Has anyone every caused a leak by pressure washing their engine before? Yeah, well me neither until yesterday. I applied gunk to the motor to loosen caked on/baked on grease. My wife and I noticed a bit of burnt oil smell on long drives, so hence the pressure wash. Just after the wash, I noticed coolant leaking from the front of the motor. At the time I couldn't tell if it was coming out from the weep hole or at the block. I can see some orange RTV around the water pump. Could it be possible I blew out some RTV with the high pressure water, causing a leak? It looks like it is coming from above the bolt where the power steering pump bracket attaches to the front of the block....kinda hard to tell but it definitely is coming from the left side of the block, not the weep hole. Tomorrow, I'll use my bore-scope camera to see if I can precisely locate the source.
I ordered a new AC delco water pump and gasket, which should arrive early next week.

When I was searching for the source I noticed a bolt is missing from the timing chain cover! How long should this bolt be?

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Lastly, do the water pump bolts go in blind or into the water jacket?

Thanks

 

Side bolts go into a blind IIRC. But not the bottom center bolts. They go right into the cover in front of the timing chain.

Depending on the intake, as aluminum is normally worse to offend, check the corners of the intake and block. Sometimes galvanic corrosion is bad enough to cause a leak from the corner but it seeps down the front or rear of the block. If nothing else, get some coolant dye and a blacklight flashlight and search for those stubborn to find leaks that way.

Bolt is 3/8-16 x 3/4", with hex flange head. GM p/n 9439905. You can still get them new from GM as it shows as a good number still. List for 7 bucks and change. If you get a discount, that's even better.
AMK sells the HFH 3/4" bolts as well. Pack of 10 for 12 bucks plus shipping. Just an option.
Bulk Fasteners Products — AMK Products, Inc.

 

I think it's more likely that the leak has been there for a while and pressure washing simply removed gunk that was slowing it or redirecting it to a place where you didn't notice it. The 1/4-20 bolts on the water pump are self-tapping and only thread into the sheet metal front cover. Failure to follow the factory torque specs frequently leads to stripped threads. As noted, the two bottom ones go into the timing chain space, so not the water jacket, but if they are stripped the gasket will leak coolant there.

 

Thank you, gentleman. I was looking at the torque specs on the '77 Olds service manual earlier. I'm hoping I don't have stripped bolt holes to deal with. I never look forward to water pump jobs...there is always so much in the way or attached to it that needs to be removed or set aside. Speaking of which, I'll post a couple of pics of the air pump and have questions on how to remove it.

 

I found this bolt in a box of odds and ends fasteners. So the thread pitch was the same, just not the length. I suppose I can machine this bolt down to the correct length. I found the correct length bolt but without the flange. I can always add a washer or just keep looking...one is bound to turn up.

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After using the bore scope camera, I determined that the leak is coming from between the water pump and the timing cover. The new pump and gasket will be here soon enough. Now for the disassembly...

 

Just want to mention ...... I hope you have better luck with the AC Delco water pump than I did with the last one I got. It lasted less than 2000 miles before it started leaking from the seal.

Also, take a very good look at the gasket that comes with the pump. The one I got did not really match the pump body.

If the nipples that the heater hoses go on are actually part of the pump casting I would not use it, period. I did a lot of research the second time and pretty much figured out that the good pumps have steel nipples pressed into the cast pump body just like the originals. I ended up using a GMB pump and it has been fine. I bought it at NAPA.

I am normally a die hard AC Delco fan but I have been disappointed several times lately.

 

Thank you Bill. I wish I had posted before I ordered the water pump.
Thanks for the heads up.

 

Well I drained the coolant from the radiator and removed the lower radiator hose. I also removed the fan shroud, fan, air pump and bracket, loosened the alternator. For the life of me, I cannot figure out how to adjust the tension on the power steering pump! As a matter of fact, I can't see a power steering pump bracket that is slotted so it can adjust. This is the only thing keeping me from removing the water pump.

 

On my Wifes 84 you have to loosen the belt and then go through one of the holes in the pulley to get to the bolt to loosen it. I think there are actually 2. You can get to one with a wrench but the other one you have to go through the pulley The only other choice is to pull the PS pulley which is what I think I did. It is a royal pain Thats why I was so PO'd when the AC Delco pump failed so soon. I had the engine completely apart to rebuild the first time so it wasnt so bad.

I think Joe has posted some parts diagrams here in the past that showed all of the bolts and spacers. What year and what engine are you working on ? I might have something.

 

Thank you, Bill. It is a '77 Cutlass Supreme with the 5.7
I'm going to look in the Olds service manual as well.

 

Should be similar to our 307. I know I had to take half of the front end of the engine apart But ours has all of the OEM AC, AIR Pump etc on it. All of that stuff had to come loose to get the water pump off.

Someone else mentioned it but I will repeat, 4 of the screws are self tapping ones. You do not want to over-tighten them and strip them. snug is good

 

I should probably make this a sticky...

 

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Well at least now I now how to adjust the belt tension after I get it put back together. I didn't see the slot from underneath the car...I suppose I simply missed it. I think from what I read, I'm going to have to remove the brackets to the power steering pump from the block.

 

Thank you too, Joe! Seeing the picture certainly helps.

 

Leave the brackets attached to the pump. Loosen the bolts to remove the belt. Unbolt the brackets from the block and lift the pump with attached brackets away from the block and set it aside in the engine compartment. Don't forget the rear bracket to the bottom side of the block - there's a bolt there.

 

Thanks again, Joe. I did see the bottom bolt holding the bracket to the side of the block.

 

Pay attention to the various spacers between the PS pump bracket and the block. If you lose these your next post will be asking about belt alignment.

 

You're assuming I can even get the car put back together!! lol Just kidding
Thanks for the heads up. I'll report back.

 

Well I finally had time yesterday to finish the job. I'd be a lousy flat rate mechanic as it took me all day to get it back together! I'd say in all, time spent working on it was about 16 hrs over three days. Anyhow, I replaced the water pump, replaced some worn fasteners and got the car running...no leaks. Speaking of leaks, while underneath the car, I noticed the steering gear is leaking fluid. I don't know when I'll take on that job. I have seen that you can purchase a reseal kit for it.

Joe, Bill, thanks so much for your help.