Identify Pipe help

[surfkernow]

Hello, please could someone help me identify the pipe marked in the photo? I have UV dye in the coolant and my UV torch is showing wet coolant between those two pipes, just a drop, I am not losing coolant but I clearly have a leak escaping from maybe above these pipes?

1996 , 2.5 TD, the pipes are behind the Diesel pump and the photo is taken from under the Driver's seat. Thank you

[JulesMartin]

I think you'll find that they are diesel return pipes going into the rear of the pump and underneath the pump. I think they are to do with the cold start device. you should be able to trace them up to the inlet manifold and one of the 4 solenoids if memory serves me correctly

[surfkernow]

Hi Jules, thank you for your reply. Is there a coolant pipe near the diesel return pipes? I have confused myself on lushprojects searching. I am aware of the main coolant pipe going into the head to the right , but I am trying to see how coolant is ending up trickling on the diesel return pipes. Cheers

[JulesMartin]

Hi, nope the only coolant pipes on that side of the engine are the ones you've already identified. is it possible that the large coolant hose forward of these has a pin hole allowing coolant to spray onto the diesel pipes?

[surfkernow]

Good advice thank you. The hose is one of the many I replaced last year but I will double check as the coolant is coming from somewhere, albeit it is just a drop and it does not drip...the UV torch is catching it at night

Unless of course it is some other fluid that the coolant has mixed with and that is why it is glowing green, oil, diesel etc

[surfkernow]

Actually, I remember last year a Bongo garage found a leak on the water elbow above the diesel pump, maybe this leak is back...i just need to locate the water elbow tomorrow

[surfkernow]

It would appear the leak could be from this pipe , the pipe identified in the first photo in this thread, leads to this junction tap, does anyone know what it does?

[JulesMartin]

I'm fairly certain they are to do with the cold start but certain that none of those small hoses contain coolant. it will either be fuel or a vacuum pipe. Hoses containing coolant will have hose clips on to keep them from blowing off under hot coolant pressure. vacuum hoses don't use clips. low pressure (return) fuel lines don't need clips either usually. I've got to lift the drivers seat tomorrow so I'll have a look around mine and see if I can suggest anything else.

[surfkernow]

Thank you, Vacuum pipes makes sense...it is a little confusing as I re-read my message from the Bongo guy who fixed it last year and it reads :

"Theres a coolant leak on the water elbow 'above' the diesel pump. Its dripped coolant onto the pump. Which explains why you saw the dye on the pump."

I will ping him a message actually, i am just being super careful as I have a new head now, it was diagnosed as a leaking water pump and screwed radiator last time and all have been replaced, but I do check with my UV dye torch every few days to make sure nothing else is leaking

[JulesMartin]

Do you have a coolant level indicator? This may be a better route for you as it will give an audible alarm if the coolant level in the filler tank drops below a certain level. I also have a new head and the coolant alarm and digital thermometer I have fitted keep me up to date with things without having to visually check

[Doone]

The 90° pipe in the photo is a vacuum pipe. Is the coolant blowing back from somewhere like the top engine hose? Or squirting out under pressure from a pinhole in possibly the hose above the starter? Just trying to think what could make coolant appear on a vacuum pipe.

[JulesMartin]

i agree with Doone above this must be spray from a nearby coolant hose. could you run the engine up to full running temperature then lift the seat up with it still running to see if you can see any spray or leaks from the much bigger hoses nearby.

[surfkernow]

Hi Jules, Doone...new head, low coolant alarm, cylinder head alarm, UV dye in the coolant...prior to that, new radiator, water pump, thermostat, new coolant hose pipe set...oh, dye so I can spot any leaks. About to bypass the rear heater this week. I am doing just about everything possible to protect my new cylinder head

I am not losing coolant out of the expansion tank, i check religiously every few days , as i want to make sure my new head does not break. I inspect the van every week at night with my UV torch, whilst the van is on ramps and check for any leaks...the photo above is the only sport where UV dye appears...it does not drip, just a rain drop size of liquid sitting between those two pipes. I have cleaned it off and it is back...

I will double check for leaks on the hose above the starter motor when it gets dark tonight. I now have a pressure test kit, so I can bring the coolant pressure up to 10 psi and check to see if anything is leaking/spraying

It is possible that the last 8 months of Bongo problems have induced Bongo paranoia and madness, something only another Bongo owner whose Cylinder head has cracked, will understand !!!!