Coolant changed, but still bleeding nervous.

[Linusface]

Hi all,
I have had a 1998 4x4 diesel Freda for almost 3 years, without any problems (touch wood) . She has now covered a total of 72000 miles. She has done just over 4000 miles per year since my ownership (Low mileage due to other forms of transport) & passed 3 MOTs without a thing needing doing. Just the routine oil & filter / diff top ups etc. I'm the first UK owner, and without reading the forum, would be blissfully happy & confident with my van . However, whenever I look at this Forum, I get a knot in my stomach thinking I'm sitting on a time bomb . I wish those owners without problems, posted as many comments as those with problems.
Anyway, I have been increasingly nervous about the " Change your coolant every 2 years or else " warnings followed by the " Bleed the system properly or else " warnings. Sort of damned if you do, damned if you don't scenario. My van has shown no signs of overheating and has developed no leaks since I bought her - the coolant has not needed topping up in all that time.
After reading all the bleeding advice (constant flow in & out method, rev & idle method, the squeeze it gently method, see-saw method, even the hang it upside down from the roof of your garage & beat it with a stick method ), I decided to change the coolant.
I drained, flushed & circulated, then drained, back flushed & drained, then refilled with warm water & experimented with the see-saw method (Why do I keep thinking of the Kama Sutra while doing this bleeding job ). Then, when happy with all that, drained & refilled with 50% coolant. I see-sawed again, squeezed, prodded & shook. I got plenty of bubbles & an extra big gurgle slurp when the Thermostat opened & the bottom hose got hot.
I now have Blue coolant instead of Green, no signs of leaks & have done two 10 mile trips, with the temperature gauge staying at 11 o'clock - just as it has for the last 3 years.
Sorry to prattle on, but now for my question - How do I KNOW that I have completed the bleeding process successfully
Do I just suck it & see (with a constant eye on the temp gauge) Or is there a more definitive way of checking Should I re-bleed in a week or so, when she's had a good shakedown, or just leave well alone

PS I wouldn't recommend 'The hang it upside down from the roof of your garage method - that was just a dream.
PPS I'm even thinking of buying one of Haydn's alarms, soon - just to try & get rid of this nagging feeling in the pit of my stomach

[Aethelric]

It sounds fine to me, but you could now see if there is any air by doing a cold bleed (same as normal but cold and without the engine running) - any air in the system will now have collected at the top of the engine.

I used pink coolant when I did it. I reckon the "change the coolant every two years" rule is because that is the life of blue coolant. The pink stuff is good for 5 years.

Of course I may be in the market for a new engine in three years if I've got it wrong

Dave

[haydn callow]

Sounds as though you have "cracked" (no pun intended) it and done a good job. As long as the stat opened and the bottom got hot, job done. Just keep a eye on the coolant level for a few days. When you do fit your alarm it will do that for you every time you start up.
Well Done !!! Have a beer

[Linusface]

Haydn,

I'd love a beer mate, but can't afford one - I'm saving up for one of your alarms

Thanks for the comforting reply - the bottom hose did get hot, so I'll try & sleep well tonight.

[mikeonb4c]

I agree with the above. I plunged in and did mine shortly after I bought it. I used the workshop manual instructions. It was a bit hairy on my own trying to top up the header tank whilst attending to the bleed pipe, now gushing hot coolant (I'll get my son Will on top up duties next time). For a few days I carried some spare 50/50 mix with me and kept the Bongo on short journeys just in case. But after that I stopped worrying. 18 months later the coolant level has not budged one inch. Temp gauge at 11.00hrs every trip. I reckon you've done it right.

But definitely take the pledge and fit a low coolant warning alarm as that is a completely different issue. And, for what it's worth and if you can face it, go the extra mile and fit the Mk.1 (permanent / non ciggie socket installation) and carefully drill a little hole in the instrument panel next to the top end of the temp gauge scale to mount the LED in. Looks neat and very professional and keeps the visual focus on the engine coolant data cluster (poncy term for temp gauge )

[Peg leg Pete]

Well I changed the coolant 2 years ago and now due changing again. I have not fit a coolant alarm, due to regular checking of hoses and coolant levels, my choice, fit an alarm if you so desire

[Aethelric]

drill a little hole in the instrument panel next to the top end of the temp gauge scale to mount the LED in. Looks neat and very professional and keeps the visual focus on the engine coolant data cluster (poncy term for temp gauge )

Oo that sounds a great idea - it's on the list now But then I'll have a switch/indicator location with a redundant hole. Maybe a switch for the scavenger fan? (I won't ask if you think that's a good idea).

