I have a '95 F150, 5.8 engine. I'm losing various fluids, but not sure where they're going. I know about the oil leak, which I suspect is a rear main seal. Not looking forward to fixing that! But- I'm losing coolant fairly quickly, and I don't see any leaks. I replaced the hoses, and a metal tube that had sprung 3 separate leaks. It seemed OK for a while, but it's losing coolant again. I can't see any leaks, hot or cold. Head gasket? The exhaust doesn't smell like antifreeze, but I don't know where else it could be going. No water in the motor oil. Likewise, I'm going through brake fluid pretty fast. Again, no visible leaks. The wheel cylinders and calipers are bone dry. No leaks on any of the brake lines that I can see. Gotta be going somewhere. The brake pedal is good and firm, and doesn't sink no matter how hard I press. What am I missing here? Thanks for any suggestions!

 

When you say you replaced a metal tube, do you mean the one that the engine coolant temperature sensor is threaded into? That area and the thermostat housing is a likely place for leaks, along with coolant hose band clamps that need some tightening.
I don't know if a '95 has the same master cylinder as an '88, but my '88 was leaking at the piston stop screw labeled number 6 in this drawing.

It's a slotted head screw, so I slowly tightened it, maybe 1/8 turn a day, for several days, and it stopped leaking.
The other brake fluid leaks I had were one at one of the front caliper banjo fittings, and another at a rear drum brake cylinder.
The banjo fitting leak was caused by a flaw in a rebuilt brake caliper that I bought.

 

Do you have an oil cooler? My 302 is leaking oil where the hoses attach to the filter.

What condition is the coolant line under the throttle body? Mine dried out and started loosing coolant under pressure, until it fully split.

 

On the brake fluid because it has a common tank and you said you have checked the wheel cly and calipers and ALL LINES? and were dry inside the cab pull back the rug and padding from the firewall where the master bolts up and see if it is wet.
The master seal goes bad on the piston and fluid leaks down the inside of the firewall and the rug & pad act like a sponge and soak up the brake fluid. replace the master.

Get your self a cooling system pressure tester, HF has them pretty cheaply.
For testing I would fill the system with water, anti freeze is not cheap. Your cap is marked in PSI pump the leak tester up to the caps marking.
If the system holds the needle should not drop, if it dose you have a leak and you can now start to look for water dripping on the ground, if lucky, and follow it till you find the cause for the leak.
If it leaks down pretty fast you should be able to find it quickly if slowly it may take a bit of time before you see it on the ground.

Dont over look the heater core leaking. Again inside the cab pull back the carpet & padding on the passenger side floor and firewall. It is not un-common for the core to leak and like the brake fluid the rug soak it up.
Because you are from where it is warm, right now damn hot! you may not use the heat but a sign of a bad core is a sweet smell of anti-freeze inside and the inside windows fog up and you cant wipe it clear, kind of a oily mess, when it is cold or rainy.
Dave ----

 

Hmmm... I have a rubber floor mat, but it probably has padding under it. When I replaced the coolant hoses, I did the radiator hoses, heater hoses, and a metal tube near the throttle body and the associated small hoses attached to it. There is a fitting that screws into the intake manifold that was corroded beyond repair as well. As for the brakes, everything around the master cylinder is dry as well, so I guess it could be leaking out the back of the MC and down to the floor. Might find some interesting stuff under that floor mat!

 

Here's my observation of the "loosing coolant, stinks, no puddles/drips" that has been confirmed as near universal for 5.8s/5.0s:



The timing cover passage leaks, cooks off.

 

Pull the vacuum hose of the brake booster and see if it has brake fluid in it. Usually you would see smoke if the engine is sucking brake fluid.
My 351 looses coolant, same as you no leaks, must be going some where. My old 351w truck did the same thing.

 

Oh crap you are right what the he11 was I thinking of fluid leaking inside the truck with power brakes
Thing is if not enough fluid has been leaked into the booster you may not see it or get pulled into the motor and smoke.
If you have a boar scope you can pull the vacuum hose & check valve and look down inside for fluid.
Dave ----

 

you could try snugging up the nuts/bolts, in @Scndsin picture, mine had/has same leak now, 5yrs later, when I did water pump. and 3 studs broke off.

 

my truck had this same leak when I bought it. Replaced the water pump and gasket {thank the Lord no bolts broke on me} and has been dry ever since.

 

I'm not seeing that leak on mine. I'm going to pressure test the system as soon as this insane heat lets up.

 

did someone say something about losing their fluids???

t

 

Ahhh, the good old days of duck & cover.