Thread sealant is what you want. Search "water pump" and search by recent threads for more info. Now would be a great time to install a new cap and rotor on your optispark if you can afford it. And loctite the rotor screws.

 

Thank you Sherlock9c1, I will look into that. Any pitfalls to working on the OptI Spark? What is your preference to these parts and where to shop?

 

There's a 4 part series on YouTube by goldmaster on changing the water pump and seals

I was able to follow it almost step by step

 

I'd be tempted to let opti be if car is running well. One can always revisit this later if need be.

 

The lower, DS, WP bolt is the only one that needs "thread sealer" (read NOT RTV)

There is a 50/50 chance the WP drive seal will leak after a WP swap IF you do not replace that seal as removing the spline, ESPECIALLY IF IT IS HARD COMING OFF, can disturb that seal causing it to leak. IMHO replace the WP drive seal BUT use some form of tool (buy the $20 ebay one) to install it. NEVER grease that seal (not sure if video shown says so but IIRC one did)

If the WP was weeping from rear there is a 100% chance there is some contamination inside OPTI. Just remove C&R and carefully clean it with Q tips. Use dialectic grease, skim coat, on the large O ring for Cap.

The mechanical WP's are a crap roll on being good relative to leaking quickly from weep hole. For cars that I have mechanical WP, I found NAPA new ones lasted longer. For me nothing has lasted 22 years like my Meziere EWP. YMMV

 

There is a splined sleeve that connects between the H2Opump and the cam drive.
When you take the H2Opump off, it might stay on the engine.
If it stays on the pump - or you take it off the engine to put it on the H2Opump - don't flip it!
Even if you decide to replace the O-rings on it, maintain its original orientation.

 

Do yourself a favor and dump the mechanical pump. None of them last long these days and my last failed one took the pump drive with it. Installed an electric pump and couldn't be happier. Car runs much cooler and outside of very hot days (lots of those in central Florida) the gauge never hits the mid mark.

 

Do yourself a favor and dump the mechanical pump.
None of them last long these days and my last failed one took the pump drive with it.
Installed an electric pump and couldn't be happier.
Car runs much cooler and outside of very hot days (lots of those in central Florida) the gauge never hits the mid mark.

Replaced my mech H2Opump 3x in 2 years.
(schmuckanic flipped the gottdamnt spline sleeve the wrong way).
Made it very clear that there was something wrong INSIDE the front cover.
Cost to fix H2Opump drive mechanism inside front cover: $800 (back in the EARLY noughties).
Even if paid $1000 to use another mech H2Opump it'd not've lasted long enough to be worth it.
Cost to convert to a Meziere WP118HD, with electrical rewiring, installed:
about $250 (back in the early noughties).
(The mere WP118 is easier to acquire, but inferior to the WP118HD.)
Lasted over 10 years / 125,000 miles of me driving like a meth'd up cabbie.

If your H2Opump is all good'n'tight now, can't hurt to find another leakfree mech H2Opump to convert for the future.

 

Electrics outlast mechanicals more so these days. They have advantages which are significant.
They don't leak ,quick/easy to swap out ,water pump drive seals last practically forever ,etc....

 

Not speaking ill of them as I had one but am I the only person to have Meziere leak ?
**** happens but the fight about the warrenty is still in memory.
Meziere wanted to go by manufacturer date not purchase date. Great, mine must have been languishing out of reach on the Summit shelf for more than a year and a half !!

What exactly is the difference on the two ends of the coupler? I do remember a reference line.

 

I did it my self in driveway too...it turned out GREAT ?

leaking from the weep hole.....8-(

Finally got my turn i guess... i started having Power steering issues and then saw the green stuff leaking...got the car in the air this morning and found the weep hole wet, and green stuff on the bottom of the crank pully, so the belt is getting a bath too... just wanna make sure i am not...

www.impalassforum.com

good Luck.
-ALF out....

 

My info. on coupler is the end with the line goes towards the motor. My only guess is so it continues to spin in the same dirrection so wear pattrens don't "argue" ,so to speak...

