Bongo Fury

help, we have a diesel leak under our bongo - most of the time. the garage replaced the seals on each side. but now he is saying that the leak is coming from the middle of the pump where the injectors are and has asked me to find out if there are seals from this area, he says he will fit, but doesn't have time to source. he doesn't want to touch them until i can find out more.

Not particularly good news. Leakage there is due to an internal seal deteriorating which means removing the pump to fix.

I have reduced the problem to negligeable by cleaning the whole area around the set screws on the rear corners of the pump and putting blobs of wet suit repair glue over the screw heads where the fuel was finding its way out.

Frank

thanks

will pass this on to he who knows

As a temporary measure, put something underneath to catch the drips. a sawn off plastic drink bottle wedges nicely under the pump and won't melt or catch fire.

Others have put some old towel etc in the tray under the engine. It will stay there and absorb a lot of oil. Far better than helping your local motor cyclists off their bikes!

Frank

arranlass wrote:help, we have a diesel leak under our bongo - most of the time. the garage replaced the seals on each side. but now he is saying that the leak is coming from the middle of the pump where the injectors are and has asked me to find out if there are seals from this area, he says he will fit, but doesn't have time to source. he doesn't want to touch them until i can find out more.

If you mean the nut at the centre of the injector pipes then yes there is an O ring behind it that can leak. Ask them is this the nut where it is leaking. (The brass socket above I machined up to remove it.)

thats a handy tip,thanks tgp.

In an ideal world all leaks would be from the 'O' ring shown in TGP's illustration. Then all we would need is the right socket and a replacemet ring.

The diagnosis needs to be preceded by a thorough clean up of the area so that only new droplets are seen when the engine is run. A good light source and a mirror will assist. look for fuel coming out of the screw holes, especially the lower ones.

When all the exterior seals have been replaced the the internal one is left to hold the fort. It might be the main culprit in the first place. It is a good idea to examine carefully where the drips are really coming from before going down the knuckle scraping route. If the pump will have to be removed they can all be done at the same time.

The internal seal is part no 51 in this diagram (lower left area)

http://homepage.ntlworld.com/mike.gough ... 20Pump.pdf

(Link by courtesy of Mikexgough)


Frank

Northern Bongolow wrote:thats a handy tip,thanks tgp.

Indeed invaluable tips... As i suspect a slight untraceable leak on mine ... Though i also suspect it could be my bands VW Passat estate driving bass player that parked in my space while we were away in the Bongo over the weekend...!!

He's had a fair bit of bad luck recently with the Passat & the coolant system on the Golf his partner drives...

thanks everyone, will keep you posted

We're getting 2 bongos a week now with leaky fuel pumps, not the usual case of replacing all the O rings which we do ourselves but internal and gasket leaks, worn drive shafts and worn woodruff keys. These internal bits need real expertise and testing equipment. For this work we use Patterson Diesel in Cowdenbeath, handy if you live in central Scotland, and they are very busy with all sorts of Jap import pumps. The problem seems to be the extreme cold we've experienced coupled with the different properties of Jap diesel....apparently it's not the same as ours and leads to excessive hardening of seals and gaskets. Watch out for wear on the slot in the drive pulley where the woodruff key fits or you're back to square one with a worn drive shaft. Parts are really hard to get now, we just had one needing a drive shaft and delivery was going to be end July but fortunately we had a cannibalised pump with a good shaft so they used that.
So the point is this..don't assume it's just the O rings, it's an expensive enough job doing them alone, check the main gasket for leaks and the woodruff key for damage, or you'll be doing the job all over again .

billibongo wrote:We're getting 2 bongos a week now with leaky fuel pumps, not the usual case of replacing all the O rings which we do ourselves but internal and gasket leaks, worn drive shafts and worn woodruff keys. These internal bits need real expertise and testing equipment. For this work we use Patterson Diesel in Cowdenbeath, handy if you live in central Scotland, and they are very busy with all sorts of Jap import pumps. The problem seems to be the extreme cold we've experienced coupled with the different properties of Jap diesel....apparently it's not the same as ours and leads to excessive hardening of seals and gaskets. Watch out for wear on the slot in the drive pulley where the woodruff key fits or you're back to square one with a worn drive shaft. Parts are really hard to get now, we just had one needing a drive shaft and delivery was going to be end July but fortunately we had a cannibalised pump with a good shaft so they used that.
So the point is this..don't assume it's just the O rings, it's an expensive enough job doing them alone, check the main gasket for leaks and the woodruff key for damage, or you'll be doing the job all over again .

And I'm not a Bongo Apprentice. I'm a Bongo.

Is it the key way in the shaft 12/1 in Franks diagram that is the problem? If so I would simply cut new ones in the shaft. A simple engineering project.

billibongo wrote:We're getting 2 bongos a week now with leaky fuel pumps, not the usual case of replacing all the O rings which we do ourselves but internal and gasket leaks, worn drive shafts and worn woodruff keys. These internal bits need real expertise and testing equipment. For this work we use Patterson Diesel in Cowdenbeath, handy if you live in central Scotland, and they are very busy with all sorts of Jap import pumps. The problem seems to be the extreme cold we've experienced coupled with the different properties of Jap diesel....apparently it's not the same as ours and leads to excessive hardening of seals and gaskets. Watch out for wear on the slot in the drive pulley where the woodruff key fits or you're back to square one with a worn drive shaft. Parts are really hard to get now, we just had one needing a drive shaft and delivery was going to be end July but fortunately we had a cannibalised pump with a good shaft so they used that.
So the point is this..don't assume it's just the O rings, it's an expensive enough job doing them alone, check the main gasket for leaks and the woodruff key for damage, or you'll be doing the job all over again .

Just been through this pain. McAllisters Fuel Injection specialists in Cumbernauld overhauled my pump and although costly, the van is now running like a dream.I asked the question in another thread of how you could be sure replacing the outer 'o' rings without testing the pump and be sure you'ld got to the bottom of it.You've just answered that perfectly.Guess you take your chances by paying for the easier repair and hope thats enough