VCCA Home Forums Technical - Prewar 1929-1932 1931 Shakedown, coolant foaming

Like Jerry and his 29 I am also trying to work out the bugs on my 31 since it is back on the road. I did a search and it was fun reading the old reply's from Chipper, Gene, Mr.Mack, JYD , and others. After all that I should not have questions but I am slow.

So I believe air is coming past my water pump shaft causing it to foam when the engine is slowed down. I have some water pump grease and coolant coming out of the pump that is visible on the shaft . I did tighten the packing nut with only slight help. I added a ring of packing and it is still foaming when the engine slows coming to a stop.

The engine is not over heating and runs well.

Question # 1 is how tight should I go on the packing nut or where do you stop before you cause problems with the shaft over heating?

Question 2# I noticed a small hole in the radiator inlet pipe, inside the radiator just under the cap. The hole points up towards the cap. Watching it run at idle does not look like it would be a problem. Looks like a rust hole. Could this be causing my problems?

Thanks

Dave

Hello Dave39MD,
When you say coolant and pump grease is appearing on the shaft ahead of the water pump housing, is that the foaming that you are seeing at that location or somewhere else? Try removing the fan belt and wobble the fan/water pump shaft to check for loose play between shaft and bushing. Too much play will continue to work the packing seal and internal coolant will work past and leak. I'd say that you can tighten the packing until you feel resistance in shaft rotation just beginning. Then reinstall fan belt and tension to just snug, not loose-not tight and see how that works. No clue as to the hole under the radiator cap that you see. Is it above coolant level? I would not think that there is air in system, unless low on coolant. edit. Maybe air and coolant are swapping places like Chipper suggests.

Harry, Thanks for the reply. The foaming comes out and around the rad cap. The water pump grease and a slight amount of coolant is coming out from the pump to the shaft and the area below the shaft on the pump.

Dave

If the water pump shaft is galled or too worn new or tight packing may not be enough.

It should leak, just not much. The water is the lubricant. It would be nice if the leak was extremely slow. A drop every 15 minutes or so might be really nice. Sneak up on it. keep making it leak a little less. On my packing nut water pump I can reach under there and it is always damp, but I never see any water on the ground. If the nut is extremely tight and still leaking noticeably the nut is probably bottomed out and it needs more packing. If more packing won't do it, The pump probably needs an overhaul.


I really doubt it could be a problem. If your water pump leaks excessively that is almost certainly the cause. If the water pump isn't leaking excessively, and you are using ethylene glycol coolant, you might need some coolant that foams less (Valvoline/Zerex G-05 is a good choice). It wont compensate for an water pump that leaks air though.

Thanks Chipper and Bloo!

I am not 100% but I think I put a new pump on it when I started this adventure 10 years ago. I do have pumps and shafts here if that turns out to be the problem. What is visible of the shaft does look new.

I put one ring of new packing in and it is tighten up a little past snug. I can't see water leaking but the depressed area under the shaft is wet when I get back from a run, grease coming out of the packing nut on to the shaft. I will run it again this morning and see what happens. I'll find some Zerex G-05 and give that a try as well.

Dave

Ran it mid morning and there was no surge of foam at the usual spots in my test run. When I got back to the shop inside the cap was foamy as was the over flow tube discharge. Water and grease still getting by the packing so I am taking this as a sign to tighten up a little more.

Found the G-05 at NAPA.

Dave

No change today. I did have my laser temp gauge and as soon as I got back I hit the packing nut and it was 142 F same as the stat housing and rad inlet. Do you think this may be reasonable? My thinking is if I have it too tight it would be getting hot so I may have a ways to go in tightening it. A slight amount of grease still easing out at the packing nut and shaft but very little water at this point.

I must not have done anything with this pump because I believe I could get another ring of packing into it.

thanks

Dave

ps This is a fun car to drive, I knew it would be so it kept me going.

Just slow down the leak as much as you possibly can, but don't quite stop it. When you stop it the packing and shaft will burn up fairy quickly. It really is that simple. In the future if it starts leaking more, tighten it more. Great news to hear that it is on the road!

Thanks Bloo

we call it a controlled leak use packing in a lot of industrial pumps in various applications. depending on the application how many drips per second/ minute you need. basically serves as the LUBE for hte packing and shaft. too loose and you loose your fluid, too tight and you burn up shaft/packing. depending on what you are pumping which cost you more

Thanks Jerry.

I guess I am looking for that point where air is not getting past the packing but the shaft stays cool with a slight controlled leak. I still have some foaming. I put better bolts in the repo hose clamps on the bottom hose yesterday just in case it was not tight enough even though I did use a little sealer on the connections.

Trying to do one thing at a time so I know what caused the foaming.

I think my plan is one more test run then a new water pump, then the new antifreeze.

I hope your 29 is progressing

Dave

Hello Dave39MD,
Looking at 'The Filling Station' online catalog with regards to water pump parts for 1931 Chevy:
RW-145 water pump rebuild kit: $169.50
VT-27 water pump grease: $ 17.50
RW-220T water pump packing: $ 3.95
WP-836259 water pump: $ 195.00
To me everything seems pricey so before throwing out or rebuilding your current water pump, maybe you can do some testing with your pump using; Aqua Shield Grease. Look it up and read the description. It does say to use gloves as it clings to most anything.

Just in case you haven't seen this:

https://forums.aaca.org/topic/375509-bloos-not-quite-scientific-antifreeze-foaming-test/

Thanks Harry, I agree on making sure before I change any parts.

Bloo, I re read your AACA test. I do remember reading it but since I never had a foaming issue it did not stick.

It is odd that after I ran the Evapo rust treatment I refilled with anti freeze and I bet it was the same O Reilly's you had a problem with. The first time in 50 or so years of having a foaming problem. I will confirm when back to the shop.

I think I may just try the g 05 and see what that does. Maybe loosen up the packing nut a 1/4 turn to get it a little wet.

Thanks for the time and sharing of the test!

Dave

Thanks Bloo!

I put the Zerex 05 in and ran it hard to my usual turn around spot and ran it hard back. Not even a hint of foam .I did loosened the packing nut a flat and have a hint of water coming out.

Looks like all I need to do is find a top and upholstery shop.

Thanks for everyone's suggestions.

Dave