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Username Post: Water pump opening on block        (Topic#353624)
PLS 
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PLS
Loc: Smyrna, Georgia
Reg: 06-07-12
10-27-18 09:44 AM - Post#2749690    

The picture that is attached is of a 1998 GMC C1500 4.3 engine showing the driver’s side water pump opening. I would like to know if the bottom hole is supposed to be bottomless, this one is but the other three are not. If it is how do you prevent water from leaking. I had a new water pump installed about three years ago and this week it started to leak but I couldn't tell where it was coming from because of all the "stuff" on the front of the engine. I removed the A/C bracket and the alternator bracket and still couldn't really tell where it was coming from so I started to remove the water pump bolts. I loosened the two on the passenger side and the top one on the drivers side and the pump moved even though I hadn't loosened the bottom one on the drivers side yet and looking at it closer I could tell that there was a small gap between the head of the bolt and the water pump flange. When I started to take it out it was extremely tight and I was afraid it was going to twist off but I did get it out. Thank you in advance. Lamar (the way that the picture came out the bolt that I said was on the right is actually on top )

Attachment: IMG_5562.JPG (1.68 MB) 14 View(s)


The hole on the bottom is the one in question.


Attachment: IMG_5565.JPG (1.16 MB) 17 View(s)


The bolt on the right is the bolt in question and it is a little shorter than the three on the left and it's head is a 13mm, the three on the left has a 14mm head.




Edited by PLS on 10-27-18 09:52 AM. Reason for edit: No reason given.

 
raycow 
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raycow
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10-27-18 10:09 AM - Post#2749692    
    In response to PLS

If you believe the leak is coming from that one hole which is open to the water jacket, the easiest fix would be to use sealant on the bolt threads. If the leak still persists after that, then you will have to find out where it is actually coming from.

Ray

Those who choose an automatic transmission want transportation. Those who choose a manual transmission want to drive.


 
PLS 
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PLS
Loc: Smyrna, Georgia
Reg: 06-07-12
10-27-18 10:33 AM - Post#2749693    
    In response to raycow

Thank you Ray. I’m reasonably sure that is where it is coming from. I saw the bolts on Advance Auto website and all four bolts seems to be the same and they have sealant already on the threads. I may just clean the ones that I have and apply sealant but the puzzling part to me is why the different bolt on the bottom and why it wasn’t tight against the pump flange yet extremely tight in the hole. Do you know if that hole is bottomless? Lamar



 
454cid 
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Age: 46
Loc: West Michigan
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10-27-18 04:04 PM - Post#2749724    
    In response to PLS

  • PLS Said:
Thank you Ray. I’m reasonably sure that is where it is coming from. I saw the bolts on Advance Auto website and all four bolts seems to be the same and they have sealant already on the threads. I may just clean the ones that I have and apply sealant but the puzzling part to me is why the different bolt on the bottom and why it wasn’t tight against the pump flange yet extremely tight in the hole. Do you know if that hole is bottomless? Lamar



I would guess someone has been there before you, and possibly replaced one bolt or three, and maybe forgot to tighten the one bolt.

I typically clean bolts up and reuse them... it's cheaper and keeps things original. However, those bolts look pretty bad. It wouldn't hurt to clean them up to see what you have, but I think I'd look towards getting replacements, along with new gaskets.



99 K3500 RCLB


 
454cid 
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10-27-18 05:25 PM - Post#2749732    
    In response to 454cid

I believe those bolts are supposed to be 3/8-16 X 2-1/8". I found the Dorman part number and Dorman's website gave me the GM number. The GM number corresponds to a bolt the size I mentioned above.

So the bolts you have with the 14mm heads are probably really a 9/16" head, and are the correct bolts. The 13mm head bolt is probably wrong... metric or otherwise, but probably a 10mm thread that was forced.

99 K3500 RCLB


 
bowtie44s 
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bowtie44s
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10-27-18 06:08 PM - Post#2749734    
    In response to PLS

Every small block I've worked on had American bolts and the water pump has 5/16 bolts. That should be a 1/2 or 13 wrench. Use a little thread sealant on the threads.

Jeff

'88 Chevy K3500, aluminum head roller cam 511in³ stroker 10.5:1 compression, 96 NV 4500, 94-98 grille, 305/70-16 (33x12) BF Goodrich KM2s, 91 cluster swap


 
PLS 
"7th Year" Silver Supporting Member
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PLS
Loc: Smyrna, Georgia
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10-27-18 08:05 PM - Post#2749737    
    In response to 454cid

I want to thank you and bowtie44s for you help. I just got home and I checked the bolts by tracing the threads with a die and 3 are 3/8-16 X 2-1/8”. The 4th bolt wouldn’t even begin to start in the die. I check the heads and you are correct a 9/16 socket fits the three perfect as well as the 14mm. The 13mm fit the 4th bolt head good but the ½” socket was a tight fit and I believe as you said it is wrong and they must have picked up a bolt laying around and forced it in and thought that it was all the way in because of how tight it was. I was afraid that the threads would be damaged after you mentioned the bolt may have been a 10mm and was forced in but I tried one of the other bolts and it screws in just as easy as it does in any of the other holes. I already have the new gaskets and I think that I will just get new bolts as well.
The truck belonged to my neighbor and when he passed away in 2010 the family gave it to me. While he owned it, I replaced the pump for him and as I said in my original post I had it replaced again about 3 years ago because I didn’t have the time to do it myself. Thank you very very much for your help. Lamar





 
454cid 
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10-27-18 10:19 PM - Post#2749744    
    In response to PLS

You're welcome.

