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So got everything up and running actually made a car show last weekend I was shooting for. However the car went from the shop to the trailer, to the covered booth it was in, lol. I been fighting power steering leaks so no power steering, and barely zero Road time. I bought some really nice stainless steel lines to convert the type 2 power steering pump to the factory slave cylinder. Well today I think I got that fixed, had to take the line apart and reinsert the brass crimp fitting.
went for the first real drive just now, a little Hwy and a Littel town action to hit some traffic and see if she stayed cool. All looks good, it definitely likes both cooling fans on but that may also be a function of not having a hood. I pulled over to look at everything and noticed coolant on my head and what look like coolant at the backing plate of the pump. Made it home no problem so no idea why it pushed some out but appeared to seal back up.
I fought this when I first got the engine running, the first test drive it blew the gasket on the backing plate of the water pump. Had to tow it home which is always fun. I read on this forum where someone had the same issue with their Proform pump. I ended up putting a Felpro gasket on it and it did it again. This was mostly my fault because I wasn't running a pump bypass line so it was building pressure and blowing the gasket. I been an SBC guy all my life, first BBC so I learned something!
well a few weeks ago, I got Summit to send me another pump (same kind) and immediately changed the gasket to a Felpro because they come with that cheap cardboard crap. I
now installed a bypass line and I went to that show last weekend. Well just after my drive today I see this coolant on the head in the pic below. It is for sure still coming from the pump gasket.
Now I don’t think I can trust this thing, so I am thinking of going to a different pump all together. I am considering the Edelbrock unit, while double the cost of this pump at $400 it’s pricey but maybe better?????
anyone have a similar issue? Got any suggestions or experience with other pumps?
Me neither. Never. Not in almost 50 years of having one big block or another. If you're blowing backing plate gaskets, there's most likely a defect in the pump.
Yeah, I have never seen this before either, my first BB but still never an issue on an SBC. Maybe a bad run during manufacturing? I think I’m gonna return this thing and swap out for an Edelbrock. Kinda crazy that an Edelbrock pump is $400 but it’s American made, they are typically known for high quality products so maybe I’ll give them a try and see how it goes.
From: I tend to be leery of any guy who doesn't own a chainsaw or a handgun.
What kind of cover is on your pump?
Just one man's experience here. I never had a problem with a leaky rear cover until recently. I had a BB pump apart as it needs new bearings, and the stamped steel cover felt heavier than I liked (I've put my car on a diet for several years). I made a cover out of aluminum and put it on my present (aluminum) pump while I had it off for other reasons. Ran a track day with it, and noticed it leaking. Back home I took the pump off and replaced the gasket. Another track day and it leaked again. I temporarily gave up, and put the heavier steel cover back on as I don't presently have the spare time to keep experimenting with this modification. Haven't had the chance to do a track day since, so I don't know if the issue is resolved or not.
I've done a few simple calculations to figure out how much pressure and force is on the cover, and wondering if the aluminum cover plate is distorting sufficiently under pressure and allowing the leak to occur.
Just one man's experience here. I never had a problem with a leaky rear cover until recently. I had a BB pump apart as it needs new bearings, and the stamped steel cover felt heavier than I liked (I've put my car on a diet for several years). I made a cover out of aluminum and put it on my present (aluminum) pump while I had it off for other reasons. Ran a track day with it, and noticed it leaking. Back home I took the pump off and replaced the gasket. Another track day and it leaked again. I temporarily gave up, and put the heavier steel cover back on as I don't presently have the spare time to keep experimenting with this modification. Haven't had the chance to do a track day since, so I don't know if the issue is resolved or not.
I've done a few simple calculations to figure out how much pressure and force is on the cover, and wondering if the aluminum cover plate is distorting sufficiently under pressure and allowing the leak to occur.
interesting, what pump are you running? This is a Proform aluminum pump, it has the stamped Steele backing plate it came with. I thought for sure the bypass hose fixed the issue. After I swapped this pump on I even put a gauge on the radiator to make sure pressures were not getting real high. Always saw between 11-13 psi on the gauge plus the cap is 13psi so much more should blow the cap.
not sure what the hell is going on but this is about a simple of a setup as it comes. I may just try another pump
Have you tried laying a flat edge across the pump machined surfaces? Is it really flat? Maybe run a file across it to see if it makes good contact. Pump and plate.
It's not a bypass issue. I haven't run one on mine for 20 years spinning 8K RPM regularly with stock pulleys.
I've been using the same Weiand Team G pump for most of those years. Actually it's the 2nd one as a rapidly disassembling harmonic balancer knocked the original one off the engine...but that was over 15 years ago.
I use the Edelbrock pump. No issues.
Also it has the flat screws, so there is no need for grinding the pump cover bolts to fit the thick aluminum timing chain cover
Have you tried laying a flat edge across the pump machined surfaces? Is it really flat? Maybe run a file across it to see if it makes good contact. Pump and plate.
It's not a bypass issue. I haven't run one on mine for 20 years spinning 8K RPM regularly with stock pulleys.
I've been using the same Weiand Team G pump for most of those years. Actually it's the 2nd one as a rapidly disassembling harmonic balancer knocked the original one off the engine...but that was over 15 years ago.
JIM
no I have not checked with a straight edge, seems odd to have two pumps in a row with the same issue. I wouldn’t think RPM is the issue either, this thing is done at 6,500. When I take it back off I’ll give it a look out of curiosity.
I use the Edelbrock pump. No issues.
Also it has the flat screws, so there is no need for grinding the pump cover bolts to fit the thick aluminum timing chain cover
Thanks, I didn’t realize they ran flat screws. I think I’m gonna go with and Edelbrock. Lots of good discussions with them and Stewart pumps.
