[RammerJam]

Just talked to my buddy about changing the fuel filters. He said he primes them with ATF because cycling the key doesn't always get all the air out. He must have been talking about the frame-mounted filter because he said he leaves it a little loose to get the air out.

Is there anything wrong with that? Has anybody had any problems doing that?

I hate to 2nd guess him. He works on vehicles for a living. I don't. But things change and I'm not sure how many new CTD's he sees.

 

[tsconver]

Would not run ATF full strength through a modern CTD. A few key cycles and it will self prime just fine.

 

[RammerJam]

Would not run ATF full strength through a modern CTD. A few key cycles and it will self prime just fine.

I'm willing to take your word for it but is there some reason for not doing it?

I've read it before but I gotta wonder if anybody has had a problem doing it. Never heard why it shouldn't be done. I've read, muttered, something about Common Rail something or other but I don't know.

Thanks for your input.

And, oh. About how many key cycles and should I 'bump' the starter?

 

[Grit dog]

Yes, because it's stupid. Why would you run 2 qts of straight ATF through the engine and if you need to fill the filters to prime it (you DON'T) why would ATF prime better than.......wait for it.....DIESEL?

Yes ATF, diluted, is a great injector cleaning solution, in general, like 1 qt per tank full.

Your buddy should not be listened to for advice if that's the advice he's giving. Change your filters, prime it up, start truck, drive it.

 

[Ltngdrvr]

Just talked to my buddy about changing the fuel filters. He said he primes them with ATF because cycling the key doesn't always get all the air out. He must have been talking about the frame-mounted filter because he said he leaves it a little loose to get the air out.

Is there anything wrong with that? Has anybody had any problems doing that?

I hate to 2nd guess him. He works on vehicles for a living. I don't. But things change and I'm not sure how many new CTD's he sees.

Your buddy must be old school, and be talking about older diesels, not common rail electronic current models.

On older mechanical diesels, priming the fuel filters with ATF is an old trick, that provides extra lubrication to the pump and injectors and the ATF will burn just like diesel fuel in those old engines with just a little smoke when first cranked after the fuel filter change. I always did this way back when, but not on these new trucks.

Late model common rail diesels should not be treated this way, can cause damage to the pump and pintle on the injectors.

 

[Mike Wood]

I just replaced both fuel filters (engine mounted and rear mounted) last weekend. I drained them completely, removed, installed new filters, and just cycled the key a few times as suggested. Upon the first "bump of the key" (I have a push bottom in the Laramie) it stumbled and stopped trying to crank. Cycled key once more then she fired right up.

Nothing to it

 

[Burton12387]

And, oh. About how many key cycles and should I 'bump' the starter?

I also have push button start. I cycle to the run position (listen to the fuel pump run and turn off), i cycle around 10 times, and it starts normally after. You could probably get away with fewer cycles. But mine has always started normally without stumbling using 10.

 

[SoCalAdam]

Just talked to my buddy about changing the fuel filters. He said he primes them with ATF because cycling the key doesn't always get all the air out. He must have been talking about the frame-mounted filter because he said he leaves it a little loose to get the air out.

Is there anything wrong with that? Has anybody had any problems doing that?

I hate to 2nd guess him. He works on vehicles for a living. I don't. But things change and I'm not sure how many new CTD's he sees.

The new CTD's will purge any air in the system back to the tank.

What your buddy is talking about is way old school, like 4BT/6BT mechanical diesel fuel pump old.

It is not relevant to modern computer controlled engines.

It IS relevant to 1950's diesel tractors.

 

[slowride14]

I agree with Burton12387, I just did my filters a week ago, I cycle the push button to run more times than the manual states, give it a few extra seconds after I hear the fuel pump turn off just for fun. Usually takes a few seconds of turning over to fire but never had an issue with the pump priming the system itself.

