temp gauge pegging out?

[Burchtree]

I just added a radiator and got my bronco running. I had some seafoam in it so I let it idle for a bit. I noticed that my temp gauge was pegged out, so I shut it off. Of course, that is the only thing working on the dash so I don't know if its reliable. How do I go about seeing if my truck is cooling properly without it overheating?

And forgot -- I had another question. ;D I have power brakes (76), and I bled them, but they like to stick in the "down" position. Any remedies?

 

[jabranovich]

temp.

When vehicle is at temp.you should be able to hold onto upper rad.hose for 3-4 seconds and its hot but not enough to "burn" thats about 180,if your temp.wire going to sender is grounded out anywere it will peg gauge,if no other gauge works there is a resistor on back of dash that if it goes bad every gauge will peg itself.

 

[Burchtree]

Thanks - I took the cap off the radiator and turned the truck on. I saw no movement of the fluid at all. I'm wondering if my water pump is dead. . .

 

[DonsBolt]

you might not see any movement in the coolant till the thermostat opens.

Take the cap off, start the engine, and let it run for a few minutes. You might have air in the system, and if you let it run without the cap for a while it might burp the air out of the system.

 

[big daddy walt]

I would replace the thermostat. If you had the radiator out with no coolant in the system things seem to get rusty and freeze up.

 

[Burchtree]

I did -- replaced the thermostat and hoses before putting in the radiator.

 

[73stallion]

did you burp the cooling system to get all the air out of it?

 

[Burchtree]

Burping it like Donsbolt mentioned, or is there another method?

 

[73stallion]

i kinda have my own method, seems to work pretty well for me. here goes;

without the engine running, pull the temp sensor from the intake. since it's the highest point in the cooling system aside from the radiator, it'll let all the air out of the engine. fill the radiator slowly. when you see water/coolant come out of the sensor hole, replace the sensor. now you have the air out of the engine and you can top off the cooling system.

give that a quick try and see what happens. should only take you about 5 minutes.

 

[76 bronco J]

,,,,,,on the coolant filling.....here's another method to fill without ever starting the motor,,,, by installing a coolant filter or inline fill cap in the upper radiator hose as shown in the pic then making sure the thermostat has a hole in the flange section with a little jiggle pin(lots already have this),,,if the thermostat brand you buy does not have this just drill a tiny hole in the flange section.........for the brakes remember on 76's you have to pull a little pin on the front of the distribution/proportioning valve while bleeding the brakes(you can make a little device to hold the pin out instead of there "special" tool easily),,,for sticking it could be the pistons in the calipers or the sliding hardware ///////// side note EDIT-found one older pic of some of the stuff the coolant filter was catching which included some aluminum shaved bits & pieces from most likely the fabricated AFCO radiator from duff's ,,,, I do have aluminum heads & aluminum waterpump so they are a posiblity also for the aluminum bits(some were big ,I need to find those pics),,,,,there is never anything in it now & these pics were taken when everything was brand new not rebuilt.....I not sure if this little stuff floating around matters much ,but maybe the coolant filter isn't a bad idea to incorporate into the cooling system,,,,,this brand is TEFBA

 

[Burchtree]

Okay - when I took the temp sensor off the intake, the water/antifreeze came out and my radiator fluid went down, but it didn't seem to "burb" any air. So . . . what does that mean?

 

[Burchtree]

BTW -- fixed the return on the brakes. The vertical bolt on the bracket was tight as a drum.

 

[Burchtree]

I'm stuck here -- any other ideas on checking to see if this water pump is working? How long can I run the truck without damage if it isn't working?

 

[Amac70]

i would buy a new gauge. How long does it take to peg the guage? i've never had a water pump stop working. They usually start leaking when they go bad. I would let it warm up again and give it enough time for the thermostat to open up.

 

[JeepGuy]

You could always buy a cheap manual temp gauage, put it in and then run the engine to see where it's at. easy job and not too expensive.

I've done similar filling styles as 73 stallion and it works pretty good. Another way is to leave the radiator cap in the pressure release position(usually quarter turn before off), run the engine. That will give the air somewhere to get out but you still stand the chance of a bubble on the intake (possible, just throwing it out there). Make sure your somewhere you dont mind some spill over from the fluid running by.

 

[slider58]

Isn't there a voltage regulator behind the dash that when it goes bad, it causes the gauges to peg out?

 

[Burchtree]

I know it takes less than a minute. I turned it on the other day and it didn't peg out immediately but I got out and checked the engine for "burping," and checked again and it was pegged. I'll try that out today and see how long it takes. I think I'll check out that "resistor" on the back of the gauge.

 

[Burchtree]

Hey, I tried organizing my shop (looks worse now than when I started ), but I did find my voltmeter. ;D I took the voltage regulator off, and am replacing it with a new one tonight. Is there a way to test the old one before spending 38 on a new one?

Thanks a bunch for all the help -- I owe you all cold beverages of your choice.

 

[Amac70]

almost all autoparts stores can test a voltage regulator for free.

 

[Burchtree]

well damn -- I guess I'll take it back and have them check it for me. Thanks for the tip!