VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1937-1945 1938 General

My fax is 630-574-2007.

Brian

Thanks for the data MacHB!

I did the test drive and the cooling system is still overheating. I drove 5 miles and the temperture got to 200 so I stoppped. Nothing happened. waited several hours then drove back and the radiator overflowed about a pint. The entire ride back the radiator was about 190 but as soon as the car stopped the temp went to 212 and overflowed. It seems to me if the cooling system is flowing this should not happen. Is this indicative of some specific cooling system problem?

I'm getting conflicting info on the third brush issue. Some sources say that the third brush is fixed, others it is adjustable. If it is fixed how do I increase the charge?

Thanks,

Brian

If you are reluctant to do the above, maybe have a shop flush the rad. and block and replace the coolant. Are you running the proper mix?? Mac

Looking at the generator on my '39 it appears that the third brush is "fixed"...its adjustable on my '34 as well as the rebuilt generators made for 1929-39.

What temperature thermostat are you running??????
If its a 180 your in the correct heat range which is too warm for comfort in the older cars in the summer.I run a 160 deg. in all of my cars and these leaves a margin for "error" when the hot engine is shut off.

Probably should get some heavy duty two part powdered radiator flush and give it a treatment.

I took the thermostat out and I'm still having the problem. Where do you find the two part powder?

Now I think the pump is the problem. Everytime the car gets hot there is a new squeak that I never heard before. Also the heat problem seems to be getting worse. I think the pump impeller is slipping on the shaft and the problem gets worse as it gets hotter. I'm going to remove the water pump and check it out. The pump only has 90 miles on it.

Brian

The radiator flush was available in most parts stores but I haven't looked for it lately.I have about 10 cans on the shelf and keep one in each car.Over the years I have found it to be the only product that worked.
Was made under two names...Prestone brand in a yellow can and #7 brand in a silver can.The can is cardboard but looks to be metal and both ends open.Cleaner in one end and neutralizer in the other.

I don't envy you taking off the water pump on a 1937-38 as its kind of a do-by-feel project.Sounds like a good place to start..Besides the fan belt squeaking (common with most newer belts) the timing cover seal can squeak when new as well as the water pump seal.Try it with the fan belt off.That will eleminate 2 of the 3.

I have heard of two persons that had overheating problems caused by mouse nests in the radiator.The mice got in there while the car was apart and the radiator hoses were removed.

There's no evidence of a mouse nest but I'll keep an eye out.

Is there a way to adjust the charge rate on a fixed brush generator?

Thanks,

Brian

No-the voltage control does that.When the battery voltage is low it will increase the amp rate untill the battery is fully charged.If the amp rate is set too low (at the volt control) it will not charge enough when the lights and eletrical items are in use.

I think it may be time to install your new voltage control. :)

This is with the new voltage control. The old regulator would stop working when the temperature got hot.

I added oil to all the shocks and they were all near dry. I had rebuilt them and put them back on the car maybe 5 years ago and they have never been used. One problem is I think I put gear oil not hydraulic oil in them. However I did notice a difference in the ride so this winter I may have them rebuilt, if they still leak.

Brian

I'm one of those who had a mouse nest in a stored radiator. A local radiator shop was a big help with my '35; he cleaned it, flushed it and did a flow check. My old core now flows between 15 to 16 gallons per minute on his test machine but in his experience he thought these type of radiators should be closer to 18 or 20gpm. My car runs at 180 while underway but will edge up towards 200 or more while at a long idle. Strongly suggest you have your radiator checked out by a pro.

My parts book shows two water pumps for '38; one with a bushing and another with a ball bearing. You might want to check these for wear or play, possibly a bad bearing causing the squeak when it heats up.

Coach

Early '38's had the bushing type pumps - late the bearing type....after 1939 all Chevrolet replacement pumps were the bearing type and looked like a 1939 -40 pump.

I seem to remember a story in " Old Tractors and the men who love them " by Roger Welsch where he had for a period of time enjoyed eating unshelled peanuts in his shop. After finding clumps of shell material in radiators and gearboxes and the most horrid places, he stopped the practice. Could cats be good for something???? Chevy40

Okay, here's the scoop. I finally got the water pump off and it looks fine. The shaft to impeller connection is good and the sheave to shaft is good also. Therefore the squeak is still a mystery. The inside of the pump is smooth and there was no debris on the surface which leads me to believe that fluid was flowing through the pump.

The lower hose has a wire spring in it and when I disconnected it from the pump I discovered that there was some debris in the hose, some gritty material, and some on the wire spring, what looked like fibrous material like gasket material. The gaskets on the pump look fine and the head gasket is the metal ring type. I may have dropped something in the system that has become shredded by the pump.

Is there a way to force liquid through the engine and radiator in reverse to remove any thing that may have stuck in some of the smaller openings? The over heating problem has progressively gotten worse. Does any of the information I’ve said fit with that scenario?

Thanks,
Brian

very easy but a little messy to do.With the upper and lower hoses removed place the graden hose into the lower hase connection on the readiator.Put full water pressure on and flush the radiator.I hold a rag around the connection to keep the water flowing thru the core.Would do it with the rad. cap on and off.Then flush the same way from the top to the bottom.

For the block remove the thermostat and force water thru from the lower hose connection and the upper.Remove the drain plug at the rear of the block and the temperature gauge in the head.Also force water thru the drain plug and temp. openings.

I would suspect that the core is restricted more than the block as it has only small long passages.The water shoul pass thru the core as fast as the hose can feed it in.The core should feel equally cold in all areas (water temp cold).Flush the heater core also.