 

[hillbilli]

Yeah thats not somethig that i would do on these new diesels. Yes its an old school trick, but i could see the exhaust fumes fouling the exhaust treatment system in some way if done on a continued basis, there is more going on that just filtering the soot, there is also a several chemical reactions going on and the introduction of a foreign chemical such as ATF may throw those reactions off

 

[Spazoid]

I wouldn’t.
As stated your buddy is using an old school method. But I wouldn’t do it in any common rail because of injection pressure. It’s alright for an older diesel with say a PLN system because your injection pressure is only in the 8000psi or lower full throttle. On a common rail your talking injection pressures of 35,000psi+ Full throttle. I’m no chemist or scientist but I’d imagine if ATF had the same Atomization and Lubricity properties as diesel the manufacturers would probably recommend it or at least mention you could use it.
Just my .02

 

[RammerJam]

I can't bump the starter on mine. It's a key-start. When I engage the starter, it cranks until it fires up.

I guess I'll just have to cycle the ignition on and off several times.

You good folks are saying I don't have to bleed anything after the new filters are installed? Just cycle the ignition switch?

Thanks to all for your remarks. I'm sure many others in here benefit from them as well

 

[hillbilli]

I can't bump the starter on mine. It's a key-start. When I engage the starter, it cranks until it fires up.

I guess I'll just have to cycle the ignition on and off several times.

You good folks are saying I don't have to bleed anything after the new filters are installed? Just cycle the ignition switch?

Thanks to all for your remarks. I'm sure many others in here benefit from them as well

Correct, just cycle the ignition several time and you can hear the lift pump turn on and run for a few seconds when going to ACC position with the ignition (keep foot of the brake so it wont start)

 

[Ltngdrvr]

Correct, just cycle the ignition several time and you can hear the lift pump turn on and run for a few seconds when going to ACC position with the ignition (keep foot of the brake so it wont start)

Not the ACC accessory position, the switch has to be turned to "ON" for the lift pump to run.

And, I never can hear the pump run on mine.

 

[Ltngdrvr]

I can't bump the starter on mine. It's a key-start. When I engage the starter, it cranks until it fires up.

I guess I'll just have to cycle the ignition on and off several times.

You good folks are saying I don't have to bleed anything after the new filters are installed? Just cycle the ignition switch?

Thanks to all for your remarks. I'm sure many others in here benefit from them as well

No bumping the starter needed.

My procedure for priming the fuel filters is to turn the key to "ON", wait 15 seconds, turn key to "OFF" for 5 seconds, then repeat this cycle a total of 6 times, this takes 2 minutes, then start the truck as normal, and let it run for 10-15 minutes to clear any possible remaining air. Works every time.

 

[AirGrabber]

I cant help but wonder if the person recommending the use of a filter canister full of straight atf to help prime fuel on a common rail is probably also missing a few fingers or sliced finger tips from trying to bleed the individual injectors by cracking the line nuts first...

With all honesty tho, many older +40 people who are buying newer diesels have been around diesels for many years, and have not had, owned or maintained anything newer yet to know any different. Not much kept the older diesels from running and many of the old tricks to getting them back up and running were still relevant on pick ups, big trucks, heavy equipment, farm machinery ect.. into the mid 2000s.

 

[ofelas.5z]

What are these strange fuel pumps that start priming when the key is in the RUN/ACC position?

Dark magic & voodoo, indeed.

 

[AirGrabber]

What are these strange fuel pumps that start priming when the key is in the RUN/ACC position?

Dark magic & voodoo, indeed.

Bump your starter once without starting and youll hear your magical ghost intank pump prime your fuel system for 10 sec.
The same thing that runs and makes that pump come alive makes santa clause and the reindeer fly.

 

[RammerJam]

What are these strange fuel pumps that start priming when the key is in the RUN/ACC position?

Electric? :confused013:

 

[ofelas.5z]

I just tried this strange & wondrous "key on" fuel pump priming procedure.

All I can hear is the cassette tape motor whirring

Bump your starter once without starting and youll hear your magical ghost intank pump prime your fuel system for 10 sec.
The same thing that runs and makes that pump come alive makes santa clause and the reindeer fly.

Electric? :confused013: