Can't seem to bleed the brand new calipers. The level doesn't change in the master cylinder at all. Sometimes there's a metallic clunk when pushing down on the pedal. About the most interesting thing that does happen is the mini geyser in the middle of the rear (smaller) reservoir. I think the biggest problem with bleeding the new calipers is the gunk/crap in the reservoir's that I just can't get rid of with a turkey baster.

Someone added a trailer harness + brake (I think anyway) to this at some point. It's nastially hacked into the tail light harness and has a brake fluid line from the box in-cab to what I think is a block on the rear line. The lever moves when I'm pumping the brakes, not a lot but some. Why would the "trailer" brake activate the drum brakes, are they just not used enough in the first place or does it really help? Can I remove it? I do plan on using this to tow in the future so I'd kinda like to keep it but I think the harness for the box in the cab is too far gone to reuse any wires coming out of it. Oh, is that nice 4pin black plug on the end of the taillight harness availble seperatly like the bulb sockets? There's about 1/2in of unhacked wire on it (not enough to splice more wire onto) and I'd like to rebuild the rear harness.

I went ahead and had NAPA order a new power booster and master cylinder. Should I contact 'em tomorrow and try to change it to one of the two or is both good?
Won't get it until Tuesday or Wednesday next week so I'll spend the time attempting to work on the wiring mess.

 

The hydraulic trailer brake system was an antiquated design that is no longer in use, and is unsafe. You do want to remove all the traces of the hydraulic trailer brakes. Repair where necessary.

The metallic clunk sounds like the booster's push rod was adjusted incorrectly. I bet you have excessive pedal travel as well.

The geyser means you have air in the rear portion.

If the master cylinder is caked with goop, remove and clean/replace and drain every drop of old brake fluid. Since you ordered a new M/C and booster, just discard the old ones. I'd blow the lines with compressed air to remove anything that may be stuck in there.

If you plan to tow, buy a new system - electric trailer controller, wiring harness, etc.

 

So removing the trailer brake controller is as straight forward as it appears to be? That's good, surprises are annoying.

Hmm... air in the rear portion. The trailer brake line appeared to be leaking fluid, a very small amount, just enough to notice, but would that cause it?
If not I plan on doing rear shoes, wheel cylinders and a drum hardware kit anyway once I get it in a better place to put new leaf's in the rear. I'm trying to cut down on the number of times I have remove 8 lug nuts per wheel, especially because I had to replace about 1/2 of 'em and they're a different hex size then stock.

 

Sure. I don't know what exactly it has, but just remove everything and reset it to factory specs.

That could be the source...maybe. That's one source, you'll have to find out if there are more.

 

If it's one of the old KH trailer brakes - and it seems like it is if it is hydraulic then it IS factory.

Removal of these is pretty straight forward - yet sometimes tricky to get the hard line through the firewall and out of the truck

 

I have a hydraulic trailer brake system too and I'd like to know more. Mine has the brake line tapped into a 't' in the rear brake portion of the master cylinder and the controller sends an electronic signal to the rear pigtail. Everything works fine so I didn't want to mess with it. Can anyone elaborate as to what exactly makes it unsafe?

 

It is factory? Since when?

Ford did not offer any trailer brake controller on any 1973/79 F100/350.

Happen to have the 1973/79 Ford Light Truck Parts Catalog handy? You can spend an hour, a week, a month, or an entire year looking thru it for this controller. You wont find diddly.

Ford only offered, on Trailer Specials only, the wiring harness for the trailer lights that plugged into the taillamp loom.

No gooseneck hitches were offered either. The only thing Ford offered were two different sized trailer hitch ***** that mounted on the step bumper.

If a 1970's truck has a trailer brake controller, it was dealer installed using aftermarket parts, or it was installed by a place that sold campers, or possibly by U-Haul.

 

Dealer installed then??? *edit* - you changed your post to verify this

Why has EVERY trailer brake controller I have ever seen on any of these been the same? I've had 5 on trucks I have owned. Every pic I have ever seen that has a trailer brake has the same one as well.

Gotta be more than a coincidence...

 

OK, find me a part number or any reference to a trailer brake controller in the '73/79 Ford truck parts catalog or in any 1973/79 Ford factory shop manual.

Happy hunting!

btw: How old were you when these trucks were new? How many have you bought new?

I was a Ford partsman for 35 years (1962/97), right here in LA LA Land.

If Ford offered a FACTORY trailer brake controller for any 1970's truck, Econoline, Bronco...whatever, I would know about it.

 

No thanks.

I'll leave the part number hunting to you as it is in no way my thing. I know you do a lot for the people here in finding part numbers - but USUALLY (yes you have helped me in the past) that stuff doesn't mean a rat's a$$ to me.

I'll put the best part for the job on my truck - whether it was made for ford of fiat. I'm NO WHERE NEAR the guy that cares about period correct or correct part numbers, etc...

Also - from what I've seen it really doesn't matter to me what the parts books say. Ford always seemed to put whatever they want wherever they want whether the parts books said it should be there or not.

And, as I said - must be dealer installed - which you backed up when you edited your post.

I just think it's funny that the ONLY style of controller I have EVER seen in one of these trucks is the same.


EDIT - you added to yours - so I'll add to mine.
Try this one on for size... I was NOT BORN when these trucks were new. So yeah - NEVER bought any new. Yes you know more than me about parts on these trucks. Yes I made a mistake about factory vs. dealer installed.

Does any of this mean I love these trucks any less than you do????

Not one bit.

You keep your part # correct trucks and I'll keep my real world work horses with fancy fab. Not sure which one would out perform the other...

 

Ppl that say all parts catalogs are wrong do not have any parts catalogs, nor do they have any Ford parts experience of any kind.

Since they have none of this, how do they know that all parts catalogs are wrong?

They don't.

One former member made this parts catalog wrong BS comment when I was helping another member find parking brake cables.

Then the guy had the unmitigated gall to ask me for part numbers (in a P/M) for some body mouldings.

I told him: "Sorry, I can't help you, all Ford parts catalogs are wrong!"

 

I'm guessing that if the majority of these that have the same trailer brake (sounds like a stupid name for a lever that activates the rear brakes to me but I dunno what else to call it) model it must have been the best/cheapest/available at the time.

Not that it matters but my '78 is 9 years older then me and I've already learned that NumberDummy isn't wrong