would guess that if available a new shaft for the Sherwood pump may be hard to find and probably expensive so it may not be practical to rebuild my old pump. Is the MMI pump a drop in replacement or would I have to try to find a new or rebuilt Sherwood unit? Also, is the MMI pump assembled with anti-seize compund on the four cover plate thumb screws or is this something that one should add before installation.

This is really a great forum for resolving these Atomic 4 issues.

Thanks again,

Bruce

[Kurt]

Congratulations, Bruce - a little effort and creativity worked out. MMI pump is an excellent pump and can be installed on your motor. The only thing you may need to deal with is the 'in' and 'out' holes on the pump. It will be obvious if you have to use different brass fittings in these holes - available at your local plumbing store - no big deal if needed. Nothing else is needed for the pump - just install and it's ready for use.

I don't think you need to worry about your assessory drive. My issue was very rare. I just posted that experience in case anyone else out there is stumped as to repeated water pump seal failures. It sounds like your pump is just old. If your assessory drive is bad, you will hear unwanted noise coming from the drive when the engine is running - usually a low grinding type sound. By your description of the pump condition and age, you have found your smoking gun. If, however, you are concerned for some reason about your assessory and it is making noise, I believe the way to check it is to take a short length of 2x4 and press against the pulley while the engine is running. If the unwanted noise goes away with some side pressure on the pulley, then your assessory drive bearings may be worn. Again, noises in this area should make any concerns obvious and these drives are pretty robust units and not commonly problematic.