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New water pump install

mduenas

Sr. Member
Joined
Dec 29, 2015
Messages
511
Loc.
Los Angeles
I’m going to attempt today to replace my stock water pump with a high flow. I have a couple of questions before, so I don’t botch things.

I have searched high and low and I can not find this, what are the torque specs for the bolts?

Do I need to use thread sealer on any? Do I need to use any sealant besides the gasket that comes with the water pump?

Anything I should be aware of?

I have a 1974 302.

Thank you!
 

Rustytruck

Bronco Guru
Joined
Feb 24, 2002
Messages
10,875
The bolts are all a different length. take a piece of cardboard and place the new gasket on top and trace all the holes. Then push a pencil through all the hole marks on the card board. Now when you take a bolt off the engine you pop it into the correct hole on the card board.

The bolts going through the water pump in to the block get pretty corroded. I put a thin wipe of silly cone on the bolt shanks to stop the corrosion.

clean the gasket surfaces really well, use the gasket sealer of your choice on both sides of the gasket. If you want a pretty engine clean and paint the water pump before you put it on. Clean and paint all the front of your engine while you have access to it.

Be aware the 1974 had 2 different water pumps for ford 302, A California edition with smog pump and 49 state ford 302 without smog pump. The 49 state pump is a common normal 289/302 water Pump easy to find. the smog pump water pump is about 3/16 inch longer at the fan mount surface. These days much harder to get and usually special order. Compare the 2 pumps (old and New)

I believe your changing to serpentine pulley system so get the right pump for what ever system you are using? The serpentine will use a different pump along with a new timing cover and fuel pump.
 

Timmy390

Bronco Guru
Joined
Jan 1, 2011
Messages
5,609
Loc.
Conway, AR
The last WP I got (think it was a Murray) had a no sealant gasket. I used sealant and it leaked. had to redo my work.

The FelPro gasket I got to redo was also a no sealant gasket. So verify before you apply :)

Tim
 
OP
OP
M

mduenas

Sr. Member
Joined
Dec 29, 2015
Messages
511
Loc.
Los Angeles
The bolts are all a different length. take a piece of cardboard and place the new gasket on top and trace all the holes. Then push a pencil through all the hole marks on the card board. Now when you take a bolt off the engine you pop it into the correct hole on the card board.

The bolts going through the water pump in to the block get pretty corroded. I put a thin wipe of silly cone on the bolt shanks to stop the corrosion.

clean the gasket surfaces really well, use the gasket sealer of your choice on both sides of the gasket. If you want a pretty engine clean and paint the water pump before you put it on. Clean and paint all the front of your engine while you have access to it.

Be aware the 1974 had 2 different water pumps for ford 302, A California edition with smog pump and 49 state ford 302 without smog pump. The 49 state pump is a common normal 289/302 water Pump easy to find. the smog pump water pump is about 3/16 inch longer at the fan mount surface. These days much harder to get and usually special order. Compare the 2 pumps (old and New)

I believe your changing to serpentine pulley system so get the right pump for what ever system you are using? The serpentine will use a different pump along with a new timing cover and fuel pump.

Thank you! That is great advice! I’m actually trying a high flow before I do yhe serpentine setup, as the pump was $53. And if it doesn’t work I’ll return. So it is my last low cost option. This is what I got: https://www.summitracing.com/parts/GMB-125-1420P
 
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mduenas

Sr. Member
Joined
Dec 29, 2015
Messages
511
Loc.
Los Angeles
The last WP I got (think it was a Murray) had a no sealant gasket. I used sealant and it leaked. had to redo my work.

The FelPro gasket I got to redo was also a no sealant gasket. So verify before you apply :)

Tim

It has a paper gasket it came with, instructions say if using a rubber gasket use a certain type of silicone.

So I’m assuming I still need to add silicone to a paper? I have permeated high tack gasket sealent, do I need to wait 24 hours before adding coolant back? Package doesn’t say, but just want to triple check.

Or is the black 3m super adhesive weatherstrip and gasket sealant better to use?
 
