evo help-no oil pressure on rebuild : V-Twin Forum: Harley Davidson Forums

merc1100sc · 10-27-2007, 07:02 PM

what am i missing. this is the first evo i've messed with.
i had the pump assembly open. are you supposed to prime the pump?

Friday1 · 10-27-2007, 07:24 PM

Quote:

Originally Posted by merc1100sc

what am i missing. this is the first evo i've messed with.
i had the pump assembly open. are you supposed to prime the pump?

Should have oil in pump to MAKE "seal" between the pump body and feed gears. Yes I would. Make sure it is plumbed properly. Closely inspect the "oil diagram'' in the manual (don't ask how I figured that out) as it is easy to connect the wrong hose if you have had all them off. Fill the filter. If still no oil, make a temporary oil feed funnel and connect to the pump where line from reservoir would have gone and start it up, pour oil in the funnel and if it keeps swallowing it, you have something else wrong. May have a gasket with no hole punched in it. Fresh motor job I use 10/30 car oil for initial startup. Run to operating temp and drain and replace filter. Then switch to 20/50. You sure feed gear keys are not broken? You are using known good oil pressure guage? Don't rely on MOCO **** like oil pressure sending unit. Don't run too long if no pressure. Find the cause. Study your oil diagram and see where it should go(the oil after it is pressurized)and find out if in fact it is going there. Hope this helps. Friday

merc1100sc · 10-27-2007, 07:41 PM

friday, thanks for the advice. i'm 100% sure the lines are correct as we only had two of them off but i know those are right. i didnt prime the pump at all. and, i'm assuming no oil pressure because the oil light is on and the top end is loud. typically how does it take for the oil to get up top. didnt fill the filter w/ oil and checked it after startup and still bone dry .the oil pump gears all looked fine. the oil feed from resorvior appears to be the one coming from the bottom of the oil tank into the bottom of the pump assembly(back side of pump). bike is a 98 dyna.

merc1100sc · 10-28-2007, 07:19 AM

does anyone have an oil flow diagram. the manual i have shows the routing of the lines but no flow diagram.

wfolarry · 10-28-2007, 08:34 AM

The filter is on the return side so don't worry about that. Remove the plug for the tappet screen. Pull the spark plugs out & turn the motor over. This should be enough to prime the pump. When oil starts pumping out put the plug back in & you'll be good to go. You can also prime the pump thru this hole with a rubber tipped oil can. I have a fitting that I use to prime the motor but you can do it like this.

wfolarry · 10-28-2007, 08:40 AM

Also if you had the cover off it's very easy to dislodge those keyways. If it doesn't pump any oil with the tappet plug out you should pull the cover back off & check the keys.

merc1100sc · 10-28-2007, 09:49 AM

thanks larry.

when u say the plug for the tappet screen i assume thats the plug located on the crankcase itself and not the top of the oil pump? i briefly tried opening that one up but couldnt get it to turn so gave up.

so, from reading on the net a bit it seems the oil flows from the bottom of the tank to the oil pump(backside of the pump), then gets pumped through the screen you mentioned, then through the motor, then back to the pump then from the bottom of the pump to the oil filter, through the filter, back to the oil tank. is this correct?

wfolarry · 10-28-2007, 09:58 AM

Yes & yes. Get that plug out. If you can't get it out with a big screwdriver & a wrench you can get a 3/8 drive tool for the plug maybe at sears. I got mine from snap-on. If you can't get it out you can go back in the pump, check that it's OK then you can pack it with vaseline to prime it.

merc1100sc · 10-28-2007, 10:23 AM

thanks larry

Geezer-Glide · 10-28-2007, 02:23 PM

Easiest way to do it is a simple way. Do you have an aircompressor? Take the blower nozzle, wrap a rag around it and hold it onto the oil fill spout. Start the motor and give it a blast of air. Had to do this to my 98 Evo after a rebuild.

Friday1 · 10-28-2007, 09:14 PM

It is really easy to dislodge an oil pump shaft key when you push the gear down the shaft. Also the snapring on the end of the shaft can be broken where the pinion gear drives it. NEVER trust a key, snap ring, or retaining device to be properly installed until you inspect it with great scrutiny. I always look at keys and snaprings with a very bright light and magnifying glass. I hate doing a job twice. Hope this helps, Friday

Hillside · 10-29-2007, 05:38 AM

You need to have oil AT the pump, in order to move oil.
If the lines from the bag to the pump are full of air,(air-bound) it will not grab oil, as there is no oil at pump. They are fluid pumps, not air pumps. Pull the oil feed line off, at the pump fitting, until you witness oil coming out of the line, install the oil line, fire it off. If the pump, and all else is in place correctly, it'll grab oil and all will be well.

merc1100sc · 10-29-2007, 06:37 AM

guys. thanks for all the input. i will reinspect it tonight or tomorrow night and report back what i find. i'll try all the steps mentioned above.

**HDWRENCH** · 10-29-2007, 09:30 AM

I just did one here on my own bike and we did all the tricks and it would not prime up.I then put the air hose and a rag over the oil fill hole and put a small amount of pressure to it, primed right up no issues. I have had this happen one other time. They can get air locked and be a pain in the but. Dropping the feed line and all things listed can get you going but in the end if you have it all correct and it will not prime give the air trick a try.

merc1100sc · 11-01-2007, 06:46 AM

GOT IT FIXED.
pulled the 2 plugs in the oil pump and the one on top of the cam chest area, dropped some oil in there, pulled the spark plugs and turned the motor over for a few seconds and it starting pumping fine. Now it purrs like a kitten.
thanks for the advice everyone