 

Think ,wear wise , reversing it would not change the sides of tooth wear.
Coupler is driven by stub
Coupler drives pump.
Wear is on opposite sides.
If you flipped it the drive side would become driven and vice-versa but because its rotation would reverse the same tooth sides would wear.
I have a pump , coupler , drive gear on hand but they are buried due to a home reno.
I will put a good look on the things to do list when I see the old LT1 bin.
Wonder if there is a difference in position of O groove on pump vs drive gear.
Don't know, one would think the difference between the two ends would be pretty obvious if it was the cause of 3 pumps and a drive failure as Marky has indicated.

 

GM wouldn't have spent the pennies to place the groove in one end if it didn't matter

 

As others mentioned, there are other posts here about changing the WP.

But to answer some questions in this thread directly...

Bolts don't need replaced unless rusted or damaged. As mentioned, only one needs thread sealant (you'll know the one when you remove it, a bunch of coolant dumps out from the block, lol). But often I put sealant on them all just to help prevent dirt/rust/seizing.

Coupler groove/line faces the engine.

Briefly mentioned before, but often overlooked is that the coupler needs an o-ring on the mating shafts (both).

100% of the time, this o-ring is missing or fallen apart in every job I've done. Replace it! Do not skip it. If missing, a "Harbor Freight" or Amazon o-ring assortment works fine. Ideally it should be an oil-resistant rubber.

Install the new o-rings, then add liberal bearing grease inside the coupler, then reinstall.

Water pumps last much longer when all of the proper steps are taken. Not saying it's foolproof because I've had a brand new Gates pump leak out of the box. But in theory, the o-rings keep the grease in, and helps dampen vibration. As soon as the grease is lost, the coupler starts to seize or "tightly couple" to the shaft and wobbles/wallows out the WP bearings in short order. I've taken some WPs off that had a seized coupler and the bearings on the WP were completely destroyed, nothing left except a race. Even the balls were missing. Guess what? The coupler was dry (no grease) and stuck on one end of the shaft.

 

Good points Tom ^^^

I will add a contributor to failed mechanical pumps, aside from its MAJOR INHERANT issue of a poor WP housing seal/bearing, is the WP drive spline bearings can wear and the spline (one in motor) will have some play which in turn will cause the whole spline collar to wobble regardless of ne O rings, grease used to install coupler and will kill the WP

I believe that WP drive spline/bearing assembly is extinct or very hard to find let alone what is involved to replace it

But for me being a 22+ year EWP guy....I don't have those problems

 

Side notes...

What we need is a "flexible" coupler. Something with like a U-joint or CV joint. Wonder if that would help? Wish I owned a machine shop...

I mean it's still not a great design either way but I also own several B-Bodies and I don't stress over it. I stick my finger under the WP to check for wetness every time I check oil, etc. I don't even care about minor wetness. Usually a Delco cooling system tablet or two will clear that up (10-108/12378255). If you happen to catch a bigger drip, then don't wait.

I also tried adding a 1/8" nipple and a hose to a particularly leaky reman. Guess what? The nipple and hose clogged up with green goo. So my next experiment was to add a piece of aluminum flashing to simply divert the drips. That worked great until I replaced the WP.

My primary mode of transportation is still a LT1 Caprice. Has been for 25 years. I think people like to berate the system but it's not as bad as people make it sound, especially if good quality WPs are used and proper replacement procedures are followed.

I know some people really like EWPs. I haven't graduated from that class yet, mainly because 20+ years ago, when I was racing, I noted several LT1 cars at the track would overheat with EWPs and the guys hated them. They seemed to do well at idle but couldn't keep up under stress. I knew a guy who tried 3 different brands. Two caused overheating at the track, one worked better but had poor heater performance in the winter (maybe because it was circulating too fast?). Guess they've gotten better since then???

Do all of the people here that run EWPs have any heater problems in the winter?

