1994 Mazda 626 4CYL Water Pump Replacement

Hi Guys

I know this is a Miata forum but its also the only ram. forum for mazda. I'd just like to know what is involved in replacing the waterpump on the above car?

I'd like to do it myself and save money on labor if its not too tricky and I can do it with the typical do-it-yourselfer tools.

What are the steps involved?

Thanks,

Danish

Reply to
Danish
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I think a good number of the posters here have some experience doing various levels of automobile maintenance. So when you read about someone replacing this or that, it probably should not be considered a "professional" statement, but most of these folks have turned a wrench or two.

Mazda, like other vendors, uses twin cam engines where the cams are driven by a timing belt. The timing belt spins a couple of other things besides the cams, one of those is the water pump. That's why you will often see timing belt changes accompanied by water pump replacement. Conversely, if you are going to change the water pump, you should consider changing out the timing belt at the same time, unless it is reasonably new (which, if it is, suggests that the water pump should have been changed at the same time). Other replacement components are the tensioner and idler pulley.

If, in reading this so far, you haven't a clue as to what I am saying, then you should consider a different level of involvement vs. the one you described. My suggestion would be to enlist the help of a automotively minded friend who can assist and guide you through the steps to get this done while teaching you the fundamentals of auto repair. A decent manual is typically required, but there are some details that you will have to figure out for yourself, especially if you rely on something like a Haynes.

In essence, it is merely a series of steps that must be taken in order to accomplish the job. It is fair to warn you that these steps require a certain level of knowledge and skill. It's not at all rocket science, but can be daunting for a beginner. We all have to begin somewhere, however.

I do stuff like this because, as you point out, it saves money. But the other reason, probably more compelling for me, is that I simply don't trust the rank and file auto mechanics out there to do the job correctly. If I do it, I know it will be done right; that's worth something to me. If you have a mechanic you can trust (and there are certainly good ones to be found), then it's a matter of money and the inconvenience of drop off, pick up, rental car, etc.

Ken

Reply to
KWS

Thanks for the posting.......i've understood everything you've said in your post. Can you give me a brief description of whats needs to be done? Will the block have to be lifted?

Reply to
Danish

OK. Briefly:

I can't speak for your car, but I'll talk about the 1997 Protégé I did earlier in the year.

I used a Chilton manual that was generally helpful, but attempts to be all things to all models and can be confusing. You have to read it carefully and, even then, there will still be some surprises.

First step was to drain the coolant. Then, jack up the car, remove the passenger (USA) side tire land the chassis on a jack stand. This gives access to the front of the (transverse) engine. On the Protégé, it was also helpful to remove the headlight assembly and other plastic bits for access reasons as well.

Next came the removal of accessory belts (alternator, etc) and the water pump pulley. A hint here is to loosen the water pump pulley bolts before removing the belt.

Once the belts and pulley were removed, you have access to the timing belt covers on the front of the engine.

On the Mazdas I have done, the cam cover (valve cover) has to come off to access the cam pulley (or pulleys...depending on the design). This is a good time to replace the spark plugs, spark plug wires and the cover gasket. Note that Mazda requires a blob of RTV on certain areas when installing the new gasket. I also suggest stuffing rags into the spark plug holes so nothing falls in there while you are doing this work.

Remove the belt covers and, using an appropriate socket, turn the crankshaft until the crank pulley mark and timing marks are aligned per the manual instructions. This is, of course, a lot easier with the plugs removed.

Mark the old belt, crank and cam pulley(s) with indelible marker at reference points on the timing belt teeth and pulley. This is important as you will transfer these marks to the new belt and re-install the new belt exactly to these marks.

Loosen the tensioner pulley, remove the tensioner spring, push the pulley out of the way and temporarily lock it in place. Depending on the design, you may want to remove the pulley if it is associated with the water pump assembly. It may help for easier removal of the belt. Depending on the design of the engine, you may have to remove the crank pulley. If you do, it is helpful to know if there is any specific key orientation and the correct mounting torque when re-installing the pulley. On the Protégé, I had to put a wood block under the engine to support it while unbolting the top engine mount (to allow removal and replacement of the timing belt). The Chilton manual did clearly state that this was required for another engine but failed to do so for mine. It wasn't such a big deal, but highlights that these enthusiast manuals can skimp on details.

Remove the belt and, when convenient, carefully transfer the marks on the belt to the new one. Remove and replace the water pump using appropriate gaskets and mounting torque. Put any idler pulley, tensioner spring and tensioner pulley back on the engine block, install the new belt and don't forget to rebolt the engine mount. Before setting the tensioner, turn the crank pulley two revolutions and ensure the timing marks on the crank and cam(s) align properly. Note that the marks you put on the belt will no longer align. This is OK. There is a point to which you set the crankshaft before letting the tensioner spring tighten; the manual probably states this. On the Mazda engines I did, it was about 5/6 of the second rotation, before TDC of the #1 cylinder.

Clamp down the tensioner pulley to the specified torque, put all the covers, belts, hoses, sparkplugs, wheels, etc back on. Put in the appropriate amount of coolant, check everything one more time and fire it up.

As you requested, Danish, this is the Reader's Digest version of the job. I suggest you need a bit more than this general information to do this properly and, of course, any outcome good or not so good is up to you. Good luck; let us know how you made out.

Ken

Reply to
KWS

I think the main problem may be that cars are continuously changed from one year to the next, and the manual publishers seem to have no good way of tracking those changes. Certainly Haynes confuses the various differences between different generation Miatas.

Leon

Reply to
Leon van Dommelen

Yea. Hence my advice that one must be "mechanically minded well" to deal with this.

Ken

Reply to
KWS

This will give you every detail of the job. I've just done it - I would say that you need to be fairly confident / experienced as an amateur spanner wielder and you'll need a weekend.

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Reply to
Morien Morgan

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