DIY: Swapping the Fuel Pump on a 1985 Ford F150

Howdy folks, Ed here. Welcome back to Bullnose Garage for the first time, and man, it’s been almost two years. Uh, life, pandemic, all kinds of stuff just got in the way of me working on this truck. And I’ve gotten several comments on many of my videos asking where I am and what’s going on, and people even actually worried about me, and I appreciate that. I really do. Uh, everything’s fine.

But today, the reason that I’m out here right now is because something broke on the Bullnose, and I need to fix it. And the last thing that I want to do is fix something on that truck without bringing you guys along with me. So what broke is this. It’s a mechanical fuel pump. So I try to start my truck every couple of weeks at the very least just to get it running and make sure that it’s okay, make sure the battery stays charged, all that fun stuff. Then about once a month or so, I’ll go out and, uh, actually stretch its legs, run it for, uh, you know, 10, 15 miles, something like that, and then bring it back and make sure that it’s running all right.

And this last time I went out to start it, it was kind of hard to start. I had to give it a whole lot of gas, and it cranked and cranked and cranked and wouldn’t catch. And then eventually it did catch and then die, and then it caught and then died. And then I gave it even more gas, and it caught and then it ran, but it sounded kind of strange, and I started smelling a little bit of gas. And so I turned it off and opened up the, uh, the hood back there and looked underneath, and there’s a big puddle of something, and it wasn’t oil, and it smelled like gas. So I’m guessing it was gas.

And sure enough, I turned the truck on and, uh, went back around to the front, and you could see it was running, but you could see, uh, where the fuel pump was just draining fuel, um, out onto the driveway here. And I don’t know if you’ll be able to see this or not, but these mechanical fuel pumps are designed with a little weep hole right here. So they’ve got a diaphragm inside of here, and then this, this, uh, right here rides on top of a cam inside the engine. And, uh, if that diaphragm goes out, it leaks out of this hole as an indicator to what, you know, that there’s something wrong and you got to replace it. And there’s no fix in the diaphragm. You can’t get in here, and there’s no serviceable parts. This thing is like a one-piece unit, and it’s like 30 bucks, so it’s not worth even trying to fix anyway, even if you could.

Um, so just go out and grab yourself a new one if you’ve got that problem. And these are actually, uh, pretty easy to change. You just get in there, takes a, uh, I think it’s like a 12 millimeter or a half-inch driver with a ratchet, and, uh, you got to get yourself the fuel pump itself. Like I said, it’s about 30 bucks. I got myself a Felpro gasket, like two bucks, and, uh, I didn’t have any of this, so I went out and grabbed some Permatex Orange. Um, that’s what’s good around fuel, uh, just to go around the gasket there. Now, there shouldn’t be any fuel touching that gasket. It’s in between the block and the fuel pump itself. There’s some oil in there, but there shouldn’t be any gas. But anyway, it’s around the fuel line, so in case something were to break or bust, I don’t want that getting out of the gasket material and giving me problems, so that’s why I’m using that.

So let’s get to it. All right, so that right there is the fuel pump. The, uh, line on the bottom of your screen, let me move this up a little bit so you can see, that’s going to the fuel tank, and the one on the top in the back there is going up to the carburetor. And you can see that, uh, there’s a bracket right there, and, uh, that bracket holds the ignition coil connector. Uh, so we’re going to have to remove that bracket as well. Now, not all vehicles have that, but mine happens to. Um, let’s see, and again, this is on a 3006. Uh, your mileage may vary, but, uh, on my ’85 36, this is how everything’s set up.