 

te the system but it's not as bad as people make it sound, especially if good quality WPs are used and proper replacement procedures are followed.

I know some people really like EWPs. I haven't graduated from that class yet, mainly because 20+ years ago, when I was racing, I noted several LT1 cars at the track would overheat with EWPs and the guys hated them. They seemed to do well at idle but couldn't keep up under stress. I knew a guy who tried 3 different brands. Two caused overheating at the track, one worked better but had poor heater performance in the winter (maybe because it was circulating too fast?). Guess they've gotten better since then???

Do all of the people here that run EWPs have any heater problems in the winter?

My car is a daily that will never see a track. Over a year now without issue and the car runs cooler than any other B Body I have owned. Living in Central Florida means she lots of excessive heat but keeps her cool.

I'm in Florida, what is this Winter you speak of? Heater?

Just kidding, contrary to popular belief it still gets freaking cold here. The few times last Winter that I needed heat it was there. My issue is that damn inline restrictor to the heater core. I don't think anyone makes one that doesn't start leaking.

 

The coupler IMHO gives enough " flex " if kept lubed and the alignment dowels are in place.
I have seen water pumps where people have broken the dowel hole out and off brand pumps that did not fit properly resulting in side forces.
Neither the pump , front cover , gear likes that much.

I too tried the gutted nipple and drewl plugged it. Made hole slightly bigger and put a pressed in tube.
It was clear when I went to the electric in search of ET.

My personal experience with electric pump and temps.
Cooler in stop and go traffic
Hotter running down the highway .

 

Yes believe cavitation - erosion was the big thing.
The hole size required to protect at high speed would hinder low speed heat.

Agree, fixed diam orifice for electric pump would be good .
Edit: if needed at all
Never got to it but also a vacuum or electric valve connected the AC max setting to shut off water completely when you wanted MAX cool with no regulation or when on vent .

 

Not only do EWP spin at a fixed rate ,they spin at an optimum rate for transferring heat into coolant from engine. Also for coolant to shed it's heat in radiator. I've never come close to overheating coolant regardless how many laps on road couses. Something else gets way hotter first. Brakes/trans usually ,but P/S fluid is a close contender. If one dislikes EWP for whatever "reason" ,don't use them. Broad generalizations that those of us who've run EWP for decades know to be total B/S doesn't help anyone. Same can be said for the "gossip" surrounding 160 degree stats.

 

Not only do EWP spin at a fixed rate, they spin at an optimum rate for transferring heat into coolant from engine.

I've no way of proving or disproving this statement, but I still have a very strong suspicion that the different electric H2Opumps for LT1s
Meziere WP118 vs WP118HD
CSR had two different pumps
think there was another maker?
have different power consumption and flow ratings.
At best, only one of them spins at the optimum rate.
Things may have changed since that thread I linked, but I bet it's still the WP118HD.

According to the graph in
this post
the OE mech H2Opump peaks @ 66Gallons per Min at 6,000 PUMP RpM.
6,000 pump RpM ≈ 4725 engine RpM.

WP118HD rated @ ≈ 50GpM. Note that this was never measured through an LT1.
All the other electric H2Opumps were rated to flow less than the WP118HD.

 

I would argue the " optimum " speed for a pump is due to impeller design and housing.

The too fast to pick up heat in the block and too fast to have time to release heat in the rad story is ,,,,,,, well,,,,,,,,,

The car over heats with no thermostat because the water moves too fast = sasquatchs and unicorns.
More to due with no restriction = less pressure = more localized boiling

Stewart Components are not idiot's

Home - Stewart Components

www.stewartcomponents.com

 

... the "optimum" speed for a pump is due to impeller design and housing.

Unless GM has a different part number for the '96 LT4 'vette H2Opump - and yet another part number for the '97 LT4 Camaro SS / Pontiac FireHawk LT4 H2Opump - I think it's safe to assume that the LT1 H2Opump was rated to handle 350 peak horses.

