Jump to content

85 720 Z24 water pump

Rickie B

Recommended Posts

  • Replies 8
  • Created
  • Last Reply

Top Posters In This Topic

Top Posters In This Topic

Not terribly difficult to do.


One or two of the bolts will not come out of the pump assembly. They stay in the assembly and will come with the new one.


Its worth it in my opinion to remove the radiator to gain the extra space. If you don't have an ac condenser then you can undo and redo the fan bolts very easily by going through the front of the truck.

  • Like 1
Link to comment

Remove the fan shroud, remove fan, remove fan belt, remove pump, clean up sealing surface with razor or scraper. Install new pump!


Lockleaf is right though.. removing radiator would give much more space but does add to the job.

Link to comment

Disconnect battery.


Take the rad out.


Take the fan off now. It has to be swapped anyway.


Loosen alternator belt adjustment to get the fan belt off.


There are 12mm and 10mm bolts to loosen and remove. (yes at least one 12mm long bolt comes out with the pump)


Have a good quality gasket ready. You do NOT need RTV sealer on it. It only squeezes from between the mating surfaces when tightened and ends up in the cooling system and eventually in the rad or heater, plugging it. This is what the gasket is for! Chevy owners don't know what gaskets are for.


Replace everything and top up rad. Belt tension is correct when you can push on the belt with your thumb very firmly between the pulleys and the belt moves about one belt width, If any coolant is left over, put it in the coolant recovery bottle. Next time the rad cools down it will siphon in and self fill. That's what it does. Warm engine check for leaks.



Always run a quality anti freeze/coolant mix.

Link to comment

I'd take the opportunity to replace the t'stat, rad hoses, and heater hoses as well. Use new clamps. Do a system flush and you should be cool for a long time.


And datzenmike makes a good point. Always run a proper mix of quality anti freeze and distilled water. I generally run the 50/50 mix at NAPA and have never had a problem with it.

Link to comment

Thanks guys for all the good advice,the water pump install went perfect, not one set back.As for the condition of the cooling system it is in perfect condition,it was all replaced when the motor was rebuilt about 20K miles ago.Looks like when they replaced the water pump at the motor rebuild, they used RTV or some kind of red gasket sealer,this actually deteriorated the gasket and started leaking.I replaced it withe a new Napa water pump and gasket and NO gasket sealer and used Napa 50/50 coolant ,test drove and all is good.Thanks again for all your help and advice it made the job so much easier.

Link to comment

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...

Important Information

By using this site, you agree to our Terms of Use.