Okay, so I bought that 1985 F350 cab/chassis I was looking at.

Here she is:



A couple things I have to deal with:

First, I'm guessing she has a flat spot on the starter, so maybe one time out of ten, instead of the engine firing up, all I get is the solenoid clicking mockingly at me. No big deal, just annoying. I'll look at the starter this weekend.

Second, sometimes the brake warning light stays on for a couple minutes after I start the engine, but goes off after maybe two minutes. The brakes seem fine, so I'm guessing a faulty connection rather than an actual leak or problem with the system. We'll check on that as well.

Finally, my fuel gauge is forever stuck on "E"... even though the tank is full. Don't really know how to get at the sending unit without a) dropping the tank (ugh) or b) taking off the flatbed (bigger ugh), so I'm stuck keeping careful records of odometer readings (currently 45,122) and just filling the tank ever 200 miles or so.

That's another thing: I have no idea what the capacity of the tank is. It's about four feet long and sits amidships between the chassis beams, nearly a foot high at the rear end.

Here's as good a picture I was able to take.



Any ideas what the capacity might be? I've heard guesses between 28 and 40 gallons. Which would be nice, if it's true... but I tend to doubt it.

Any other insight on the other three issues I mentioned above would be great, too.

Thanks!

 

Could also be the switch in the parking brake (makes the light come on when the pedal
is depressed).

This is another common problem, the wires in the mechanical sending unit get worn
through and frayed. Drop your tank, remove your sending unit, open it up (remove the
triangular metal cover) and look inside, it'll be the cause of your problem.

Before you do that, though, ground out the wire at the sending unit that goes to the
gauge; the gauge should peg out in one direction or another (I forget which). This just
verifies the dash gauge works.

Most gassers had 19 gal, some (shortbeds?) had 17. No idea about diesels but I'd
imagine it'd be the same.

-ct

 

19 gal front and i am told 15 in the rear but i'm thinking 20+

As for the fuel gauge, very common on these trucks to read empty. My 86 i only get about 25 miles on the tank and it goes to E. another comon problem is the pickup tube breaks of and you cant get all the fuel out(runs out of fuel when there is actually half a tank left).

PArking brake may just have a loose connection

 

19 gallon in the rear, but some people retro fit larger tanks in the back.

 

If its still got the manual you can check it for the fuel tank sizes.

 

That's one nice truck you got there!!! Now on your questions:

1) mine does the same, I just put her in gear then back in park, and she fires up. Annoying, especially if you have a girl with you, but not the end of the world. I'm thinking tho, the flat spot is on the flexplate, and not the starter.

2) I'm willing to bet your vacuum pump is on its way out - the brake warning light on these trucks gets triggered by the proportioning valve, the parking brake pedal, and (this is diesel-specific) a low-vacuum switch. Basically the truck uses vacuum booster, but the diesel engine makes very little vacuum, so there is a vacuum pump installed on the engine (passenger-side, right below the alternator, driven by a very short belt off the alternator) and that's what operates the brakes, the HVAC system on factory-A/C trucks, and the C6 transmission on the automatic trucks. Vacuum pumps wear with mileage and age, when they fail they usually still make enough vacuum to operate the HVAC and the trans, but you will lose power brake assist. My vacuum pump failed a while back and I converted my truck to hydroboost, but I still needed some vacuum source for my HVAC, so I just left it on and it took it several minutes of driving at engine speeds over 1500 rpms before it builds up enough vacuum that I could switch between different vents on the dash. Your situation ain't quite as bad yet, but keep an eye on it, as stopping a one of these trucks without the brake booster while possible is definitely something you can live without experiencing.

3) gauge usually sinks to "E" cause the float in the tank develops pinhole leaks and fills up with fuel. Very very common issue with diesel trucks, you'll have to drop the tank to inspect the sending unit. Be aware that a float by itself is not available, you are supposed to buy the whole sending unit for about $200. In reality, you can put about any float of suitable size in there, and it will work, we did this to my buddy's '86 F250's front tank. Your tank should be a 19-gallon tank, and yes they are pretty darn long.

By the way, I'm not sure how much you know about the diesel-specific side of these trucks, but the glowplugs system on your '85 suck big time - plugs themselves are pretty awesome, and so is the relay for them, the problem is in the controller that likes to fail in engaged position and thus fry the plugs. Many people just disconnect the controller and install a manual switch in its place and count seconds when operating it (glow time for the plugs is 10 seconds or less), others upgrade to the much more reliable solid-state system that can be found on the '87-'94 trucks. So keep an eye on the "glowplugs" light, if it stays lit for much longer than 10 seconds, or it don't come on at all, you got a problem.

