Club 80-90 Forums

Hi. Just wondering....
What do the small rubber hoses do that link the injectors?
I had one split & bus wouldn't start.

Also I have clear fuel pipes going from filter to injector pump, & back again ( ) I can see what looks like little air bubbles in them. Is this normal? Appears to have no side-effects.

The little rubber hoses are for the return of excess fuel.

I would imagine that a leak in them would introduce air into the system.

Injectors have a set presure that they inject at, but the pump doesn't always diliver this threshold throughout an injection (ie before and after). The spillback hoses are there to alow the runoff back to the tank, they can carry a significant volume of diesel when the engines running, you'd certainly notice the leak! The pump has a leak off hose too for simular resions, which goes back to the tank via the fuel filter. It goes through a thermostat alowing it back to the tank when the fuel filter is warm, or into the filter if its cold, alowing it to heat the fuel filter when cold thus preventing filter waxing (Spillback is warm as its had pump work done on it).

Though this filter arangement is pritty neat, aparently its not uncommon for it to let in air around the thermostat if its not spot on, which can make starting slow (it has to self prime the air out by curning over on the starter) or can cause fuel starvation. Might be worth double checking the seals on it if theres lots of air around, the odd bubble I wouldn't worry so much about. If you've got some water in the fuel lines that can look like bubles too. The fuel filter has a water drain tap on the bottem - drain it into something and leave to settle - you'll see any water if its there, its part of the service scedule anyway as tanks can colect small emounts of moisture.

Cheers for that full & understandable reply.
I thought it must of been air as it was along the top of the fuel pipe. Wouldn't water be at the bottom?
Anyhow rubber hose it now back on & is much better.

I certainly did notice/smell the diesel loss, At least it wasn't yet another injector pipe as I'd first thought!