weird overheating question

[Ohio Bronco 21]

This is a new one.
Dads 69 Bronco is overheating and brakes also over heating after about 45 min of running her. Its a 302, headers, 4 core radiator, power brake booster/disk. The engine gets up over 215 after some time, when checking the engine compartment the Brake booster is really hot as is the master cylinder and brake lines somewhat warm, almost boiling the brake fluid in the master. The Engine is really hot too.

The brakes are not hanging up and I checked the booster pushrod to the master cylinder, It was adjusted a little out so I adjusted it in a little. I thought it may of been slightly causing the brakes to rub when the engine was running and vacum up. The longer you ran it the hotter the brakes would get and the lines and finally the booster/master. I thought this would also of caused the engine to overheat due to drag on it.
Well, doing the adjustment on the brake push rod may of helped but He still has the same problem. I checked the lines and while they are somewhat close to the headers they do not touch and the lines themselves are not heated up much.

What could be causing the brake system to heat up so much and the engine also? Thanks for any help or ideas.

 

[Broncobowsher]

Engine compartment heat is probably heating the master cylinder and booster. IF the brakes were dragging then the rotors and pads would be getting hot, not the master cylinder

So the engine gets warm "after some time", OK, some time doing what? Some time on the highway, some time idling? Do you have a fan shroud?

 

[Socal Tom]

FLush and fill the brake fluid. It absorbs water and that can cause it to boil much faster than pure brake fluid. If it has a lot of water in it then it could be expanding due to engine heat, and then applying the brakes making the problem worse.
Tom

 

[oleguy74]

as for the engine ,flush system and refill with 50-50 mix.

 

[Ohio Bronco 21]

The driving I spoke of was freeway driving the first time this happened and then around town (traffic lights etc) the second time. The fluid in the system is new.

 

[broncnaz]

What conditon is the cooling system in? ie how old is the radiator/ last time it was flushed? As was posted your brake system is just getting heat soak there is no way for the vacuum booster or MC to build its own heat. I wouldnt worry much about it if the lines near the headers are not that hot then its not a problem.
Is the engine spewing out water? if not could be the water temp sender is going bad. Might also want to put in a new 190 degree T stat. There are a lot of other things that could cause the engine to run hot a lean or rich condition, wrong timing, ect.

 

[FASTERDAMITT]

Mine runs from 195 to 230. I understand they're not overheating untill 240-260.

 

[Ohio Bronco 21]

Thanks guys. I do believe the timming is advanced just a bit. I will tell dad to retard it a little. He put in a cooler thermostat today and flushed the engine.

 

[taipeichris]

Hi,

I had a similar problem with my rebuilt motor over heating. First, has the motor been rebuilt recently? Sometimes if the block is too thin, the motor will run hot. For me I thought about running a cooler thermostat but I didn't want my motor to run too cold.

BUT I doubt this is your problem.

I agree, flush the motor, heater core, and radiator separately.

First drain and collect your old coolant to recycle.

Second, I got a bass hose fitting from a hardware store, same size as my heater hose with it ribbed on one side to insert into the heater hose then clamped it down with a hose clamp.

On the other side of the brass fitting it's threaded so I could attach my garden hose and really let the water flow at a high volume.

I flushed the heater core first, motor from top to bottom, then the radiator also from top to bottom.

You would be amazed as to how much rusty little metal flakes were in my system! If only those were gold flakes!

After all said and done, I put my hoses back together and then added an inline filter on the inlet side of my heater core.

I used the mating brass fitting with a small brass screen as a filter. I checked this filter again after about two weeks and it was full. Eventually I got 95% of the rusty metal flakes out.

Make sure you refill your system with new coolant and distilled water. Distilled water is suppose to be mineral free and will run much cooler then just normal tap water.

I can email photos to whom ever wants to post them.

Good luck!

Chris

 

[2ndone]

Could be your rod isn'nt adjusted properly, while running it will slowly build brake pressure causing your brakes to start setting,causing engine to pull harder, that rod has a specific adjustment according to manual. Mine was out of adjustment and the brakes would start setting themselves while driving.

 

[Ohio Bronco 21]

I set the rod back in some, it had been a little out. The preassure had indeed been building up. Engine still runs somewhat hot, I am going to have my dad flush the whole system completely however.

 

[blubuckaroo]

Make sure you refill your system with new coolant and distilled water. Distilled water is suppose to be mineral free and will run much cooler then just normal tap water.

I've never seen a garage use distilled water or a part store sell it. I havn't even seen that recomended in any manual. I may get an arguement from this but unless you've got really crummy water, I'd use the stuff from the garden hose. Save the distilled water for batteries.

 

[old number 8]

To get an idea if your radiator is getting plugged, run it till it's hot. Shut it off, then run your hand along the radiator core, top to bottom and side to side. If there are cold spots, those core's are plugged.

 

[broncnaz]

Make sure you refill your system with new coolant and distilled water. Distilled water is suppose to be mineral free and will run much cooler then just normal tap water.

I've never seen a garage use distilled water or a part store sell it. I havn't even seen that recomended in any manual. I may get an arguement from this but unless you've got really crummy water, I'd use the stuff from the garden hose. Save the distilled water for batteries.

Why would they sell it or use it there goal is to sell more parts or fix more vehicles. Yes plain tap water works fine but what ever minerals you can keep out of your system the better. distilled water is pretty cheap its not like your breaking the band by using it. A lot of repair manuals dont tell you to use distilled water in a battery either. I try to use distilled water but as you've pointed out the graden hose is there and easy.

 

[Socal Tom]

As far as I know distilled water doesn't run cooler, but it does extend the life of your radiator and battery.
What happens in a radiator is when the tap water gets hot it can no longer carry to minerals so they stick to the surfaces in the cooling system. Eventually this leads to a coating of calcium and magnisium that doesn't transmit heat very well.

In a battery it similar, except during the charge-discharge cycle, those calcium and magnisium atoms stick to the plates in the battery and where ever they are deposited, that section of the plate is ruined. If you continually use tap water to fill a battery you destroy the battery. It wouldn't surprise me to find that just having those minerals in the battery water lowers the voltage as well.
Tom