ROOF

Thank you for visiting the Routemaster Owner and Operator's Forum (ROOF). Please feel free to use this forum for the mature discussion of any issues of interest and relevance to Routemaster owners. Please do not use this board to publicise your feelings about individuals, National or Local Government or TFL policy. Owners of other London bus types in service during the 1950s, 60s and 70s are also welcome to contribute to this forum.

Please note, the ROOF website no longer exists. The link from the Forum does not work anymore.  Useful information and links from the website has been posted to the Forum.

Please do not respond to abusive posts but notify ROOFmoderator 1@outlook.com.


ROOF
Start a New Topic 
Author
Comment
Fuel feed issue

Can anyone tell me how the feed pipe is properly secured to the top of the fuel tank? When my bus was delivered to me, it had an issue with fuel line and as a quick fix, the mechanic ran a line from the fuel tank, through the lower saloon and into the engine compartment. I have since had that line moved under the bus. But, what was a "quick fix," has turned into a major problem. You see, the feed pipe had been secured by epoxy at the top of the tank. The Arizona heat has rendered the epoxy ineffective. So, the feed pipe keeps moving. When the bus stopped running completely, it was determined that the pipe sank to the bottom of the tank and sucked in sediment, which clogged the line itself. We blew out the line and re-epoxyed the pipe. The bus stopped running again and when I checked the feed pipe connection at the top of the tank (under the trap), it was once again freely moving around. So, I need a permanent solution. Any help would greatly be appreciated.

My bus number (if any): RM187

Re: Fuel feed issue

There should be an elbow connection brazed or soldered to the top of the tank. You'll probably find the diesel affects the epoxy a well. I don't have a spare tank to have a look at, but no doubt someone else will be along soon with more advice.

My bus number (if any): RML2532

Re: Fuel feed issue

I've seen this before and not just on buses. Particularly in dry heat conditions.

Although the feed and dribble return pipes are accessible through the trap door in the saloon floor, fixing the mounting of them can be rather hard to do in situ.

I think the best option may be to drain and remove the fuel tank completely ( which gives a change to clean and repaint the area obscured by it) An empty tank can be removed in very little time and very easily.

Have the tank flushed out and cleaned. The nice thing is it will dry out well in the dry heat of Arizona. Can take an age in Northern Europe!.

Do ensure the fuel filter is replaced and replaced regularly. This will save on wear and damage to the pump and injectors. Be careful with the filter fittings, avoid overtightening.

Check the integrity of the tank, there are a few places where corrosion can get a grip. Often the areas concealed.
This can be very small pinholes but enough sometimes to affect the venting.

One option is to reline the tank using a petrol and diesel resistant 'slosh sealant' There is probably a version for high temps as it is a US invented product. This forms a flexible glass like coating on the inside tank that really lasts.
It won't be cheap and will require a few spare pairs of arms!

If the tank is OK, just give it a clean inside and out. A coat of protective paint and likewise to the mounting fittings.

Remove the entire fuel line if you can.
Again a tiny fracture may be taking in air but not obviously weeping diesel. This is because the viscosity of the diesel remains stable in heat or a leak might not be in an accessible place.

Pressure test the pipes and check all the joints - unions and threads.

It is possible while this is all out to fit a sender unit for a fuel gauge. Some of the latest HGV units are very simple devices and can be fitted with minor work to the tank - as long as the tank is vapour safe.

This is the point where the fuel line can be repaired and installed correctly. I can't offhand remember fully the fitting and what was brazed and what was bolted with a gasket. But it will be obvious once accessed.

Re: Fuel feed issue

Yes the tank can be removed or replaced quickly and easily if you have the means of getting the vehicle several feet up in the air, along with either something to lift it or a second pair of hands; otherwise it is a struggle.

Re: Fuel feed issue

The only thing I would add to the good advice given above is to check the filter in the lift pump.
I spent hours trying to get 2478 running after buying Bio Fuel by mistake and it wasn't until we found this silly little filter about the size of your thumb nail located between the feed pipe and the lift pump that we found the cause of all the problems.
We cleaned everything till it sparkled but that stupid little filter was the thing that stopped everything.

My bus number (if any): RML2478

Re: Fuel feed issue

Thanks for everyone's responses. I think the main question I have is how is the fuel pipe attached to the top of the tank? Is it fastened? Is it welded? I know it's not epoxyed.

My bus number (if any): RM187

Re: Fuel feed issue

Rob Olson
Thanks for everyone's responses. I think the main question I have is how is the fuel pipe attached to the top of the tank? Is it fastened? Is it welded? I know it's not epoxyed.

From Roy Gould's post above
There should be an elbow connection brazed or soldered to the top of the tank.

My bus number (if any): RTL 960 RMC 1458, RM 1585 and loads of RTs