... too fast to pick up heat in the block and too fast to have time to release heat in the rad story is ...

long story, too short: backpressure, anyone?

Here's a thought: with a 180 degree F tstat, and coolant moving @ 66 gallons per minute through the system, with both radiator fans blowing, the radiator would still be coldest, the heads would still be hottest, and the average temp of the coolant would approach 195 degrees F ... right?

Does LIQUID coolant ever flow through the steam pipe behind the heads - or just steam?

... Mechanical pumps can only flow water to the point where impeller begins to spin thru coolant (cavitation) which mechanical pump proponents never mention ...

For whatever it's worth ...

To put a sharper point on it a pump impeller ( electric) could be very optimized if it only turns one speed.

Now we need a pic of a mech H2Opump impeller and an electric H2Opump impeller ...

 

I suspect that higher horsepower motors (450+hp) require higher rates of circulation within the motor.
Compared to motors making 300-400hp. Mechanical pumps can only flow water to the point where impeller begins to spin thru coolant (cavitation) which mechanical pump proponants never mention ,nor their relatively poor rates of flow when stuck in city traffic.

 

Mechanical pumps can only flow water to the point where impeller begins to spin thru coolant (cavitation) which mechanical pump proponants never mention ,nor their relatively poor rates of flow when stuck in city traffic.

I will go along with that.
To put a sharper point on it a pump impeller ( electric) could be very optimized if it only turns one speed.

Yes agree with cavitation , pumping a bunch of air around badly doesn't cool very well.
The Chev powered race cars I take care of I get away with running at less than 1/2 crank speed.

 

The only time there is steam or air coming out of that tube is when it is generated or trapped.
Pretty much straight coolant coming out in normal conditions.

 

I had to look up nucleation

 

The lt1 vs L98 pump comparison , to me , is a little misleading.
The open vs closed difference is due to bypass design .
The L98 had only that small bypass port from the pass head to the water pump inlet.
They barely moved any water with the stat closed.
The LT1 has the giant bypass and dual acting thermostat and moves water big time thermostat closed.

I remember a respected member here years ago arguing that a old style thermostat worked fine in the LT1. Yeah maybe 1/4 mile at a time !!

 

Thanks for the details. Based on this, I think the heater issue might be a legit concern in northern states. On really cold days, like 0 degrees F or lower, even with the mechanical pump and fully warmed-up engine struggles to get me heat. And that's on a well-maintained car. If the EWP is 15% colder heat, that will really make a difference down that low of temps. But there's nothing stopping me/anyone from using one on a "summer" only car.

Some folks like reusing the AIR pump circuit for the EWP. But yeah if it were me, I'd be running a dedicated circuit with 10 gauge wiring through a relay and fuse.

 

Thanks for the details. Based on this, I think the heater issue might be a legit concern in northern states. On really cold days, like 0 degrees F or lower, even with the mechanical pump and fully warmed-up engine struggles to get me heat. And that's on a well-maintained car. If the EWP is 15% colder heat, that will really make a difference down that low of temps.

If you are referring to my comments....a EWP has zero effect on heater output. My comments were referring to a 160 stat and fan temps programmed to come on lower thus a much lower "operating" temp relative to cooling system. It is that lower operating temp that mute's heater output compared to a stock system, EWP or Mechanical WP as stock programming and a 185 stat the motor "normal" is running 200 degrees ish and heater is warmer output due to higher coolant temps in cooling system

The lower operating temp due to programming are designed to allow for more timing and fueling for performance purposes

The heater "restrictor" is because a mechanical WP output/flow increases with RPM so there is a restrictor inline to protect the smaller cooling core of a heater core from rupturing when motor sees high consistent RPM use

Given an EWP has constant flow regardless of RPM I would think the restrictor could be abandoned but see no hindrance that it remains

 

I'd prefer a circuit breaker to a fuse ,but that's just me...

 

Sure, that's fine too. I used the term "fuse" loosely there. Because if I hadn't mentioned a fuse, someone like you would probably come in and correct me.