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Bus Discussion => Bus Topics ( click here for quick start! ) => Topic started by: BlueScarecrow on March 12, 2016, 06:40:21 PM

Title: 8V71 Fuel Pump Woes
Post by: BlueScarecrow on March 12, 2016, 06:40:21 PM
I've been trying to prime my new fuel pump by introducing an air nozzle into the fuel tank and using a rag to cover the filler hole. I've loosened the bottom line at the fuel pump and can see fuel coming out, but I just can't seem to get the engine started. Next, I'm going to replace the Inverted 90 degree flare fitting at the fuel pump with a "Tee". One end will attach to the fuel pump, the middle end will have an Inverted Flare Fitting to accept the fuel ling coming from the primary strainer and the end facing the rear of the bus will have a valve with a hose fitting. My goal is to build a "Mason Jar" with two hose fittings on top. One hose will go to the valve at the "Tee" and the other fitting will accept a hose going to my A/C Vacuum pump. The plan is to suck fuel from the tank all the way through the primary strainer and up to the "Tee" and into the "Mason Jar". Once I see all the air bubbles are gone, I'll consider it primed. This seems like a for sure method and only requires one person and since it is before the fuel pump, there is no chance of destroying any seals.

This is assuming that the old pump was bad. The "Fork" off of the old pump looked good, but I have no way of knowing if the blower is turning the pump. Anybody ever have any problems with the fork or the blower turning the fuel pump?

Thanks!


Mike
Title: Re: 8V71 Fuel Pump Woes
Post by: luvrbus on March 12, 2016, 07:02:49 PM
I wish I was in Scottsdale this weekend I would help you I see from the zip code you are in the Goldwater and Osborn area that is far from where we go . What you are trying to do is not going to work you need to prime the engine the fuel pump will take care of it's self, buy your self a cheap electric fuel pump with a couple feet of hose and a few fitting from Auto Zone. Remove the plug from the top of the primary or secondary filter base install the fitting and pump a couple of gals of fuel through the system and it will fire and you are not going to hurt the pump that is a 70 psi pump and the extra fuel is return to the tank it's a easy process   

good luck  
Title: Re: 8V71 Fuel Pump Woes
Post by: Beesme on March 13, 2016, 06:46:34 AM
I lost prime right after I bought mine . I bought inline fuel pump for diesel from Napa . Works great and showed me where bad fuel line was! It has been permanently mounted inline for a few years now !
Title: Re: 8V71 Fuel Pump Woes
Post by: jackhanow on March 13, 2016, 07:43:46 AM
I used a shop vac. I used vinyl hose from the feed line at the pump to a 5 gallon plastic jug from the car detail shop. Turned on the vac and stuck the hose in the bung and waited about 30 second til I saw the jug was starting to fill. I'm in Tucson and I may be able to come up to Scottsdale next weekend. You can also use a vac source for your car as well. I do it all the time on pickups that don't have a lift pump when I change the fuel filters. On my mc5 I thought it was the pump but I found a leak at a fitting and the primary filter had a ding on the edge of the can. Let me know and I'll come up.
Title: Re: 8V71 Fuel Pump Woes
Post by: BlueScarecrow on March 13, 2016, 10:07:44 AM
Thank you all for writing.

Sorry... can't afford a mechanic right now. I'm retired and funds are low at the moment. I am very mechanical and a quick study.

I am interested in the electric fuel pump... Beesme, can you tell me what the model number is on your electric fuel pump?

I'm looking to install something that will get me out of trouble quickly if I run out of fuel at 3 am and it's minus 15 below zero.

Thanks!


Mike
Title: Re: 8V71 Fuel Pump Woes
Post by: Iceni John on March 13, 2016, 10:29:18 AM
Quote from: BlueScarecrow on March 13, 2016, 10:07:44 AM
Thank you all for writing.

Sorry... can't afford a mechanic right now. I'm retired and funds are low at the moment. I am very mechanical and a quick study.

I am interested in the electric fuel pump... Beesme, can you tell me what the model number is on your electric fuel pump?

I'm looking to install something that will get me out of trouble quickly if I run out of fuel at 3 am and it's minus 15 below zero.

Thanks!


Mike
I use a Facet-Purolator "electronic" fuel pump plumbed in parallel with the main fuel line between the  Racor primary filter and the fuel pump.   I put a switch and idiot light for it on my rear start panel, so now to prime the engine I just flip a switch and turn one valve  -  easy!

John
Title: Re: 8V71 Fuel Pump Woes
Post by: chessie4905 on March 13, 2016, 11:04:41 AM
Here:  http://www.ebay.com/itm/NEW-AIRTEX-E8131-FUEL-PUMP-FOR-24-VOLT-LARGE-DIESEL-APPLICATIONS-/222049311309?hash=item33b32b9a4d:m:mtMCHJRq9rpVRjigwGSVQVw&vxp=mtr (http://www.ebay.com/itm/NEW-AIRTEX-E8131-FUEL-PUMP-FOR-24-VOLT-LARGE-DIESEL-APPLICATIONS-/222049311309?hash=item33b32b9a4d:m:mtMCHJRq9rpVRjigwGSVQVw&vxp=mtr)

Install it permantly with good quality fuel hose. I prefer SS braided. You' ll also make life easier in the future when changing filters or running out.


Also helps from burning up starter or wearing down batteries. You could run it with a momentary switch, as it doesn't need to run except when needed.
Title: Re: 8V71 Fuel Pump Woes
Post by: Lin on March 13, 2016, 02:52:26 PM
In the meantime before you get an electric pump installed, you can fill a garden spray can with diesel and pump it into the fitting on the secondary filter.  It may not be as simple as a switch but will work and get you on the road.
Title: Re: 8V71 Fuel Pump Woes
Post by: Beesme on March 13, 2016, 03:59:11 PM
I will look and see if there is number . But I just went to Napa and they had one foe diesel with and one for gas I'm sure u would get right one it was like 30$ give or take
Title: Re: 8V71 Fuel Pump Woes
Post by: luvrbus on March 13, 2016, 04:12:32 PM
These are the ones I been using because they 3/8in Airtex 8153  for 12V Airtex 8135 for 24V
Title: Re: 8V71 Fuel Pump Woes
Post by: jackhanow on March 13, 2016, 08:53:24 PM
I was just offering my help, not looking for money. I have other work around there and like to learn tricks from others. Comes in handy.
Title: Re: 8V71 Fuel Pump Woes
Post by: BlueScarecrow on March 14, 2016, 09:59:36 AM
Thank you all for your wonderful suggestions.

Has anyone ever had any problems with a new fuel pump not turning because of blower problems or a bent fork?

Thanks!
Title: Re: 8V71 Fuel Pump Woes
Post by: luvrbus on March 14, 2016, 10:35:37 AM
The forks will round out from time to time but I never saw one bend,if the blower drive snapped the blower will not turn the fuel pump drive is the blower turning ?. That is easy to check without much work just remove the bearing cover for the governor shaft it has a 7/8 hex head about 6 inches from the fuel pump, nothing is going to jump out and bite if the weight shaft and bearing is turning the blower is turning   
Title: Re: 8V71 Fuel Pump Woes
Post by: moosemanusa on March 14, 2016, 01:11:37 PM
I've done the whole air line into the fuel tank with a big ole rag, then removed the return on the head (was a DD 50 motor) to push the air out of the filters and head.  Started straight up afterwards..

Never thought about using a shop vac to suck the diesel through.. frigging genius!