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View Full Version : A LOST PRIME...........CAN SHUT YOU DOWN



JIM CHALOUPKA
11-18-2010, 07:07 PM
Follow this recommendation to trouble free travels.

REPLACE YOUR RUBBER FUEL HOSES AT TEN YEARS OF AGE or there about.

How do I know, mine were at thirteen years and failed.

When your coach starts and runs briefly and then stops, don't panic, just get busy. I hope you will be safe where this happens, you will be there for awhile.
To confirm the diagnosis, remove the top of the Racor filter, if you have one and see if it is full of fuel, as it should be. If it is down obtain diesel and fill it. It is doubtful you carry a priming pump, so put the lid back on to keep dirt out and go read a book. After awhile, couple hours you may go back and find the level down again. Look closely in and around the engine compartment and you probably will find no leaks. Dah, ah, ha, go to Home Depot, if one is near by and buy a pump sprayer and 5gal diesel can. You will need them, oh yea get a barbed hose fitting for the sprayer hose and some fittings to attach same to the Racor at the side port. Close the system and begin pumping and looking for leaks. In my case most of 2gal was pumped in before I noticed a slightly wet and weeping hose (it also sucked air) to the inlet of the fuel transfer pump. Get ready to get dirty, your going IN! Find a suitable container to drain any opened lines of diesel (the EPA is watching) as well as many bystanders (they all want to make sure you are doing it correctly) Ha!
Disassemble the offending fuel line and take it to your nearest competent hose supplier. Pray your in an area that has such, not all NAPA, Advanced, Orielyes, Pepboys and such are equipped to make hoses. Be sure to take the old hose for a sample as all hose ends are not created equal.
Reassemble the new hose into the system and fill the Racor and reseal the lid.
Refill the pump sprayer with diesel and connect (after getting another hose for the sprayer, a fill hose for R-12 a/c system) to the R-12 port/fitting on the side of the secondary fuel filter block (this fitting seals with a schraider valve and will not let air into the system when the hose is disconnected)
[my bus has this fitting, yours may not] [you can buy a set male and female at Caterpillar for the outrageous price of $40.00] Pump about 2gal of diesel into the system and disconnect the fill line before the sprayer is empty so as not to introduce air. Start your engine and check for leaks
It is my opinion that one should change the fuel lines as routine maintenance at about a 10 year interval +-

I changed mine inconveniently during a road trip. Changed all I could access from the engine compartment. I turned one two piece line from Racor to the fuel pump into a one piece line.
Each line was about $30.00.

I used Teflon line covered with braided stainless steel and swagged brass ends.
Some Pictures for your enjoyment;

A little difficult to take pics of the conglomeration, but nevertheless, enjoy.

JIM CHALOUPKA
11-18-2010, 07:15 PM
Correction, taking the pictures was easy, in viewing it's difficult for the casual observer to understand.

The new lines will last, well, FOREVER. :cool: :eek:

JIM:o

aggies09
11-21-2010, 02:24 PM
I have been reading this post with casual observation and thinking that my coach is of the same age and condition and that I may need to keep an eye on this. Yesterday I replaced the oil pressure sensor and apparently during my work, I managed to push/pull/tug or otherwise have contact on or around a fuel line, because when all of my work was completed and I checked for any leaks around the sensor, I saw diesel dripping from a fuel line. So now I must embark on the same quest as Jim. Thanks for the tips Jim. I hope that I find myself as capable as you.

As a side note, if you ever find yourself needing to replace the oil pressure sensor, other than getting a little dirty by having to contort your body into the engine bay, it was a piece of cake to change out.

Jon Wehrenberg
11-21-2010, 05:07 PM
On Tony and Jim's buses the ideal priming port is on the base for the secondary filter which is below the power steering reservoir and almost unreachable.

I added a hose to that capped port and extended it out to the side of the coach near the batteries to make priming easier when the need to prime occurs. Some coaches, such as some CC coaches I have seen the port is not only accessible without adding the hose, but it is plainly visible. The time to consider how you will prime your bus if the need arises is to check and see how you will do it before you need to do it. I found out the hard way.

JIM CHALOUPKA
11-22-2010, 10:27 PM
The link will lead lead one to an R-12 fitting if anyone is interested in installing one or just having it in the tool box. The price seems reasonable.

This particular fitting appears to be suited to a flare fitting on the other side. One could attach it to the filter block with a piece of steel covered Teflon tubing to bring the fitting closer to the access door to make it more easily accessible for those that don't like to get dirty.

http://cgi.ebay.com/FREEZE-12-To-R12-Male-Adapter_W0QQitemZ170528132482QQcategoryZ66998QQcmd ZViewItemQ

gmcbuffalo
11-24-2010, 02:52 PM
If one change on fuel line, does one have to force prime it or will just starting the engine take care of the air?

JIM CHALOUPKA
11-24-2010, 05:57 PM
If one change on fuel line, does one have to force prime it or will just starting the engine take care of the air?

I think, if you have the Racor, you may get away without the pressure priming. If you change all the lines at one time it will be best to drain the Racor and all lines involved, so as to not make an environmental mess. I have two fuel shut off valves, be sure to turn off.

After line replacement, fill the Racor (through the removed lid) and crack open the low point fitting of the system to fill as best you are able the newly installed lines (this might take a few moments of waiting) follow through filling the Racor to the top again and close it up. Tighten fitting and open closed valves and fire her up. I believe the running engine will carry over a small amount of air.

You have an 8V-92 so your plumbing might/probably is different.

JIM