Last edited:

B RON CO

Contributor
Bronco Guru
Joined
Jun 29, 2016
Messages
2,412
Loc.
Statesville, NC
Hi, the 3M adhesive is not silicone. I like a permatex silicone gasket maker in a very light coating, inside the bolt holes.
I don't use a torque wrench for a water pump. I go around and across all the bolts gently like 3 times to pull it in evenly and go for what is call medium snug.
The maximum torque for a 5/16 bolt, grade 5 is 17 foot/ lbs, 3/8 bolt is 31 foot/lbs according to my Chilton manual.
I thought the reverse flow pumps had a different size hub so the pulleys wouldn't get mixed up.
Good luck
 
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mduenas

Sr. Member
Joined
Dec 29, 2015
Messages
511
Loc.
Los Angeles
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mduenas

Sr. Member
Joined
Dec 29, 2015
Messages
511
Loc.
Los Angeles
What is the temp reading? More than your thermostat rating? Personally, I run a 192 but that's just my preference.

The temp was at 198 pretty constantly. But again, that wast driving and hood open. I was hoping to stay around 180, maybe switching to the 195 is ideal then, so the thermostat actually works. I know 198 isn't bad at all, and is fairly good. I wanted to be lower so I can run the AC.
 

gr8scott

Contributor
Bronco Guru
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Jul 1, 2011
Messages
1,823
So how long did you let it sit there idling? Did you see the temperature react to the thermostat opening?
You should take it out on the highway and sees what it does.
 

gr8scott

Contributor
Bronco Guru
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Messages
1,823
from your other thread:

I have been doing all of the same things you have for the last year. I think i have mine beat and I think you are close. What i didn't know was how to properly burp the air from the system. Broncobowsher posted the filler neck for the high upper hose and that's what fixed me. Here is a link to a bad video i made burping. I removed air bubbles for over 30 minutes and then never had the cooling issue again. I ended up with a mechanical fan and a 195 stat, just dialing in the depth now.

YouTube video
 

Bolt

Newbie
Joined
Sep 28, 2018
Messages
35
Just switched out a stocker gmb pump (leaking with less than 200 miles) to a high flow gmb pump and I’ve had nothing but problems. Temp now running 190+ at idle so I dropped a 165 stat in which didn’t help. It never got over 180 with the stock pump even if the coolant was a quart low. Im thinking about going back to a stock pump. Temp drops immediately in the wind. I figure it’s an airflow issue but confused because I didn’t have this issue prior to the high flow.
Ron Davis radiator with aluminum shroud: stock fan.

Any ideas?
 

B RON CO

Contributor
Bronco Guru
Joined
Jun 29, 2016
Messages
2,412
Loc.
Statesville, NC
Hi, 190 is nothing to worry about. Put in the 180 thermostat. How are you reading the temp? I use a digital thermometer on the thermostat housing. I would probably drive it a while and see how it goes. Make sure your ignition timing is set properly. Good luck
 

Bolt

Newbie
Joined
Sep 28, 2018
Messages
35
I was mainly relying on the gauge which has always been consistent. I will shoot it with the digital. Initial run it jumped to over 200 at idle but that was due to air in the system. Why do you think this high flow pump is running hotter?

Thanks for your comments. More frustrated than anything after putting a year and half into the build.
 

DirtDonk

Contributor
Bronco Guru
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Nov 3, 2003
Messages
47,355
Hey Bolt, welcome to classicbroncos! Sorry to hear you're having an issue after what should have been a simple pump swap.

Just switched out a stocker gmb pump (leaking with less than 200 miles) to a high flow gmb pump and I’ve had nothing but problems.

Already sounds like the pump(s) are defective. Leaking out the weep hole at 200 miles is an example of the typical imported crap/junk we're being given these days. Lots of discussions about it with other parts. Not so much the water pumps.
But I thought GMB was Japanese? If so, I'm surprised that you got one, or two bad ones.

Is it leaking from the weep hole though? Or a gasket surface?

Temp now running 190+ at idle so I dropped a 165 stat in which didn’t help.

No, I wouldn't have expected it to. As said, 190 isn't much. But the fact that it did not do it before you made the change is strange. Maybe you knocked the coolant temp sensor wire while working on the pump and it changed the old readings? That's a long shot I know, but stranger things have happened.

