Raw water pump replacement questions

[LukeAvanti]

Hi all, another newbie here with a question or two. Recently bought a 1987 Catalina 30 Mk II. The raw water pump on the Universal M-25 engine has failed, I’ve procured a replacement. A few questions, along with a request for any additional guidance concerning the process for pulling old and installing new (I’m a bit of a newbie):
1. The engine is installed in a pretty tight space, and just getting the mounting bolts out looks to be a challenge, especially for an old (70) coot like me. Given the cost of replacement bolts, and the tight space, any hints about how to get those buggers out?
2. When installing the replacement pump (Oberdorfer N202M-15), should I use some grade of Loctite or similar to hold the bolts in place?
3. The gasket between pump and engine body: just clean and smooth, or use some sort of form-a-gasket or a thin film of oil?

 

[JoeWhite]

Good choice on oberdorfer. The gasket is included with the pump. Just install it. No treatment required. I do not have your version of engine, but removing bolts should be no problem.
Consider replacing the hoses aswell.
Haro.

 

[Ralph Johnstone]

especially for an old (70) coot like me

70 ? Don't kid yourself . I'm up the mast again for general inspection and a few repairs in April and only wish I was 70 again.

1. It's coming out with penetrating oil, a bit of waiting, and a judiciously placed breaker bar. Oh yes, and the foulest salty vocabulary you can come up with. It really helps.

2. No need for Loctite, just the required torque as stated in the engine manual. You're sure to find a copy somewhere in the Universal M-25 archives here.

3. Don't know Universal M-25 gaskets but @Stu Jackson will know.

I'm a Yanmar guy but I can imagine getting at your RW pump is as much fun as getting at the fuel lift pump (and everything else) on a Yanmar. Near impossible because of the position of the engine. The engine is stowed on board in a Nike running shoe box.



One thing I have learned over the years where you are stuck trying to attach anything to the block using bolts is to screw a few temporary studs into the block first to act as a guide. Below is the most disagreeable task imaginable on the rear of my engine .................. removing and inspecting the mixing elbow every few years:



The four studs are only temporary, hold the gasket, and the monster piece below slides into place along with its slippery little gasket:



............. the studs are then removed one at a time and replaced with the original bolts. I know, I know, I could leave in the studs in but I'm not happy until it's back to its original condition.

This has gone from one of the worst jobs of trying to handle everything with 1.25 hands to a one handed piece of cake.

 

[LukeAvanti]

Yikes! Thanks! Time to find a torque wrench I reckon...

 

[Ralph Johnstone]

Time to find a torque wrench I reckon...

Only for the purpose of differentiating between reefing the bloody hell out of a bolt or just being too limp-wristed. If you've wasted your youth working on cars, you won't have any problem judging the torque required for a given diameter of bolt. If you've never seen a wrench before, it'll give you a feel for it. Everything is steel in that diesel. No pokey little aluminum parts to overtorque (in which I specialize).

Go cheap from Amazon if you do get one. You're just looking for the feel of it.

 

[LukeAvanti]

thanks!

 

[Stu Jackson]

The gasket between pump and engine body: just clean and smooth, or use some sort of form-a-gasket or a thin film of oil?

Neither. You buy the gasket and install it.

With your engine, you might be interested in this:

Engines 101 - The BIGGEST & BEST collection of M25 Series Universal Engine Information on the Internet, plus some M35, too

Diesel Engine - c34.org


Look around the rest of the wiki, there are manuals, too.

 

[LukeAvanti]

Many thanks!