Also, we have a sub-forum here that is designed specifically for these diesel-powered trucks, here it is:
Pre-Power Stroke Diesel (7.3L IDI & 6.9L) - Ford Truck Enthusiasts Forums

 

Hey, thanks!

Hmm. All right, I'll check that out as well.


Well, first off, it's a manual tranny, so I guess no vacuum is being used by the transmission. Second, the AC doesn't appear to be working, which could be a symptom of its own. Finally, a peek under the hood shows that the master cylinder is a lot newer than the rest of the engine, so somebody must have tried to deal with this in the past. I'll look into everything you mentioned. Thanks.


That's what I thought. Looks like I'm gonna have to drop that tank after all. Taking off the flatbed to get at a fiddly little float isn't how I want to spend my day.

Okay, I've just pulled out the manual, which says that the standard tank is 20 gallons and the auxiliary is 19 gallons. But all I've got is the one midship tank. So... until I find out otherwise (by either measuring the dimensions of tank more accurately, or else just draining it), I'll assume that it's 19 gallons.

Still learning. I've been studying the Chilton repair manual, and I've ordered a set of the Ford shop manuals. Plus my stepdad is a diesel mechanic, so I've been picking up some tips from him.

You know, it's funny you should mention that, because I have noticed that the glow plugs light comes on for a few seconds once in a while after the engine is started, or stays on for a bit longer than ten seconds. I was indeed thinking about putting in a manual control switch, and this clinched it for me. Thanks.

Yup. I've been lurking there since I joined this site. I'm sure I'll be posting there once work begins in earnest on this truck.

I notice you're on Diesel Stop and Oilburners, too (I recognized the cat shark avatar), so I'll see ya around there, too.

 

Oooh, that's good to know. I'll definitely try that before dropping the tank. Thanks!

 

Same here, but I spend most of my time here and at OB...TDS is slowing down alittle.

So are you new to all those sites? I have the same username in all 3 except this one is f250 not F350 like the others (joined FTE before I got the F350, had...and still do...a '89 F250 460)


Se you around then

 

I registered at Oilburners shortly before buying this old oil burner, but haven't got 'round to registering at The Diesel Stop. I also signed up at Expedition Portal, under the same name, but haven't posted anything yet.

 

Isn't expedition portal the same site that has that awesome e-series 4x4 camper build that people on OB are talking about...that is one sweet rig!!!

Nice to see some big pics of the new beast....more More MORE!!!!!! please

 

Hmmm, dunno about a 4x4 E-series, but the two great rigs that first attracted my attention were the Turtle V and the Earthroamer, both built on F550 chassis.


Both are way too rich for my blood, of course, but the earlier incarnation, the Turtle III, is a little closer to what I can do with what I have.




You bet. I'll take some more pix tomorrow.

 

That's correct, if you have a bolt-action trans it don't need any vacuum. The A/C itself is not vacuum dependent, its the doors inside the piping in the cab that are moved by vacuum-operated servos. Those need just a little bit of vacuum tho, so they will pretty much always work, even with a near-dead vacuum pump. Also, your master cylinder being new only means that the old one failed at some point - likely it developed an internal leak, and/or it started dumping brake fluid inside the booster through its rear seal - both are typical issues associated with an original master cylinder in an aging vehicle.

Dropping the tank ain't hard at all, it sounds way more scary than it actually is - just watch out for the plastic lines on the top of it, they got Ford's quick-connect fittings on them, but with a little more attention to detail it'll be all good.

The midship tank is considered the main tank, the rear is auxiliary and therefore optional - your truck seems to just not have an auxiliary tank, if you can't find a tank selector switch on the dash or a selector valve on the frame rail right to the front of the midship tank then it probably was never equipped with one.


The controller has an afterglow cycle, it lights up the plugs seemingly intermittently, I'm pretty sure that's what you're seeing with your truck. I still wouldn't trust the controller tho, so I'd suggest the manual switch too.


Yeps, that'd be the one.

 

I think this is the one you're thinking of.

1986 Ford 4x4 Camper Build Thread - Expedition Portal Forum

1986 E-350 with a 6.9L IDI engine, C6 transmission and Pathfinder 4x4 conversion.

Niiiiice.

 

Thats it. I'm not to fond of the E-series vans, from the oldies, to the newer ones. But this one makes me drool all over the keyboard.