How to install a primer pump

dougyes · April 16, 2012, 02:29:31 PM

I've replaced a bunch of fuel lines and I still get air in the line, especially after the coach sits for a few days. After priming the filter it fires right up. I was thinking of installing a little fuel pump at the tank to add some boost to get it started. Can I put one inline in the fuel line? Advance Auto sells a bunch of inexpensive little fuel pumps. Any suggestions on which pump to get?

belfert · April 16, 2012, 02:34:06 PM

I would figure out why the coach is losing prime after sitting just a few days and then worry about a pump once it is fixed. A pump would just be a band aid and not a real fix. My bus can sit all winter and it will fire right up after all that time.

robertglines1 · April 16, 2012, 02:37:04 PM

Checked your profile: what kind of bus do you have? Bob

dougyes · April 16, 2012, 02:39:10 PM

102 DL3 with a series 60

TomC · April 16, 2012, 03:09:49 PM

I agree with the bandaide-my '77 AMGeneral transit bus can sit for weeks and still fires up like I ran it yesterday.
I watched Don Fairchild prime up my 8V-71 after he replaced the head to head cross fuel line. He first disconnected one hose at a time-filled the hose with Diesel then reattached it. Then filled the fuel filters with fuel and tried to fire the engine. He did the whole thing 4 times, then it started and kept on running. While Don has used a primer pump on the secondary filter-which is AFTER the fuel pump-he will not use any kind of primer pump before the fuel pump. Why-he says that the seals on the low pressure transfer pump can easily be blown out by a primer pump. If you do put a primer pump in, only after the fuel pump-not at the tank. Good Luck, TomC

papatony · April 16, 2012, 04:09:29 PM

Doug some where on the line from the tank to the first filter there is a back flow valve that keeps the fuel from draining back into the tank. start looking back toward the tank it should be close to filterer. Tony

Dreamscape · April 16, 2012, 04:27:24 PM

I just finished an engine swap. One post I read in the archives suggested what Tom C said. I just finished bought my pump at Oreilys. Installed before the Secondary filter and it worked fine. My system was pretty dry. Clifford also suggested the same location.

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bevans6 · April 17, 2012, 05:21:27 AM

Here is the type of pump I used. I used the 24 volt one. I just put it in line in the main fuel line to the primary filter, on my 8V71 I don't think there is anything that will be hurt by 10 - 14 psi for 10 seconds... I just run it for a few seconds, you can hear when it reaches pressure and that means everything is full. If I leave it on, the fuel pressure switch stops the engine from turning over. I suspect that your main line check valve needs servicing.

Brian

Oonrahnjay · April 17, 2012, 06:22:49 AM

Quote from: bevans6 on April 17, 2012, 05:21:27 AM(snip) I used the 24 volt one. I just put it in line in the main fuel line to the primary filter, on my 8V71 (snip)

Yeah, but a Series 60 is an electronic engine and they're often touchy about fuel pressure (the fuel pressure is read by a sensor and it's factored in by the computer for Start of Injection timing, Injection Quantity, etc.) For an ordinary mechanical engine, I think a primer pump is a good idea; for an electronic engine, I'd definitely find the problem and fix it.

buswarrior · April 17, 2012, 07:16:40 AM

The new stuff all comes with a priming pump from the factory.

What are they doing?

happy coaching!
buswarrior

luvrbus · April 17, 2012, 08:34:25 AM

Priming pumps don't hurt the seals Don must have had a bad pump seal to start with, on the older stuff 2 strokes that is a 65 psi + pump I have one in the shop I saved for Don took me 131 lbs of air pressure to blow the seal and it was a wore out pump

good luck

Van · April 17, 2012, 10:38:59 AM

I can tell you what the fuel pump does not like, and that is to be starved for fuel. I have one with a sheared drive gear shaft (sheared within the pump housing) that I pulled from my old 6-92 in Amarillo bringing the coach home. I was having the same issue LarryH was having (in the other thread) in B-town Ca. cept that I had a collapsed supply line to the primary, which starved it of fuel and lubrication to the drive gear shaft. While stuck in Amarillo waiting for a replacement to come in, I pulled the old one apart and to my amazement, the shaft was separated from the gear and pulled out of the housing. Here's some pix.

V

Van · April 17, 2012, 11:30:12 AM

My Primer is installed inline, before the primary filter. Almost 5 years, and no problemo's

Iceni John · April 17, 2012, 11:35:05 AM

Quote from: luvrbus on April 17, 2012, 08:34:25 AM
Priming pumps don't hurt the seals Don must have had a bad pump seal to start with, on the older stuff 2 strokes that is a 65 psi + pump I have one in the shop I saved for Don took me 131 lbs of air pressure to blow the seal and it was a wore out pump

good luck

Whew! Good to hear that. I installed a Facet-Purolator Posi-Flo 60100 electronic fuel pump for priming, and it's between the primary filter (in my case, a Racor 900FG) and the engine's fuel pump. I specifically chose this pump because it's for older carburetor-equipped cars which need lower fuel pressure than newer fuel-injected cars. I think it produces only a few PSI, which I hope won't be damaging any seals! I've had to use it only once, and after running it a few minutes the engine started right up with hardly a hiccup. So far, so good.

Thanks, John

dougyes · April 17, 2012, 01:09:39 PM

Van, What model primer pump is that in the picture?
Guys, I'll try to find the check vale.