1975 Ford 3550 backhoe cav4 issues

[jrsavoie]

I have a 1975 Ford 3550 backhoe with a cav4 pump.

No start today.

No fuel at the first injector.

No fuel at the injection/ injector line I Took loose at the pump.

I have fuel at the bleeder on the side of the pump.
I read about another bleeder, but haven't found it yet.

I know nothing about these. Even though I've had it over 20 years.

Any links would be appreciated.

What all can I check before giving up and removing the pump?

Will these run if the return line is plugged?
I had that on a couple of 6.5 diesels

 

[Will L.]

Post a bunch of pics or a video. I think I remember the right design on that pump but not sure. Im going back into the 90’s here for this.

I believe the kill switch is a fuel valve controlled by a cable. The return line I think feeds to a foreward injector and then they all daisy chain, then the last one is the return to tank.

First make sure the ip is dry. Any signs of leaking or seeping could be major issue.
Remove the incoming fuel line and be sure it has a lot of flow then reinstall.
Remove the return line and add a separate line into a small bottle where the line is submerged in fuel. Yes plugged lines can always stop ip production.

Need a manual to learn about the bleeder screws. I recall on the metal filter housing and one on the round section of the pump that was just a plug. No others.

 

[jrsavoie]

Post a bunch of pics or a video. I think I remember the right design on that pump but not sure. Im going back into the 90’s here for this.

I believe the kill switch is a fuel valve controlled by a cable. The return line I think feeds to a foreward injector and then they all daisy chain, then the last one is the return to tank.

First make sure the ip is dry. Any signs of leaking or seeping could be major issue.
Remove the incoming fuel line and be sure it has a lot of flow then reinstall.
Remove the return line and add a separate line into a small bottle where the line is submerged in fuel. Yes plugged lines can always stop ip production.

Need a manual to learn about the bleeder screws. I recall on the metal filter housing and one on the round section of the pump that was just a plug. No others.

The IP has 2 lines running to it from the fuel filter.

One to the front and one to the side.


I'd like more info on the line to the front.


I'll get a picture when I get outside.

First we had the Toro sitting behind the backhoe blocking things.

Wife and I Got the valves on that, adjusted yesterday.

While the man that's been helping me swapped the alternator out on my grandson's 2000 Honda CR-V. - I was hoping to make the grandson do the work, but we had to get things done faster.

prime a cav4 pump - Google Search

 

[jrsavoie]

inlet is at back end near outlets. Return is by mounting flange. If hooked up backward, it would not run at all. It's a common are for CAV pumps to leak at throttle and shut-off levers.

I fixed the leaks around the shut off lever a few years ago.
I probably posted a thread then.

CAV Pump, no fuel at injectors

Hi guys, I need some help, I am mid engine swap on my B414 with the BD154 engine. I have the rotary CAV pump. This engine was running when I bought it. So lets start with I messed up and accidently reversed the Feed lines from the filter to the injection pump. I tired to bleed it like that. OOPS....

www.redpowermagazine.com

 

[jrsavoie]

Are there any cav guys around Kankakee, Illinois that want a job?

I haven't found any good tutorials yet.

 

[jrsavoie]

Looking for CAV pump gasket and o'ring recommendations

Working on the 1975 Ford backhoe, They used these pumps on a bunch of different brands of equipment Is there a better gasket and o'rings than OEM? I have to wonder if these Ford o'rings are safe for the new diesel & the gasket seemed kind of cheesy. Ford pt # gasket 384771R1 and Orings -...

www.thetruckstop.us

 

[jrsavoie]

 

[jrsavoie]

Not the current issue

Ford 420 CAV injector pump;;;who to have rebuild it??

Hi guys, long time away from the Ford boards but I am running a Ford again, so here is the latest problem.. I have a 420 industrial loader tractor and the injector pump is leaking on the seals of the shafts that the throttle linkages connect to. The faster the RPMs the more it leaks. I have...

forums.yesterdaystractors.com

 

[jrsavoie]

On the inlet line on the pump, there's another hex, that the feed line screws into.

I couldn't pull the feed line when I unscrewed the fitting.

Might have just been stuck.

What happens when I loosen the fitting that the feed line screws into?

What's under there?

Getting ready to try again. Missed yesterday all together.
Not feeling a whole lot better today.

 

[jrsavoie]

Is it possible / ok, to add a lift pump off a 6.5 diesel ahead of the fuel filter?
To augment the gravity flow from the fuel tank?

I have a 50 micron inline filter I could install ahead of the lift pump.

 

[jrsavoie]

I removed the inlet line to the pump. I have fuel there.

I pulled inlet connector and lifted the spring out. Everything looked clean there.

It says a sticking metering valve will usually stick in the off position. Preventing the engine from starting

I'm wondering if that might be my problem.

 

[jrsavoie]

On the fuel filter there's arrows indicating in and out.