99 K3500 RCLB


 
raycow 
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raycow
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10-28-18 12:50 AM - Post#2749748    
    In response to PLS

  • PLS Said:
.....Do you know if that hole is bottomless? Lamar


I honestly don't know if that hole is open to the water jacket, but from your description, it sounds like it is.

Ray

Those who choose an automatic transmission want transportation. Those who choose a manual transmission want to drive.


 
rockfangd 
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rockfangd
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10-28-18 08:00 AM - Post#2749763    
    In response to raycow

It has been awhile since I did one but IIRC there was a hollow one.
Lucky you got that bolt out without breaking it.


Old School GM fan FOREVER


 
bowtie44s 
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bowtie44s
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10-28-18 10:10 AM - Post#2749772    
    In response to PLS

I was thinking 5/16 but now that you said 3/8 that sounds right. It's been a while. The LS is metric, but the old small blocks and big blocks are American.

Jeff

'88 Chevy K3500, aluminum head roller cam 511in³ stroker 10.5:1 compression, 96 NV 4500, 94-98 grille, 305/70-16 (33x12) BF Goodrich KM2s, 91 cluster swap


 
454cid 
Valued Contributor
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10-28-18 12:19 PM - Post#2749776    
    In response to bowtie44s

  • bowtie44s Said:
I was thinking 5/16 but now that you said 3/8 that sounds right. It's been a while. The LS is metric, but the old small blocks and big blocks are American.



A size change could have happened with the Vortec engines, too.


99 K3500 RCLB


Edited by 454cid on 10-28-18 12:20 PM. Reason for edit: No reason given.

 
PLS 
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PLS
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10-30-18 03:18 PM - Post#2750023    
    In response to rockfangd

  • raycow Said:
I honestly don't know if that hole is open to the water jacket, but from your description, it sounds like it is.

Ray


Ray, I'm reasonably sure that the bottom hole is supposed to be bottomless.


  • rockfangd Said:
It has been awhile since I did one but IIRC there was a hollow one.
Lucky you got that bolt out without breaking it.



As I told Ray, I believe that the hole is supposed to be bottomless. You are correct that I was lucky in getting it out without it breaking. Actually as I was turning it I thought that it was twisting rather than backing out.

I checked the odd bolt and it is a 10 x 1.5mm. I cleaned up the three correct one's and bought a new one and drove it today and everything seems to be working fine . I want to thank everyone who helped me in my time of need and for this website allowing guys and gals to help out other guys and gals literally all over the world. Lamar



 
rod 
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Loc: kingman,az
Reg: 04-29-00
10-30-18 05:37 PM - Post#2750040    
    In response to PLS

as with many other things automotive nowadays...water pump gaskets fail. they seem to rot away.
as far as the holes, some are blind [265s had all holes blind]some are open. it should not be a problem. if you have an open hole, use sealant. chase the threads and possibly use a bottle brush to clean the threads. use sealant on both sides of the gasket. torque to 26 lbs [American]. extra safety, use washers if you dont use washer head bolts.
Rod in AZ





 
PLS 
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PLS
Loc: Smyrna, Georgia
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11-12-18 11:06 AM - Post#2751156    
    In response to PLS

Well I just thought that I had corrected my water leak. After driving the truck a few days, I began to see a small water spot under the truck and it seemed to get bigger after each drive. It only leaked while hot and after it cooled down the water would dry up until the next drive. Got a loaner system pressure tester from Advanced Auto and put about 10 pounds on it and the water really came out but couldn’t tell where it was coming from. Got under the truck and the water was running down off the back of the engine and then off the transmission. Once the water got below the leak area, I could hear air but still couldn’t tell where it was coming from. Removed everything from the front of the engine once again, shroud, fan and the power steering pump/A/C bracket. Filled it up with water and pumped it up to 10 pounds and there was no doubt now as to where it was coming from, the front driver side intake manifold, just what I needed. After two days of removing “stuff”, just to be able to see the engine, I got the intake removed. After looking the manifold over I noticed that the second hole from the back, driver’s side, was notched but looking closer it looks like a small piece is missing and from the condition of the broken surface it has been missing for quite a while. Since the final torque value according to the Haynes manual is only 11 Ft-lbs. after first the first two in-lbs. sequence, I’m considering reusing it because I really don’t want to open up another can of worms because of having to deal with the fuel injectors. Any thoughts? There is one bright spot, with everything removed, I can stand inside the engine bay and work on it. I can just stand on the floor but I placed an 8” wooden box under the truck and stand on it and can reach everything. Lamar



Attachment: IMG_5678.JPG (726.54 KB) 14 View(s)




Attachment: IMG_5680.JPG (123.04 KB) 17 View(s)


I use to kid about being able to work on my ’70 Chevy PU in the rain because there was enough room to climb into the engine bay and close the hood. Well it works on the ’98 also. 😊


Attachment: IMG_5622.JPG (122.42 KB) 14 View(s)






 
454cid 
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11-12-18 01:06 PM - Post#2751166    
    In response to PLS

For the 350 V8 there is an updated gasket set available and since the V6 is based on it, I would think there is an updated set for it too. Unfortunately, I don't have specific information.