It never got over 180 with the stock pump even if the coolant was a quart low.

Yeah, I've run mine almost empty and it did not overheat until I was at least 2/3 of a radiator low on coolant.
Did you change the ignition timing in any way perhaps? Did you mess with the distributor, or anything else for that matter?

I'm thinking about going back to a stock pump.

You could do that. It does not sound like you were having trouble with a stock replacement, but no matter what, you're having trouble with the quality of the pumps at this point. Leaking so soon? Not an engine issue, but a pump quality issue.
Unless it was indeed a gasket that was leaking. In that case, it could be a warped pump housing, or a warped engine housing.

Temp drops immediately in the wind. I figure it’s an airflow issue but confused because I didn’t have this issue prior to the high flow.

If you changed the water pump only, it's not an air flow issue. Remember that your water pump is running faster at this point too.

What about the fan? Double check it to make sure it's not on backwards.
If you're running a v-belt system, then the pump and fan turn clockwise. Make sure that the fins are pointing in the right direction.

About the pump, any chance that you didn't notice a possible difference in design/shape from your old one to the new one? Could it be a reverse rotation pump that's being used in a standard rotation setup?
Either the fan or the pump running backwards of intended would do strange things.

Ron Davis radiator with aluminum shroud: stock fan.

Should be good I would think. Maybe you also got a bad new thermostat?
That's the problem with the parts these days. You used to be able to count on a new part working so you could check it off the list of culprits. But now you not only have to look at the old parts with a keen eye, but the new ones as well.
Lots of bad thermostats around here too.

I'm always on about "coincidental failures" on our rigs. Where you go to fix one thing, and something else entirely decides to fail at that same time. So in your case, changing a water pump could be accompanied by a failing distributor timing mechanism, retarding the timing and causing the engine to run hotter.
But if the pump is the only thing you touched (other than the front accessories) then you still have to concentrate on those first.

So:
1. vacuum leaks.
2. ignition timing.
3. fan direction.
4. defective thermostat.
5. Defective new pump(s)
6. Best of luck! Check!

Paul
 

Bolt

Newbie
Joined
Sep 28, 2018
Messages
35
The pump was leaking out of the weep hole (cast iron repop). I’ve run 3 different stats, so eliminate that. Timing is good. In the wind the temp
Drops to whatever stat I’m running but over 10 min at idle and it climbs to 195.
 

Bolt

Newbie
Joined
Sep 28, 2018
Messages
35
I checked the fan and pump rotation and all good there. We are pulling air and not pushing air. If you think gmb is the issue what would you recommend?
 

DirtDonk

Contributor
Bronco Guru
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Nov 3, 2003
Messages
47,355
Well, I'm a bit biased. But both ways!
I've used GMB with great success both under their own name (stock replacement, but with aluminum body) and as the core for two different FlowKooler high-flow water pumps.
All three lasted many years and many miles.
We sell the FlowKooler brand (why I said I'm biased) but don't know if the cores are still supplied by GMB or not.

But with my experience being so good with them, I don't know who else I'd recommend.
I'm a fan of the FlowKoolers because of the impeller design and performance. But pumps from Moroso, Edelbrock, Stewart Performance and other big name accessory companies have all been generally good. Including the ones from GMB.
If they're suffering from poor quality, I'd say it's a more recent event. Lucky you... Right?%)

Now I'm curious. I'll have to see if I can find out if GMB is still making the cores for FlowKooler or not. We have not had any trouble with them that I'm aware of.

Maybe others will have their recommendations.

Paul
 

Rustytruck

Bronco Guru
Joined
Feb 24, 2002
Messages
10,875
Just make sure that any waterpump you buy is a new waterpump and not a rebuilt. Same thing with mastercylinders. Theres too much work to properly replace so why go with some cost cutting low bidder.
 

Bolt

Newbie
Joined
Sep 28, 2018
Messages
35
I have an aluminum body standard flow that I’m contemplating installing today.not the for the lack of anything better to do but more fro my own sanity. I did change out the temperature sending unit with no results and while I was working at some point, I removed the distributor cap and replaced it. Could something be off there?

I’m Pretty sure gmb is still making the housing for flow cooler.
 
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