Now, a lot of these fuel pumps actually have the can facing down. In my case, it faces up. That’s just the way that it is. So I’m not sure if you can see it from this angle here. There’s a couple of bolts that hold that on, so it’s a fairly easy replacement, and we’re going to start by taking off the lines. So we’re going to start with this fuel line from the tank. Um, now, because my truck is outside, I’ve already leaked a bunch of fuel on the ground. I don’t really care that much, but if you’re going to be inside of your garage or in a place where the floor kind of matters, you want to make sure to put something under the truck because you might get some fuel leaking out of here when you take it off. And you just, uh, loosen up this hose clamp here and wiggle it off. Takes a little bit of force, especially if it’s been on there for a while. You just take it right off, and you want to cap this with something. I’m just using a driver extension and then kind of tuck that out of the way.

Now for the other one, we need to get a wrench in there and loosen that up. Now for the line going to the carburetor, I’m going to use a 5/8 flare nut wrench, and I’m going to use that because I don’t want to have to round this nut off and replace this line. So, um, whenever you’re working on, like, brake lines or lines like this, it’s always a good idea to use a flare nut wrench, um, because they have a more positive grip and you’re less likely to round things off. It makes them harder to get on. They’re a little bit, takes a little bit longer to do, but it’s just a little bit of insurance.

All right, that took a while, but we are on. Okay, I’m trying to get you guys a pretty good angle. Um, it’s a little hard to get down in here and see what I’m doing, but the next step is to actually unmount it from the block. And if you can see there, a couple of bolts there, they are half-inch, and so I would use my half-inch ratchet to take them off. Oh, and I was wrong. They’re not bolts, they’re nuts. That’s what happens if you’re not a mechanic. You think you know something, and then you’re not. Because, um, I have this, uh, um, ignition coil bracket behind there, uh, and it’s down by where the gasket is, I’m going to have to take that off so that I can get to the existing gasket and make sure that I get all that gasket material out of there. So this is a 9/16, and it’s right up here, and now I can move this out of the way and actually get to the pump.

So here’s something that I actually didn’t know about and expect. Um, the first bolts that I took, or the first nuts, excuse me, that I took off of the bottom where the fuel pump is at actually held this bracket on. So the actual fuel pump mounting, uh, nuts are still on there. So now I have to remove those, and they are also a half-inch. And up she comes. Now that I’ve got the fuel pump out of there, you can see inside the cam that’s down there that the fuel pump, um, arm rides on. You can also see all the, the gasket material that’s left on there. We want to make sure we get all that gasket material off so we have a nice clean mating surface with the block again for the new pump.

I want to start by using a, uh, a nylon brush just to kind of peel away the gasket material that’s there. You don’t want to be too harsh because you don’t want to, so there’s not actually even a gasket there. It looks like there’s just some gasket material that someone had put on before, and I have an actual gasket that I’m going to use. But, uh, make sure this is nice and clean. You don’t want to be too harsh and rough up too much, but you do have to make sure that it’s nice and clean. And now finally, get this as clean as, uh, I can. Oops, out of the way. I’m going to use this brass bristle brush. Brass bristle brush, um, it’s a little rougher than nylon but not as rough as steel. And this is just, uh, if I had a scratch pad, I’d probably use a scratch pad, but I don’t have one. Um, you could probably use steel wool, but that may be a little bit harsh for me. So that’s just to make sure that I got any remaining gasket material or any other kind of contaminants, uh, definitely off of there. And then I’m going to, uh, take some isopropyl alcohol and dilute it just a little bit. It’s not quite so strong, and give it a good final rub down with a shop rag just to make sure I don’t have anything going around there. Then we will let that dry and take a look at the old pump.

All right, so there’s our old pump, obviously, and our new one. And, uh, you, I mean, you can’t visually look at this and tell that it’s bad. Um, yeah, there’s not really any kind of diagnostics that you can do, um, except run fuel through it and watch it pour out of the weep hole. Um, that’s about it. But, uh, as you can see, they’re not exactly the same, but, uh, they’re definitely going to fit. So now the next job is just to install the new one. Just a quick note here, um, there can be some difficulty with installing these because of the position of the cam. Um, sometimes you’ll have to actually turn the engine. Um, you have to get on the crankshaft pulley with a ratchet or something or a breaker bar and actually turn the engine a little bit to get that cam into the right position to put this in. You can muscle this in without doing that. It’s kind of up to you how you want to do it. This one came out really, really easy, so I’m hoping that my engine is in the correct position to make it pretty easy to install this one. Uh, we’re going to find out.

So my first job here is going to be getting this gasket, um, onto here. The easiest way to do that is to take some of your gasket maker and just run a little bit seal area here, okay? And then you can put your gasket on, and what that’s going to do is that’s actually going to sort of lock the gasket to this part, and that way you’re not fighting with the gasket to stay on, um, while you’re getting it actually on the engine itself. And then while you’re out here, you actually do the same thing the other side, just a real light thin coat here. You don’t want too much. You don’t want it really oozing out, just enough to go around all the surface areas so that, uh, it mates real good and it fills in any micro gaps or anything between this gasket and the block itself. So let’s get to it.

All right, here we go. This is kind of hard with the camera here, but this is a little tight, but you just keep at it, and it’ll get in there. It’s a little hard to work with. I don’t really have a lot of space here for my fingers. There we go. Getting these in is kind of the hardest part, and I can see my gasket starting to get tacky, so I want to make sure that I get this tightened up really quickly. Sorry if you’re wobbling around. Sometimes this stuff is hard to do with the camera in the way. There we go. Now we want to slide our bracket back on. Should be fairly simple, just like that. I’ll get this thing tightened up and be right back with you.

All right, so it’s now installed. The only thing that remains is to put the, uh, the hoses back on. Now this is going to be tricky. You want to make sure that you’re not going to cross-thread that as it goes in. There we go. Now, like I said, wh off my sunglasses. Now, like I said, you want to be careful that you don’t cross-thread this nut right here. Um, it took me a little bit to get it in the right position. You may have to actually bend your line just a little bit to, uh, to get it to line up. You’ll know when you get it right ’cause it’ll start going on, uh, fairly easy. If it’s real, real hard to get on there, then you’re probably cross-threading it, and you don’t want to do that because then you have to replace this nut, flare nut right there, and, uh, that means replacing the whole line. So you want to make sure you’re careful.

And the last thing is putting your fuel line back on, and you just shove it on there, make sure it goes on all the way, and you can, uh, tighten up your hose clamp. All right, now we should be good to go. Now when you go to start this, it’ll probably take a long time because that have to pre, so, uh, be patient, and we’ll see how long it takes.

All right, here we go, and success! There is no fuel leaking out of my new fuel pump. Keep an eye on it just when you first, uh, get it started up. Make sure all your connections are dry, and you put your finger on it, you can actually feel the vibration of that pump lever in there moving up and down on the cam. At this point, I think we’re good to go.

All right, guys, well, there you go. Pretty simple job, a little bit dirty, but what is it? And, uh, pretty cheap too. Actually, it’s about, uh, I think, uh, 30, 40 bucks for all the parts that you need to do it. Um, it’s about an hour’s worth of work for me, and that includes filming. So for, uh, somebody who doesn’t have to worry about dealing with the camera and getting the right angles and going through all that stuff, it’s probably really a 20, 30-minute job at the worst. If you’ve never done it before, um, it’s a little fiddly getting in there sometimes, get those bolts out, and you got to be careful with that fuel line that you don’t, uh, cross-thread that flare nut or round it off or anything like that. But I mean, as long as you’re careful, you’re not going to worry about, uh, the truck runs like a top once again. It’s nice to have the old inline six running great again. Um, sounds as good as it did before, or actually probably better now with the new fuel pump. Uh, took it around the block a couple times, no issues at all, no leaks, no nothing. So it’s very nice to have that thing back on the road again.

As always, if you have any questions, comments, concerns, gripes, internet ramblings, stick them below. Thanks again for watching, guys, and we will see you next time.