'40 Gas, Oil pressure Gauges
 

Well, I finally got the "40 running again !! Now, I'm trying to tie up loose ends. How do you check to see whether or not your gauges are not working? I did the CVR route and only the Temp and Volt gauge is working. I mistakenly installed a 80lb oil pressure sender, using a 40lb pump. Can this be remedied by changing senders? Also, I might add that the gas and oil pressure were registering, but suddenly quit while driving down the road. I don't know what to check or do at this point.
P.S.
This site has been a great source of information in this rebuild! A lot of good people with similar interests !!!!

Re: '40 Gas, Oil pressure Gauges
 

I like the old school gauges but temp gauge repair sounds tough so I am trying SW with electro first time. Can’t easily find lower temp 0-200 deg old timely that really work anymore. But for oil so easy to use tube/hose and any gauge. For fuel pressure, I understand it’s hard to find 0-10 # gauge for normal flathead feed.

Re: '40 Gas, Oil pressure Gauges
 

The gauges work by providing 6v to the gauge. The gauge is then connected to the sensor, which acts like a variable ground. If two gauges stop working, I would guess the issues is at the power input to the gauges.

The gauge needs to be matched to the sending unit for oil pressure.

Re: '40 Gas, Oil pressure Gauges
 

I have not been able to find a 40 lb. oil pressure sender. I put a direct reading gauge on my 40 so now I know that my gauge reads half of what the pressure is. I can live with that

Re: '40 Gas, Oil pressure Gauges
 

Correct me; I haven't yet heard of a 40# sender or oil pump? It has always been
a 50# or 80# sender= look at your oil gauge if it has 30 in the middle its 80# If its a

lower number which I forgot will be 50# sender..

Re: '40 Gas, Oil pressure Gauges
 

Sorry fella's, I installed a 80lb sender with a 50lb pump. Can changing the sending unit to a 50lb one fix this problem ? I also used "19Fordy"s diagram with a Ron Fransis CRV-1 reducer for the voltage drop. That replaced one of the "chopper" drop that I had installed a number of years ago. Now I'm wondering if I had the "chopper" one installed incorrectly and damaged the gauges. Also, the "chopper" was installed when the fuel and oil quit working.
Again, thanks for the input.

Re: '40 Gas, Oil pressure Gauges
 

So, I'm assuming your converted to 12v? Second question, what oil pressures are you seeing? What engine are we dealing with? The pump rated pressure doesn't mean much, the pressure relief determines the system pressure. The pump rating is more about volume.

Re: '40 Gas, Oil pressure Gauges
 

Yes, I converted to 12V many years ago before this last rebuild. I am seeing 0 oil pressure on the gauge at this time, which was working when we started the engine up(the gas gauge was working too). The engine is an 8BA bored .040 over, Isky Max-1 cam, running 2 Stromberg 97's on an Offy Super dual intake with Red's headers. When we built the engine, I installed a 50LB pump.

Re: '40 Gas, Oil pressure Gauges
 

Could I ask your rationale behind putting an early (50 lb) pump in an 8BA? Usually, it's the other way around.

Re: '40 Gas, Oil pressure Gauges
 

Tubman,
I think my rationale came from this site, in that I was not building a high performance engine and did need the high volume oil pump.

Re: '40 Gas, Oil pressure Gauges
 

A 80# pump is the standard pump in the 8BA.

Re: '40 Gas, Oil pressure Gauges
 

Terry,Oh, and others;

I purchased the pump from Speedway. It was a Melling M19 Std volume oil pump. I figured I did not need a high volume, high pressure pump since I was only building a "warmed" street engine. I guess in my great ignorance of flatheads I chose the wrong pump. Right now, I'm really looking for answers and help to my questions about the gauges, otherwise, I'll just replace the original panel with something that all the gauges will work.

Thanks in advance to all helpful suggestions thus far. I'm checking them out.

Re: '40 Gas, Oil pressure Gauges
 

As long as you have the correct pick-up for the pump and the screen is the correct distance from the oil pan, it should be fine.

Did you see the attachment to post #3 on how to check the gauges? Is there a different question you are asking? Maybe I'm not understanding what you question is.

Re: '40 Gas, Oil pressure Gauges
 

Yes, changing to a 50# sender that matches your gauge will work just fine.



Terry

Re: '40 Gas, Oil pressure Gauges
 

JSeery;
Yes I have the correct for the pump installed. I saw your attachment to post #3 and am currently trying to work thru checking the gauges to see if possibly I damaged them. Thank for all that good information.

Re: '40 Gas, Oil pressure Gauges
 

Correct me if I am wrong, but you shouldn't need to connect the CVR to the volt meter

Re: '40 Gas, Oil pressure Gauges
 

paul2748;

I wired the "Batt" gauge per "19Fordy's" diagram and it works like a charm. I wired from my fuse block (3amp fuse) thru the resistor to the gauge.

Re: '40 Gas, Oil pressure Gauges
 

Read this thread about making 1940 BATT gauge read accurately when converting to 12V.
https://www.fordbarn.com/forum/showt...ford+voltmeter

Re: '40 Gas, Oil pressure Gauges
 

Once in a while my gauges will quit while going down the road. Jiggle the ignition switch or put a little pressure toward the off position and they are happy again.

Re: '40 Gas, Oil pressure Gauges
 

Well, I finally figured out the problem with my fuel and oil pressure factory gauges. I was under the '40 yesterday hooking up the return oil line for the third time (after replacing the oil sender with the 50# unit), looked up to see a wire that had become disconnected. Wondered, could this be the problem on the nonworking fuel gauge ? Reconnected the wires, crawled out from under the car, reconnected the battery, fired the '40 up and had working oil pressure and fuel gauges !!! Again, many thanks for all the good information and help from the people on this site.
Guess I need to look for the real simple solutions first !!!