Reamed my glow plug chambers a few months ago and spent 30 seconds sweating as the car wouldn't start. Finally fired up no issues. Later read something about air in the hardlines and "cracking" them open while cranking being the solution.

I'm about to install fresh injectors (new job for me) and wanted to get a general consensus on whether cracking hardlines is necessary. Reading through the archives, the jury seems to be out. I'm also doing this job without an extra hand so having an eye on the lines while someone else cranks isn't an option (at least today...).

If cracking, is it better to disable the glow plug relay so as not to burn them out during the cranking?
How much of a loosening turn from "tight" is required?
And lastly, must one crack one line at a time or all four at once?

If you crack all four lines at once you will shut off the engine

Have you had the injectors pop tested?

You can crack the lines by yourself. Usually one person smashes the throttle on a cracked line while the other person will loosen and tighten the nut and clean up any diesel that will spurt out everywhere. Ideally you keep the line cracked open until all air bubbles are gone. Since you'll be doing this by yourself you can just warm up the engine and then flog each cracked line.

__________________
1998 Ford Escort ZX2 5 speed - 279,000 miles My Daily

1992 Mercedes 300D 2.5 202,000 - Pure junk
2000 Mercedes E320 Black - 136,000 miles - Needs repair

Don't forget to grease the screw and threads on the spring compressor.

Sure have -injectors came courtesy of Greazzer.
Beginning the install now...

Reaming glow plug should not cause the car to 'unstart' for 30 sec unless you removed the hard lines getting to the GP. Why are you changing the injectors? Any specific reasons? If you are concern about long cranking time after replacing all 4 injectors then replace one at a time, start the car, then next injector. Is it a 240D? Can you prime the lines with the hand pump first?

__________________
Not MBZ nor A/C trained professional but a die-hard DIY and green engineer. Use the info at your own peril. Picked up 2 Infractions because of disagreements. NOW reversed.

W124 Keyless remote, PM for details. http://www.peachparts.com/shopforum/mercedes-used-parts-sale-wanted/334620-fs-w124-chasis-keyless-remote-%2450-shipped.html

1 X 2006 CDI
1 x 87 300SDL
1 x 87 300D
1 x 87 300TDT wagon
1 x 83 300D
1 x 84 190D ( 5 sp ) - All R134 converted + keyless entry.

You didn't say what engine so I don't know if you have a primer pump. How I do it is unplug the glow replay. back off each injector line 1/4 to 1/2 turn from tight, crank for a 10 count (less than 10 seconds). Tighten the lines that are wet. Crank for another 10 count, etc. By the third iteration a 603 should have fuel at each injector. Tighten the last lines, connect the glow relay, start the engine.

Sixto
98 E320s sedan and wagon

I am not familiar with the 240D. The 5-cylinder 300D is self-bleeding. Assuming your fuel system is similar, simply pump up your primer until tight and attempt to start. Pump again and crank. Repeat. Should light off at the third or fourth attempt.

I attach my battery charger in "Start" mode while I do it just to make myself feel better. Just did this today following a diesel purge and filter change.

Yes, removed the hardlines before reaming glow-plug chambers -hence the long crank.
Changing the injectors (had them rebuilt) because they'd never been done before, and it was something I was curious to try...


Anyway, just performed the job and didn't crack. About 3 rounds of cranking for 10 seconds each followed by 20 seconds of rest for the starter motor and she fired right up.

If glow plugs burned out that easily, cars with afterglow relays would be real hard to start.

__________________
When cryptography is outlawed, bayl bhgynjf jvyy unir cevinpl.

While you're cranking w/ injector lines cracked open, make sure you have the throttle held wide open. Shortens the time you have to crank.

__________________
617 swapped Toyota Pickup, 22-24 MPG, 50k miles on swap