The line on the right has always been in the out port on the right and the plug in port with the arrow pointing in.

I swapped the 2. That's the return line from the injection pump.

It's been the other way forever. From what I read, it will run that way.

After I swapped them I did get more return fuel to the tank. Still just a dribble.

The return from the injectors is clear.

Can anyone verify that the way it's hooked up now is correct?

 

[jrsavoie]

Never figured out anything today.

Tomorrow I need to call and find out which fuel tank screen I need.

I pulled the shut off valve to clean the tank and there was no screen attached.

They used the same tank & screen on a butt load of different machines.
The only one I found said it was for a gasser.

Might be the same.

Wish I could find a parts schematic for this old machine - like Toro has for their machines. Toro's parts page is the best.


Going to add an electric lift pump tomorrow and see if that does anything.

I still suspect the fuel shut off.

I've read they can be problematic. It says to tap on it. Tried that.

Haven't found anything else to try. I hate to take it in to be rebuilt if it doesn't need it.

I'm sure being a 1975, it wouldn't hurt anything.

But now we're into the weekend.

 

[jrsavoie]

1975 Ford 3550 Backhoe

Serial C429973
Unit 5E29B
Model K5011F

 

[jrsavoie]

On the fuel filter there's arrows indicating in and out.

The line on the right has always been in the out port on the right and the plug in port with the arrow pointing in.

I swapped the 2. That's the return line from the injection pump.

It's been the other way forever. From what I read, it will run that way.

After I swapped them I did get more return fuel to the tank. Still just a dribble.

The return from the injectors is clear.

Can anyone verify that the way it's hooked up now is correct?

I switched the line back the way it has been since I got the machine.

From.what I figured out, the only difference is the in arrow runs the fuel back through the filter again - that sounds advisable.
Sounds better than sending it right back to the injection pump unfiltered, even though it just came from there.

 

[jrsavoie]

Never figured out anything today.

Tomorrow I need to call and find out which fuel tank screen I need.

I pulled the shut off valve to clean the tank and there was no screen attached.

They used the same tank & screen on a butt load of different machines.
The only one I found said it was for a gasser.

Might be the same.

Wish I could find a parts schematic for this old machine - like Toro has for their machines. Toro's parts page is the best.


Going to add an electric lift pump tomorrow and see if that does anything.

I still suspect the fuel shut off.

I've read they can be problematic. It says to tap on it. Tried that.

Haven't found anything else to try. I hate to take it in to be rebuilt if it doesn't need it.

I'm sure being a 1975, it wouldn't hurt anything.

But now we're into the weekend.

Found out the mechanical pump on the back of the cav pump is rated at 8 or 9 psi.
The GM lift pump is a good match. We hooked it up and let it run.

I thought we were cranking a little slow, so I added another battery with quality jumper cables. Not sure what size cables - but definitely bigger than #2

Also hooked up the booster charger and flipped it on for cranking. Finally got fuel to the injectors.

The lift pump showed tiny leaks at the fuel filter and the cab pump inlet line.

Finally got it running tonight.
Hope I don't have an air issue when I remove the electric lift pump.

I intend on installing the lift pump permanently with a relay, if it ever gets to the top of my list. At least we can get the mower out now that the backhoe will start.

I could use a flock of sheep right now.

Gotta get the 94 put back together, so I can get it out of the way to work on mowers and get mowing.

Rain tomorrow. Not sure when we'll actually be able to start mowing now.

 

[jrsavoie]

Now we have a fuel leak
We haven't figured out where the leak is coming from.

We're guessing the fuel tank.

I'd like to put a little pressure to the fuel tank.

Would 15 lbs. Be good?

Too much? Not enough?

Any ideas on sealing up the fill cap?

The return line runs into the fuel fill neck under the cap.

Chànging the fuel tank out is a time consuming ordeal. Lots of stuff has to come apart.

I want to make very sure it's the tank leaking before I tear into it.

Fuel Tank Fits Ford 515 4400 3500 4200 535 4000 420 3550 4500 4600 | eBay

3500, 4000, 4200, 4400, 4500, 4600 (1975-11/83 diesels). NOTE: 13 gallon tank. This tank will not fit the 4000su. Fits Ford Tractor Models Fits Ford Construction & Industrial Models For Tractors with One Arm Steering Sectors.

www.ebay.com

 

[ak diesel driver]

More like 2-5

 

[jrsavoie]

More like 2-5

Thank you very much. Big difference there.

 

[jrsavoie]

More like 2-5

Any ideas on the best way to seal up that style fill cap to pressurize the tank?

I can hook the mighty vac to the return line in the neck.

I also have a snap on radiator pressure tester.

I had a rubber plug, with the built in fitting, that you tighten down to deal a hole. Probably not the right size, if I can find it.

Do they still make those?

Are they readily available?

Thanks