A couple of probably dumb questions...

[Mad Maxine]

The 'ol gal has been right as rain since the fuel supply debacle of last summer (knocking on wood...) and so I have been doing more driving and less wrenching, which is a good thing. I am, however, the type of fellow who wonders when the next shoe is going to drop. So, a couple of things I have thought/worried about---

1. Vacuum Pump. I am here to tell you that the old girl is nigh on impossible to stop without the aid of the brake booster. Is there anything I need to look for or preventative maintenance of any kind for the vacuum pump? I could see how losing that thing all at once could be disastrous unless I had about a mile of level ground and a couple of guys to help me stand on the brake pedal.

2. Engine RPM. I'm getting more and more acquainted with diesel engines (or this diesel engine, anyway) but I'm still a whole lot more familiar/comfortable with gassers. My 6.9 is original, and has about 270k miles. I do a little highway driving to and from work, and I don't want to put undue stress on the old girl. At 55, she's turning about 2250 RPM, and everything sounds A-OK. I feel pretty confident that the bottom end of this engine is built to last, but...again, I'm still dumb about diesels. Safe enough to wind 'er up to 2500?

Sorry if these questions are ridiculous. Just something that I've wondered about.

Thanks!

 

[The Warden]

1. Vacuum Pump. I am here to tell you that the old girl is nigh on impossible to stop without the aid of the brake booster. Is there anything I need to look for or preventative maintenance of any kind for the vacuum pump? I could see how losing that thing all at once could be disastrous unless I had about a mile of level ground and a couple of guys to help me stand on the brake pedal.

If there is any preventative maintenance that can be done on the vacuum pump, I am unaware of it. With that having been said, have you taken a look into doing a hydroboost conversion? IMHO it's a very worthwhile upgrade. I would suggest doing some reading on the subject

2. Engine RPM. I'm getting more and more acquainted with diesel engines (or this diesel engine, anyway) but I'm still a whole lot more familiar/comfortable with gassers. My 6.9 is original, and has about 270k miles. I do a little highway driving to and from work, and I don't want to put undue stress on the old girl. At 55, she's turning about 2250 RPM, and everything sounds A-OK. I feel pretty confident that the bottom end of this engine is built to last, but...again, I'm still dumb about diesels. Safe enough to wind 'er up to 2500?

She's fine at 2500 RPM and even above. There are people out there with F-Superduties who are running the engine right at the 3400 RPM governor all day every day and have had no problems. For that matter, my truck used to have a T-19 with no overdrive and 4.10 gears...she would hit the governor at 75 MPH. I cruised at 70 MPH all day long...I think my odometer was around 240 or 245K miles when I swapped transmissions to the ZF5, and I would bet that most of those miles were on the highway at 65+. I would not advise going over the governed RPM without some serious modifications i.e. stiffer valve springs, but I would not have a problem running up to that point.

If a large portion of your driving is on the highway, a ZF swap might be advisable. The T-19 is a stronger transmission, but the ZF5 is plenty strong for the IDI, and that 5th gear will save you quite a bit of headache and fuel. I spent roughly $2,000 in my swap (including transmission acquisition and rebuilding) and have easily saved that much and more in fuel savings. I went from 13 MPG to between 17 and 20 MPG...

Just some thoughts...hope it helps some!

 

[gandalf]

Tim (Warden) is right in all respects of what he has said.

Hydroboost brakes are a great improvement. The first time I realized this was years ago in my '86 F-250. I was driving down one of our expressways with a bed full of dirt looking for a new home, and towing a little bobcat front end loader. Some woman had the audacity to stop for a yellow light. I damned near pulled the steering wheel out by it's roots standing on the brakes. I mean I was straight out, butt up off the seat. I missed her, but not by much.

Engine RPMs. From all I understand, you can drive all day and all night with the engine turning at redline. As Tim says, though, don't take it any higher. Generally speaking the only thing which suffers is your fuel mileage. The 'sweet spot' for RPM is about 2100 to 2200 RPM. Above that your mileage drops a lot quicker than your speed increases.

 

[79jasper]

You can change/add oil to the vacuum pump.

Sent from my SAMSUNG-SM-G890A using Tapatalk

 

[riotwarrior]

Small 10mm bolt on back of vacuum pump allows removal and addition of oil. Most utilize STP oil treatment as preferred lube.

Likely have to remove pump to do the job of oil change/refill

JM7.3CW

 

[Hydro-idi]

You can run off the governor with these engines. I've spun mine to 3900 many a time.

 

[Mad Maxine]

Thanks for the replies, fellas. I appreciate it, as always.
I'll look around on the board and elsewhere for info on hydroboost conversions. 'Til then, I'll check vac pump fluid level as advised.