LS Water Pump -16 Fitting Tech

[1TONTJ]

Reading this thread: http://www.hardlinecrawlers.com/forums/index.php?topic=50670.0 inspired me to do a little tech thread on an alternate method of converting the LS water pump inlet to a -16 fitting. I too have had trouble installing the popular push in style aluminum fittings and have had to deal with splitting the aluminum housing. Here's what I came up with.

First, you need to pick up a 1" male O-ring face seal to male 1" JIC fitting at your local hydraulic store or online. The threads on this particular fitting are 1.44" o.d. which is different than other sizes.





Next, you will need a 1-7/16 x 12 tpi tap. I found a cheap one on eBay.



Put your water pump into a vise with soft jaw inserts to hold it while you remove the steel water neck. I use a pair of Vise Grips and a hammer to tap it out of the housing.





The i.d. of the housing on this particular water pump is 1.2955".



The i.d. needs to be bored to 1.35" for the tapping process. Now, the proper way to do this would be to have a machinist do it but I'm writing this for us common folk. I first used a brake cylinder hone to take off the majority of the material. I went through two sets of stones during this process.



With the bulk of the material removed, I used a 1-1/2" flap wheel in my drill to finish it off to 1.35". The wheel is flexible enough to be squeezed into the housing. (My electric die grinder didn't have enough power to turn the flap wheel in the housing)





Finally, tap the housing. Go slow, use plenty of lubricant and pay attention to your alignment





Voila!







I recommend adding some RTV or thread sealant before final installation.


Again, this is probably not the best way to thread the housing and I have yet to test it for leaks. This tech is aimed at the common wheeler who likes to do stuff himself in his own garage. I guess if it doesn't work you could always buy the press in fitting and just weld it on. laughing1


I'm crossing my fingers that it works. If not, I owe SHAWNEECRAWLER a new water pump! laughing1

 

[1tonrenegade]

Good ideal. You could put an o-ring on that fitting if sealant don't work

 

[RustyC]

The fitting you used is an o ring face but is also machined for a second o ring just under the hex. Fittings with o rings under the hex a called o ring boss. I agree an o ring added under the hex would be best. Well done good tech.

 

[TBItoy]

Re:

Curious as to why you did not use an o ring boss or npt fitting?

 

[1TONTJ]

Re:

Curious as to why you did not use an o ring boss or npt fitting?

Because the male thread o.d. on both the o-ring boss and npt fittings is only 1-5/16", which is too small. The o-ring face threads are 1-7/16". Also, using an NPT fitting would probably split the aluminum housing once tightened.

 

[TBItoy]

Re:

Because the male thread o.d. on both the o-ring boss and npt fittings is only 1-5/16", which is too small. The o-ring face threads are 1-7/16". Also, using an NPT fitting would probably split the aluminum housing once tightened.

Good to know.

And yeah big npt fittings can be a pain in the ass

 

[Beerj]

Nice work. Seems like it would be a great option.

 

[tonybolton]

Re:

Will someone educate me as to why we need to go through this whole process instead of just using a hose and hose clamp on the stock pump?

From an amateur point of view this looks like a lot of work where normally a slip on hose and $2 hose clamp would work.

 

[Eddyj]

Hose clamps on a LS??!?!? That would be like using square tube for links...

 

[tonybolton]

Re:

Well...they work....right?

 

[TBItoy]

Re: Re:

Will someone educate me as to why we need to go through this whole process instead of just using a hose and hose clamp on the stock pump?

From an amateur point of view this looks like a lot of work where normally a slip on hose and $2 hose clamp would work.

Cause giant AN fittings are baller as dammit yo.

 

[Beerj]

Will someone educate me as to why we need to go through this whole process instead of just using a hose and hose clamp on the stock pump?

From an amateur point of view this looks like a lot of work where normally a slip on hose and $2 hose clamp would work.

I look at it from a safety standpoint. On my rig at least, there isn't a whole lot separating you from the engine compartment And even less separating you from the radiator. Sure, AN fittings can fail but I see it less likely than conventional hose clamps and would like to avoid a near boiling shower of coolant.


Plus they're baller

 

[pholmann]

My reason was two part. One part aesthetic and one part being proactive against any leakage. If you have any leakage with a rear radiator system, it causes an air bubble that causes overheating and is a bitch to get out.

 

[hink311]

Re:

Will someone educate me as to why we need to go through this whole process instead of just using a hose and hose clamp on the stock pump?

From an amateur point of view this looks like a lot of work where normally a slip on hose and $2 hose clamp would work.

. You must not pay attention to his attention to detail

 

[tonybolton]

Re:

Yea....I don't try to reinvent the wheel.

 

[patooyee]

Re:

Yea....I don't try to reinvent the wheel.

AN fittings actually vastly reduce the size of the coolant hose, too. ID of a -16 fitting is less than an inch. ID of radiator hose is 1.25" - 1.5". Ask anyone, I am an AN junkie. I actually carry a separate toolbox on my trailer with JUST AN plumbing. I am a mobile hydraulics store. As much as I want to, coolant is not generally somewhere I use it though.

 

[Beerj]

That's why I went with -20, 1.075 on the id.

 

[pholmann]

Me too. All of mine are -20

 

[slytowncrawler2]

Sooooooo will 16 keep mine cool or do I need the 20???????? I'm gettin ready to do mine an am completely ignorant as to wich one I need....... I'd like to run AN stuff for ease of routing an do away with damn muffler pipe headed to the back.... Along with hose pointed at the back of my head :/

 

[pholmann]

overkill!! Id go 20 I did.