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Can a HPOP leak cause extremely low LPO pressure?

9257 Views 15 Replies 4 Participants Last post by  Texascadillac42
04 F350, 114k miles. Truck has a hard start/no start condition. Mechanical oil pressure gauge is installed in the low pressure system, and when the truck finally starts it builds about 25psi at cold idle. Which quickly drops to 15psi as the truck warms up, and will soon be at 0-5 psi when the truck warms up more. Can a leak in the HPO system be large enough to create a low oil pressure condition in the LPO system? Or should I be looking in the LPO system first? Thanks.
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yeah, ive seen it happen,

basically you need to verify that you have good oil in the sump, if you now know the oil is good, check oil pressure while cranking, if low try overfilling the crankcase by only a few quarts and re check, if this fixes it you have a cracked or damaged pick up tube, if still no change, remove the oil filter and have a buddy hold down the little button on the top of that black thing, and have someone crank the engine and watch that the filter housing fills up with oil,if it doesnt you need a new oil pump if it does fill up you can count on a hpop leak so big that the lpop cant supply the hpop with enough oil.

that should send you down the right path.
are you are basing your readings off of the gage? if so, try to avoid driving the truck till you can get a scanner hooked up and see whats going on
well im glad you solve the issue, i have only seen this problem arise twice, once was a bad hpo stainless line, it gushed pretty bad, and the other well, it leaked at where yours is, if you remove the hpop you will see little casting holes and international or who ever manufactured the pumps pressed small little bb's in there, stupid huh? anyways on one of my trucks the bb came shooting out, and was soon found once the the hpop was removed, sitting their in the galley of the motor.
nah, something like that would get stuck long before if floated to anything critical, is kind of a decent size, so you very well may find it a few oil changes down the road lol.

im glad you solved your issue, now have fun putting it all back together.
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