99 K3500 RCLB


 
MiragePilot 
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Loc: Tucson, AZ
Reg: 08-18-16
11-12-18 02:23 PM - Post#2751174    
    In response to 454cid

FelPro gaskets are the preferred replacement for the intake manifold gasket R&R jobs.

Peter


2002 Chevy Express 1500 conversion van (Explorer SE conversion)

RIP (totaled in Feb '18): 1996 Chevy Express 1500 conversion van (Starcraft Hi-Top Conversion)


 
PLS 
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PLS
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11-12-18 03:56 PM - Post#2751183    
    In response to PLS

Thanks, guys, for your input on the gaskets. I haven’t purchased the set yet but these are the ones that I have looked at. Also, the spark plugs are Autolite Platinum AP 605. I don’t know if these are the original ones or not but they all look like the picture and seem to be in pretty good shape for 122000 +miles if they are the original, I got the truck from my neighbor when it had 88000+. The gap is still .060.

Attachment: intake_gasket.jpg (12.68 KB) 15 View(s)


Felpro Intake Manifold Gasket Set Part # MS 98002 T


Attachment: IMG_5703.JPG (612.41 KB) 15 View(s)






 
MiragePilot 
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Reg: 08-18-16
11-13-18 12:18 PM - Post#2751284    
    In response to PLS

Looks like you are on the right track. That FelPro gasket set looks familiar...I went through this exercise on my 5.7 V8 a few years ago.

Peter


2002 Chevy Express 1500 conversion van (Explorer SE conversion)

RIP (totaled in Feb '18): 1996 Chevy Express 1500 conversion van (Starcraft Hi-Top Conversion)


 
PLS 
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PLS
Loc: Smyrna, Georgia
Reg: 06-07-12
11-14-18 08:48 PM - Post#2751438    
    In response to PLS

Could someone tell me what the 4 O-rings in the Felpro gasket set are used for? Lamar

Attachment: 15780798_fel_ms98002t_pri_larg_1_.jpg (33.95 KB) 17 View(s)






 
MiragePilot 
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Reg: 08-18-16
11-15-18 03:43 PM - Post#2751501    
    In response to PLS

The middle two go on the (hard) fuel line fittings that you have to disconnect in order to remove the upper intake manifold. I can't remember what the other two were used for.

Peter

2002 Chevy Express 1500 conversion van (Explorer SE conversion)

RIP (totaled in Feb '18): 1996 Chevy Express 1500 conversion van (Starcraft Hi-Top Conversion)


 
PLS 
"7th Year" Silver Supporting Member
Posts: 1399
PLS
Loc: Smyrna, Georgia
Reg: 06-07-12
11-15-18 07:21 PM - Post#2751517    
    In response to MiragePilot

I contacted Federal-Mogul this morning concerning the O-rings and got a pretty quick reply. It was a little confusing because I couldn’t find where my engine has a “fuel rail” so I checked the hard fuel lines from the tank and one of them had an O-ring but the other one didn’t so I just used the ones that fit best. I have it all back together except for the alternator, compressor/power steering pump brackets and hope to get them done tomorrow and try everything out to see how it goes. Thank you very much for your help. Lamar
This is the reply that I got: Thank you for the inquiry.
Two O-rings are for the fuel rail, One for the brake booster and one for a sensor that screws into the manifold.
Matt-0490
From The Federal-Mogul Motorparts Product Support Team
Please Call The Federal-Mogul Motorparts Techline @ 800-325-8886.



Attachment: IMG_5720.JPG (129.76 KB) 17 View(s)






 
PLS 
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PLS
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01-08-19 04:15 PM - Post#2756909    
    In response to PLS

Well it's been around 2 months and around 300 miles since the repair job and everything seems to be doing just fine. It got around 1 mpg more after the work. Thanks to all for your input. Lamar



 
CowboyTrukr 
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01-10-19 06:47 PM - Post#2757071    
    In response to PLS

Sweet! Good news, Lamar


Greg

'95 K1500 Z71 EC Short Step 5.7L+0.040/NV3500
'00 Explorer XLT 4.0 V6 Auto
'94 K2500 5.7 NV4500 ECLB - SOLD
‘87 GMC S15 SCLB 4.3 Auto - SOLD

"The only thing necessary for evil to triumph is for good men to do nothing" Sir Edmund Burke


 
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