Dave

[vanvliet]

Has anyone swapped the rad as a precaution as some have suggested? If so , when the old rad was checked was it choked to any degree ?

[mikeonb4c]

drill a little hole in the instrument panel next to the top end of the temp gauge scale to mount the LED in. Looks neat and very professional and keeps the visual focus on the engine coolant data cluster (poncy term for temp gauge )

Oo that sounds a great idea - it's on the list now But then I'll have a switch/indicator location with a redundant hole. Maybe a switch for the scavenger fan? (I won't ask if you think that's a good idea).

Dave

Yea it was someone else's idea (can't remember who, and it caught on). Don't get your point about the redundant hole though

But if there is one, scavenger fan over-ride sounds like fun

[lizard]

Hi Linusface

Sounds like a good job, excellent. I know the feeling

nagging feeling in the pit of my stomach

[Linusface]

I decided to do another bleeding process, just for peace of mind & got some more air out of the funnel. I don't know whether to be pleased or dissapointed

As for the scavenger fan ........... mine didn't cut in for the entire time the engine was hot & being bled, so I'm assuming it only works when absolutely required.

I, personally, would be VERY wary of putting a bypass switch in

I once had a Renault 20 & the fan temperature sensor failed leading to the engine getting hot. Instead of buying a new sensor switch, I cut the wires & put a manual switch in (Probably saving about a fiver). A couple of days later sitting outside Blackwall tunnel, I noticed the temperature on the rise so proudly switched on my new fan overide. The traffic cleared &, foot down, I set off for Dartford on the A2 70+MPH. A couple of miles on, my dashboard started smoking & the windcreen wipers came on and the radio switched off. Basically the air running through the fan at speed had turned the fan motor into a generator, causing the wires for the fan to cook & melted all the wires of the loom running in the same route into 1 big wire. Being an old car, at that point it became a rightoff. It was quite a laugh though - having the windscreen wipers come on whenever I indicated left, or put my foot on the brake. And when I put the headlights on EVERYTHING else came on at the same time, including the squirters

[mikeonb4c]

I decided to do another bleeding process, just for peace of mind & got some more air out of the funnel. I don't know whether to be pleased or dissapointed

As for the scavenger fan ........... mine didn't cut in for the entire time the engine was hot & being bled, so I'm assuming it only works when absolutely required.

I, personally, would be VERY wary of putting a bypass switch in

I once had a Renault 20 & the fan temperature sensor failed leading to the engine getting hot. Instead of buying a new sensor switch, I cut the wires & put a manual switch in (Probably saving about a fiver). A couple of days later sitting outside Blackwall tunnel, I noticed the temperature on the rise so proudly switched on my new fan overide. The traffic cleared &, foot down, I set off for Dartford on the A2 70+MPH. A couple of miles on, my dashboard started smoking & the windcreen wipers came on and the radio switched off. Basically the air running through the fan at speed had turned the fan motor into a generator, causing the wires for the fan to cook & melted all the wires of the loom running in the same route into 1 big wire. Being an old car, at that point it became a rightoff. It was quite a laugh though - having the windscreen wipers come on whenever I indicated left, or put my foot on the brake. And when I put the headlights on EVERYTHING else came on at the same time, including the squirters

Wow, thats an interesting story and fits with an observation I made on the illuminated switch on my scavenger fan over-ride i.e. the light dims as the fan speed decays, suggesting it is generating voltage while still in motion. But here's the good news:

* I have a separate supply to the fan, no other vehicle wiring involved.
* That supply has a fuse in it, rated hopefully at less than the wiring
* The scavenger fan, like the engine bay itself, sits out of the airflow so is not likely to spin unless powered up.
* If it does spin, the illuminated switch should warn me. Its not come on to date, which is good


So I'm hoping my installation approach is sound. But your tale is a sobering reminder of the importance of being ernest, thats for sure