1989 S1600 x Uhaul truck 7.3 IDI

[Big Bart]

A normal truck. Ahhh....that sounds so good! Sounds like time to leave it alone. Runs and sounds really good to me.

One more thing I'd like to know and it may only apply to Uhauls. It has electric over oil over brake fluid or whatever. It's electric but has an oil pressure light. Brakes are outstanding. Changed brake pads all around and changed the brake fluid when I first got it. Before that the oil pressure light would sometime come on. Call the Uhaul mechanic that I got it from and he said it was just dirty senors not to worry. Turn off the switch and restart and it likey wouldn't show up again for a long while. But now it stays on most of the time, like all the time.

So I'm wondering if the best approach is to remove the sensor, clean, put in a new one, or just go to a manual actual pressure gauge.

Likely your pressure sensor is bad. Maybe start by replacing it. The IH engine is more about volume than pressure. IDI’s run about 12-15 psi at idle and 45-65 psi on the hwy.

But a mechanical gauge would also be a good idea, just takes a little time to put in.

 

[hrsitton]

If you go into higher elevations, all bets are off for it continuing to run nicely since it's all hand set.

I'm at a little over 5k elevation at the present. I've had it up to 9k and yep, that required at least one more gear down.

 

[IDIBRONCO]

Likely your pressure sensor is bad. Maybe start by replacing it. The IH engine is more about volume than pressure. IDI’s run about 12-15 psi at idle and 45-65 psi on the hwy.

But a mechanical gauge would also be a good idea, just takes a little time to put in.

Except he's talking about his brakes here.

 

[Booyah45828]

It likely is a standard hydroboost system, but with a back up electric pump in case your power steering pump fails. Pretty common on a lot of your juice brake MD stuff. There is a pressure switch that turns on the light when there is no hydraulic pressure, it also should come on and stay on if the electric motor fails. Before starting, your supposed to press the brakes with the key on to check the electric pump operation.

 

[Big Bart]

Except he's talking about his brakes here.

My bad. I thought we we still on the engine issues.

 

[hrsitton]

Before starting, your supposed to press the brakes with the key on to check the electric pump operation.

Didn't know that. But when I bump it accidentally when working on stuff even with the key off something does come on that sounds like a motor.

 

[hrsitton]

The IH engine is more about volume than pressure. IDI’s run about 12-15 psi at idle and 45-65 psi on the hwy.

I had thought (from somewhere?) that the mechanical International pump put out 4 PSI. There's that memory thing again.

Edit: Found this.... https://www.oilburners.net/threads/7-3-idi-fuel-pressure.41363/

 

[Booyah45828]

Didn't know that. But when I bump it accidentally when working on stuff even with the key off something does come on that sounds like a motor.

It might run with the key off too. I'm not sure, I haven't worked on one in a while. There should have been a sticker or something above the visor detailing the start procedure.

 

[hrsitton]

It might run with the key off too. I'm not sure, I haven't worked on one in a while. There should have been a sticker or something above the visor detailing the start procedure.

Just checked. Sticker gone. I've had it 11 years and the 10 years before that it was a UHaul service truck that carried batteries, tires, and you name it. So stickers didn't have to be maintained for the public I'd think. But now I'll be checking when I get in just to be sure. (before all the other bells start ringing) Bu the light does go out when it's started, but then goes on down the road a ways. But brakes keep working fine.

 

[IDIBRONCO]

I had thought (from somewhere?) that the mechanical International pump put out 4 PSI. There's that memory thing again.

Edit: Found this.... https://www.oilburners.net/threads/7-3-idi-fuel-pressure.41363/

That's fuel pressure. Bart was talking about engine oil pressure while you were talking about the pressure in the electric over hydraulic brake boost system.

 

[hrsitton]

Bart was talking about engine oil pressure while you were talking about the pressure in the electric over hydraulic brake boost system

Sorry Bart. That's about the oil pressure I run. I shouldn't have even brought the brakes into the mix. I was already told way back where I bought the truck it was probably just a dirty senor. So down the line I'll just buy an electronic gauge and sensor and mount it on top of the dash.

Truck is happy, I'm happy!

 

[Big Bart]

Sorry Bart. That's about the oil pressure I run. I shouldn't have even brought the brakes into the mix. I was already told way back where I bought the truck it was probably just a dirty senor. So down the line I'll just buy an electronic gauge and sensor and mount it on top of the dash.

Truck is happy, I'm happy!

Now worries, the thread went another direction and got confusing. Generally a new thread is used for a new issue.

Some folks do write a thread about their journey of getting a dead truck up and running, rebuilding a engine, or refurbishing their truck. But that tends to be more of a FYI VS help wanted.