Low Coolant but no leak

[lmholmes11]

Alright,

Ever since i've bought my truck (as far back as I can remember) the coolant level has never been up to the proper cold line. Two weeks ago I marked the level with a marker and it hasn't dropped any since then. It is about an 1 1/2 inches below the line. There are no visible leaks under the hood and engine oil smells normal. My low coolant light has never came on. How did it get low in the first place? An engine just doesn't "use" coolant does it?

[DmaxMaverick]

The "cold level" is only a recommendation. Same for the "hot level". If it hasn't moved, then no worries. The coolant is rarely ever filled to exactly the "level" at the factory, dealer, or driveway. The "levels" are close to the max/min, but can't account for your local ambient conditions or exact engine temperature. Coolant and water is very sensitive to temperature, when it comes to absolute volume (the level in the burp tank). If it doesn't move, don't worry. If you don't feel comfortable with where it is, add/remove some coolant and/or distilled water to the level that makes you comfortable. As long as there is a minimum level, enough to prevent cavitation, you aren't hurting anything.

[lmholmes11]

Ok that makes sence. Also another question for you Dmax, do you have a secondary aux. fuel filter? If so, is it pre or post OEM filter and what is your reasoning? I am curious, because I am going to try to install mine again this week. It is time for me to change my OEM filter also, should I change that, prime it up, and then install Aux filter after? Or should i be able to do it all at once. Let me know if you would.

[DmaxMaverick]

Yes on the aux. filter, post OEM. Reason? $1K fuel pump and $4K injector service. My aftermarket filter is more efficient than the OEM, so it made sense to install it after the OEM. The OEM filter is essentially nothing more than a clod sifter. I even use the original single-media OEM filters, if I have them, as the improved elements are more restrictive and shorter lived. My aftermarket aux. filter is a Kennedy Mega.

Priming is priming. You can do them one at a time, or all at once. Doesn't matter, as long as they get primed. It would probably be less messy with an empty system during both. Just be sure to keep the clean side clean, and you should have no problems. To expedite things, and save some wear/tear on your primer pump (and thumb), you can use a vacuum pump at your secondary position filter to fill them. I do not recommend pre-filling them, as the chance of clean side contamination is increased. Clean is the key, especially with the system is opened up. Be sure to flush the lines up to (at least) the last point in the system you exposed. Simply, just pump about a gallon of fuel through the new plumbing before making that last connection (closest to the HP pump). A lot of pumping, but, better safe than sorry. You can also monitor the flow, and watch for air leaks (bubbles as you draw the fuel through). A hand operated vacuum pump at the last connection is very effective for this. Just include a loop of clear tubing before the pump, or catch-can.

[lmholmes11]

Thank you for the detailed response. When using a hand vacuum you connect to the hose closest to the HP Pump i'm assuming. After filling the secondary filter and detaching the hand pump and re attaching to the HP pump, do you have to still prime from the OEM filter to get fuel actually to the motor? Or does it take care of its self when starting?

[DmaxMaverick]

Yes. You want to draw fuel through the entire system, from the tank to the HP pump inlet. Essentially, mocking the HP pump in operation. No big deal, really. If you are installing an aux. filter post-OEM, you will be replacing this connection, anyway. Just save it for last, and be sure to do a thorough flush with the vacuum pump. My catch can is only about a pint, requiring several emptying, but you can fab a larger catch can, if you want. A 1 gallon pickle jar works very well (I made one of these, but it was in other use at the time). Just install a couple barbs in the lid. You can also drill a couple holes slightly smaller than your vacuum pump hoses, and insert them. It only needs a snug fit. The same principal used for brake system bleeding.

Once both (all) your filters and lines are primed, you will still need to pump up the system once all the connections are complete. If you don't, it might start, then die, due to the slug of air at the last connection and pump inlet. Once the pump loses prime, it won't self prime. It shouldn't take more than about 5-10 pumps of the primer on the OEM filter assy.

On another note.......
If you install a fitting/valve/tubing at the bleeder on the filter closest to the HP pump, you can also use your vacuum gage (I use the one on my vacuum pump) to check filter restriction while the engine is idling. JK sells a gage with coupler that fits the OEM fuel system diagnostic port (large brass schrader valve at the front/right of engine), but I haven't got around to purchasing one. Using a gage to check filter health can be very helpful (and economical). It will allow you to replace filters according to their performance, rather than mileage alone. You can even get creative, and install a permanent gage at this location (I'm thinking about it).

[lmholmes11]

Thanks for the help Mav