Injector leak test

[Rawze]

(04-10-2016 )Coco620 Wrote:  

(04-10-2016 )Rawze Wrote:  I did a leak-down test on mine just before pulling the engine apart. It leaked pretty good on the back 3 injectors when cranking, but even after jumping out of the truck and turning it by hane rioght away as fast as I could,... i could not fine it for the same reason. -- Sometimes it is difficult to find.

-- I decided to simply replace all 3 back injectors together because they had 955,000 miles on them. i will replace the front three at a later date, they are not leaky yet.

The reason I could not find it, is that it would not make enough compression in the leaky cylinder when turning the engine by hand for it to leak good. It is sometimes simply the result of wear in the motor that makes them hard to find. Also, an engine that is completely cooled off, and not at least still somewhat warm will have more trouble maintaining compression when you turn it by hand too.

Thank you Rawze, I am going to try again this morning, if I can't see it would you recommend I fo the same? Replace baclk 3? Truck just turned 500,000 but it had an evil tune since almost new,doing lower end in two weeks.

If it is leaking a lot,.. the yes, it is not a bad investment.

If it is only leaking a tiny bit,.. then it would come down to whatever makes you comfortable.

[Coco620]

(04-10-2016 )dbl overdrive Wrote:  When I can't find it while baring over the engine, I use one of them needles that you use to air up a basketball.
It fits perfectly in the hose and works every time.

Thanks ! Gonna try that in a few

[Coco620]

Hi guys, didn't know if this has happened to any of you, went back out to the truck & it wouldn't do the bubbles even with turning it over, changed the hose & fitting to a smaller size & used the basketball inflation device & nothing...??

[Unilevers]

(04-12-2016 )Coco620 Wrote:  Hi guys, didn't know if this has happened to any of you, went back out to the truck & it wouldn't do the bubbles even with turning it over, changed the hose & fitting to a smaller size & used the basketball inflation device & nothing...??

did the engine temp change? like it was hot the first time then cold or vice versa?

[Coco620]

(04-12-2016 )Unilevers Wrote:  

(04-12-2016 )Coco620 Wrote:  Hi guys, didn't know if this has happened to any of you, went back out to the truck & it wouldn't do the bubbles even with turning it over, changed the hose & fitting to a smaller size & used the basketball inflation device & nothing...??

did the engine temp change? like it was hot the first time then cold or vice versa?

Yes it was the next morning engine didn't run at all

[Peterbilt387]

Hello,i have a PETERBILT 387 with isx 2008,i did the leak test and i found between Aand B bubbles, i replaced injector number 3. Everything fine,i was driving the truck for a pick-up and back to my yard,i left the engine to idle for 3 minutes and start shaking the engine and worst then befor to replace the 3th injector. Did again the leak test and i got bubbles again but now i didn't bar it to find out exactly witch one is leaking.when i did the first time leak test it was leaking only between A and B.thank you in advance

[Peterbilt387]

Hello,i have a PETERBILT 387 with isx 2008,i did the leak test and i found between Aand B bubbles, i replaced injector number 3. Everything fine,i was driving the truck for a pick-up and back to my yard,i left the engine to idle for 3 minutes and start shaking the engine and worst then befor to replace the 3th injector. Did again the leak test and i got bubbles again but now i didn't bar it to find out exactly witch one is leaking.when i did the first time leak test it was leaking only between A and B.thank you in advance

[Coco620]

(04-13-2016 )Peterbilt387 Wrote:  Hello,i have a PETERBILT 387 with isx 2008,i did the leak test and i found between Aand B bubbles, i replaced injector number 3. Everything fine,i was driving the truck for a pick-up and back to my yard,i left the engine to idle for 3 minutes and start shaking the engine and worst then befor to replace the 3th injector. Did again the leak test and i got bubbles again but now i didn't bar it to find out exactly witch one is leaking.when i did the first time leak test it was leaking only between A and B.thank you in advance

Sorry to hear man, one of the experienced gents on here will chime in to help I just looked at the page quick to see the sequence quickly but out of curiosity does the shacking go away when it warms up?

[Peterbilt387]

(04-13-2016 )Coco620 Wrote:  

(04-13-2016 )Peterbilt387 Wrote:  Hello,i have a PETERBILT 387 with isx 2008,i did the leak test and i found between Aand B bubbles, i replaced injector number 3. Everything fine,i was driving the truck for a pick-up and back to my yard,i left the engine to idle for 3 minutes and start shaking the engine and worst then befor to replace the 3th injector. Did again the leak test and i got bubbles again but now i didn't bar it to find out exactly witch one is leaking.when i did the first time leak test it was leaking only between A and B.thank you in advance

Sorry to hear man, one of the experienced gents on here will chime in to help I just looked at the page quick to see the sequence quickly but out of curiosity does the shacking go away when it warms up?

The thing is when is cold doesn't shacking at all, runs very well,when it's warm start shaking