So I recently got a 1978 f150 4x4 with an automatic trans and a 400M mill. 111K miles. All stock with a 2bbl and everything intact.

several issues...

1) So I got this from a kid who had it for about a month. Looking around I found tranny fluid in the master cyl, and the gasket for that was like 2X too big as well!
Will the tranny fluid have damaged the brake hose rubber?

2) I checked the oil and it looked clean and kosher, and the truck does not overheat, but when I openend the radiator the water was white... Not brownish and foamy... just white like you rinsed off a paintbrush. It does not smell like oil either, it smells like windshield wiper fluid... might this cause the water to turn white?

3) the truck had a tuneup recently (new wires and cap) but it has a crappy rough idle. as soon as you pull it out of idle it smooths out nicely (pull lit up to about 800-900 rpm). It has no stumbling or other run-ablity issues, it will pull up hillls just fine and all that, but has a crappy idle.
Pulled the plugs and they look to all be burning well. no oil burning. or fouling.

I am going to go through and give a compression test and check any vacuum lines, but thought I would post here for some ideas first.

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Might just need to adjust the idle mixture.

 

Agree first step on idle the carb is adjusting mixture. A check of ignition timing would be a good idea also.

For the cooling system a really good flush with lots of water is in order. You can get adaptors that allow you to hook up a water hose to the water neck with T stat removed and really flush the block. Its also easy to make and adaptor with PVC and plumbing fittings. Then re-fill with 50/50 and watch it. PS... hose flush the heater circuit as well and the radiator.

For the brakes... boy that sounds like a mess but it will just force you to do some necessary maintenance now instead of later. I'm not an expert, but I'd question any rubber parts including potentially seals in the master cylinder and wheel cylinders that got exposed to oil... plus any that are 35 years old. I'd start with a new master and new flex hoses. I just did this on a '78 F250 with 400M as preventative maintenance. I'd do the master first then run several quarts of fresh brake fluid through to flush it before putting on the new flex lines. New rear wheel cylinders also. Personally if the calipers were OK to start with, I'd flush them well with brake fluid and try without replacement. I don't believe they have rubber pressure seals. I used Autozone stuff on mine; cost was reasonable (new master $40) and so far its working great.

When you pull the flex hoses you will be really lucky to get the old steel lines off in one piece even with plenty of penetrating oil. Likley one or more are seized and will twist the line off. Mine were. I got a coil of brake line and extra tube nuts and replaced the hard lines behind the cab and feeding the front calipers. Another option is to order up a set of replacement hard lines from Inline Tube; they will have the flex lines also. I kinda wish I did that myself but I'm sure my hand bent replacements will work fine.

Good luck!

 

Did a comp test, they are all 150-155 psi.

adjusted the idle screws and it didn't make it any better...

It runs like it is misfiring. If I rev it, it smooths out (but you can feel some slight roughness, but it is greatly reduced).

It feels like it is just on the edge of stalling (it is idled up enough) but the way it runs you always wonder if its going to die on you when you are sitting at a light.

Checked the timing and I think it is correct (or very close) I will check it closer tomorrow.

what are the symptoms of a slipped timing chain? would it be like this?

it also has all the smog stuff still on it. could anything fail and cause this type of issue?

 

Before you flush the brake system like Blue and White said I would remove all the current fluid from the master cyl. You might get lucky and all the PO did was to top off the fluid level.

 

If you still have alll of the smog stuff, check all of the many vacuum lines for cracks or wrong connections. The thermal vacuum switches could be the problem. Mine failed smog at idle and wouldn't idle at all when set to 2 turns out on the mixture screws. Bad vacuum switch.

 

I had that problem with my truck when I first got it. The problem ended up being the fuel filter was full of rust.

 

Disconnect the vaccume line to the EGR valve and plug it. Take another piece of vaccume line and connect it to the EGR, make sure it's long enough so you can reach it beside the truck. Start the motor and suck on the vaccume line that's hooked to the EGR. That will force it closed. See if that makes a difference.

I had the same symptoms as you, it turned out the spring in the EGR was broken and wouldn't force it closed causing crappy idle. Replaced the valve and it idles perfect now.

 

Instead of going through gobs of brake fluid, I've disconnected the hard lines and hoses and used brake cleaner in an aerosol can followed by compressed air to blow and dry out the system. Ain't that what the lil straw is for?

Sounds like your rig is a winner...I'd change ALL the fluids and lube- coolant, oil, brake, axles, T-case, tranny, and filters to establish a known baseline

The white coolant could be a result of running vinegar through the system to break down calcified deposits. How do your coolant tubes look?

2x with a possible EGR, vacuum switches, and vacuum hose issues.

 

Something else, use a pair of vice-grips to pinch off the vac. line going to your brake booster and see if idle changes. Mine was leaking and causing rough idle. Booster replaced and idle is smooth. Assuming that you have a vacuum gauge(they are inexpensive an a must have)get a reading from a port on your intake, to me a steady needle is more important than a number but mid teens to low twenties is fine.
Stinky

 

Good idea, I might just do that instead of all that fluid.
on the good side they seemed to have only used the tranny fluid on the front brakes...
On the bad side it seems they added brake fluid to the tranny...

they system does look very very clean... all brassy and shiny...

how should I go about testing those? there are ****tons of little round units in the middle of all these vac lines, not sure what they do or how to make sure they are working...

Also I have this emissions thing that is near the back of the engine to the passingers side valve cover that is black, has a ton of hoses to it and makes noise when it is connected to the air cleaner lid???

 

I did pinch off that line and it had no noticeable difference.

I do have a gauge and it is bouncing about wildly at idle (between 15 and 18ish)

not sure if I was on an intake runner or not, I just pulled a line off the vac canister real quick (not sure if I even had a good connection.) I will try for another reading tomorrow.

I had good compression from all cyls, so I don't think it is a bad valve... but I don't know. Would a slipped or streached timing chain cause thes issues?

 

Would a slipped or streached timing chain cause thes issues?[/quote]

You can check by removing dist. cap so you can watch the rotor while rocking the crank back and forth, might be easier with spark plugs out, watch as you change directions and you should see if there is slack in the timing chain, rotor should move as you move the crank with no delay. this works for me!

 

Ok, So I tested the EGR and found nothing to be wrong with it... It opened and closed and made it die when I opened it at idle...

Now I checked the slack on the timing chain and found that I could move the pulley about a 1/2 inch before the roter moved.

I also found the timing is about 20-22 at idle... So I think that is where the issue lies... however, the dist is stuck in the intake and I cannot adjust the timing! I sprayed some pb blaster and wd 40 on the bad boy, but any other ideas on how to get er loose?

 

Help?........