Danish Shark might be on to something here.
Hard to tell in the photo but it looks like the W.P. is truly contacting the timing cover bolts. So when you think you are torquing down the W.P. bolts against the block for a good seal, in reality the gaskets are not sealing. It would be equal to finger-tight bolts.
That is one thick timing cover. See if you can even get a piece of paper between W.P. back cover & timing cover bolts.
I have seen in some circumstances where a thin spacer moves the W.P. forward. Of course this effects all pulley alignments.
You can likely use that W.P. Just pull it off again and take one of back plate bolts to the hardware store. Look for something flatter.
Danish Shark might be on to something here.
Hard to tell in the photo but it looks like the W.P. is truly contacting the timing cover bolts. So when you think you are torquing down the W.P. bolts against the block for a good seal, in reality the gaskets are not sealing. It would be equal to finger-tight bolts.
That is one thick timing cover. See if you can even get a piece of paper between W.P. back cover & timing cover bolts.
I have seen in some circumstances where a thin spacer moves the W.P. forward. Of course this effects all pulley alignments.
You can likely use that W.P. Just pull it off again and take one of back plate bolts to the hardware store. Look for something flatter.
It for sure is really close but it doesn’t touch, after I had the pump off the first time I looked at it closely, can’t get a piece of paper in there but it’s not touching. I like that the Edelbrock uses flat bolts, more clearance is not a bad thing.
Just make sure that if you get a new pump, its Vette specific. Correct shaft, correct distance from block and the correct bolt pattern. Basically, there are Short, Long and Vette pumps.
Just make sure that if you get a new pump, its Vette specific. Correct shaft, correct distance from block and the correct bolt pattern. Basically, there are Short, Long and Vette pumps.
interesting, I did not order a corvette specific pump before, how would this affect anything? The engine doesn’t care what car it’s in, it’s just a BB. What do you anticipate chasing an issue not being corvette specific?
I would call them up and verify that you ordered the correct pump. It is pretty important.
On my 427 after rebuild I used a Stewart Pump and it worked well on a high compression BB. I switched to a Edelbrock to go to an aluminum body water pump when they had a good sale on the pumps.
The pressure ratings for the radiator caps is primarily done to help with engine cooling. By raising the pressure they get more effective cooling and raise the boiling point of the engine coolant. Water will boil at 212* with zero pressure in the cooling loop. If you put a 16 lb radiator cap on the cooling loop it raises the boiling point to approximately 261*.
On a higher compression engine it is wise to run more water than anti-freeze in your coolant mixture. If you live in Wisconsin you might need more freeze protection but where I am in Northern Virginia I need more cooling than freeze protection so I run 30% anti-freeze and 70% distilled water in my engine's coolant. 50/50 is a standard that many use but on my HOT engine I need to get the heat out of the block. Pure distilled water can be used but you would have to add some lubricant for your water pump's bearings and seals. Anti-freeze usually has lubricants in it to protect the water pump.
To help your engine stay cooler put some Red LineWater Wetter in the coolant and it can drop the heat levels even more. When an engine block gets hot a layer of tiny bubbles forms inside on the metal surfaces which slows down the transfer of heat. Water Wetter will allow the coolant make direct contact with the engine block and more heat can be extracted. There are several companies that have started producing a similar product but I have used the Water Wetter with great results.
interesting, I did not order a corvette specific pump before, how would this affect anything? The engine doesn’t care what car it’s in, it’s just a BB. What do you anticipate chasing an issue not being corvette specific?
On a '69 model, as long as you get a short pump with the 5/8'' pilot shaft you are OK. (Make sure your pulley is for the 5/8'' shaft)
The "Corvette specific" thing is for later 3/4'' pilot shaft models, where Chevy generally started using the long pump, but made a Corvette specific short pump with the 3/4'' diameter pilot shaft
Wen I replaced the water pump on my diesel later summer , the manufacturer state its normal for the seals to "weep" a bit until they swell and seal. I dont recall even having to do this on my vette though... So I have a small block, but...
I installed a skip white ebay aluminum short water pump myself and did away with the corvette stock pulleys but the c3 vette specific water pumps are a mix of short and long water pump parts from what I can tell. All the vette pump does differently is locate the pulleys in a different position so they all lineup. if your running aftermarket pulleys and accessory brackets you do not want the stock corvette style pump.
Last edited by augiedoggy; May 9, 2023 at 10:40 AM.
First off. When you buy a water pump don't muck with the back cover. I've never had the back cover leak. Going to what you suppose is a better gasket comes under the "If it's not broken, don't fix it!"
I made the mistake years ago and bought a Cloyes adjustable roller cam button timing cover. Because of the thicker cast aluminum they only might clear stock water pumps rear cover. All higher volume improved pumps have wider impellers. So I couldn't even put on my Stewart aluminum water pump. I tried button head allens, I gave up and took my POS Cloyes cover down to the shop and milled off .035 or something and then the button head allens worked.
I would say that the only problem with "Team G" water pumps is the low Gallon Per Minute at lower RPM. I had even made it worse because I had March aluminum 6 inch crank shaft pulley. So I had a friend machine a smaller diameter water pump pulley out of billet aluminum. The plus side of Team G pumps is the ability to not cavitate at higher rpm. Stock pumps depending on the gearing might quit because of cavitation something over 6000 crank shaft rpm. Team G pumps something like 38 GPM as the rpms come up.
I use Stant racing 28-32 pound radiator caps. I never want puking and never have had puking! I run distilled water with an anti-corrosive and polymer cooling product.
They do make water pump spacers to help clear the timing cover as well.. I got away with thicker gaskets myself but just barely. I bought the pump with the cast impeller which is supposed flex less.
582 update- water pump woes!
