About to drain coolant - Urgent advice needed

mikeonb4c · Post by **mikeonb4c** » Mon Mar 12, 2007 9:22 pm

There doesnt appear to be a cylinder block drain plug Dandy. The only one mentioned isa drain plug in the radiator hose upper pipe, and thats the one I didnt remove as part of the official coolant drain procedure. Time was getting on and I couldnt face another 'stuck plug' challenge and thought it couldnt be disastrous if I didnt remove it (I dont think the BF advice sheet mentions it).

I checked my coolant level in the header tank before I left work tonight. It had dropped a bit. As there is no leak (as far as I am aware and I looked over all the joints etc during the engine on/bleed process) I guess it has burped a bit more air out of the system. The workshop manual does suggest this will happen and in fact tells you to repeat 4 or 5 times a cycle of 5 mins at 2500rpm followed by 3 mins at idle. It then tells you to stop the engine, let it cool and then check and top up coolant level as required. I reckon I only did 3-4 cycles (I'd had enough of a diesel engine roaring away in the drive as it got dark) so I guess it is quite natural that air will continue to burp out. Temp gauge is looking v healthy, coming up to temp in half the time it took before thermostat change, and staying rock steady at 11.00 oclock.

Thanks again for all the help - I cant imagine having the confidence to try any of this without BF support. Brilliant. Builds my confidence each time I havea go and (with luck and so far) pull it off.

Peg leg Pete · Post by **Peg leg Pete** » Mon Mar 12, 2007 9:31 pm

When My friends bongo had cooled down, he had to put apprx half a pint of coolant in to top up header tank

mikeonb4c · Post by **mikeonb4c** » Mon Mar 12, 2007 9:34 pm

Excellent Peter - it all 'fits'. With any luck, its another 'job done'

Peg leg Pete · Post by **Peg leg Pete** » Mon Mar 12, 2007 9:35 pm

lets hope so, now you have done it, it will not be a daunting job in 2 years when it needs doing again

Peg leg Pete · Post by **Peg leg Pete** » Mon Mar 12, 2007 9:37 pm

so on the temp guage front, are you getting up to temp in around 5 mins Mike?

mikeonb4c · Post by **mikeonb4c** » Mon Mar 12, 2007 10:39 pm

I reckon so. It was 10 mins prior to that. Since my journey is 10 mins, I now get 50% at operating temp. It was doing this same journey almost every day in the Nissan Sunny that allowed me to me pretty sure about before and after figures. Mind you, to put it in perspective, this journey me be all I do in the Bongo most days. So in cash terms, the difference isnt ruinous. But if you were nipping out now and again throughout the day on short runs, it might add up. In the end though, we know the Bongo is at its best on the open road, chugging along at 65mph, and the end loss (or is it start loss) of a tired thermostat doesnt matter much in that scenario.

bigdaddycain · Post by **bigdaddycain** » Mon Mar 12, 2007 11:04 pm

Hi mike ( and pete

)
I employed a slightly different method when i changed my coolant last summer. After draining the original coolant,i ran a hose to the hot tap, and left it running through the header tank for ten minutes. I balanced the amount of water running through to the amount coming out of the bleed pipe.

Without interrupting the flow, i slowly introduced neat anti freeze into the header tank,till i could see the clear water turning blue.

I had a bucket at the ready with the correct ratio of coolant at hand,and tipped that in the header at the same rate as it was coming out of the bleed pipe... i filled right to the top of the header to give me a second to grab the bung and stem the flow ( getting that bung all the way in is a story in itself!).

This was whilst the heaters were on full heat and maximum speed.

Although my method differs from the manual, my reckoning tells me that the last time any air had been introduced to the system, was when i started to flush clean hot water through 15 minutes previously.

At no stage did the flow of water...then coolant be interrupted in any way,so air COULD NOT be introduced.

I experienced the same thing as you mike,when the engine had cooled, the level had dropped from max to almost minimum

I topped up slowly to max, and haven,t looked back! The level hasn,t dropped a millimetre in 8 months....

I did get the feeling she was warming up quicker though,but i hadn,t replaced the thermostat.
I just put it down to paranoia!

I HATE BLEED TUBE BUNGS WITH A PASSION!!!!!!!!!!!!

mikeonb4c · Post by **mikeonb4c** » Mon Mar 12, 2007 11:30 pm

I gotta admit bigdaddy. thats a novel approach - merits serious consideration. I reckon I let a few pints of new coolant flow out of the bleed pipe into the bucket before I stuffed the bung in (and risked a scalding I think). One thing I share with you is that there were moments when it felt like I needed to be in 3 places at once. I get the feeling that common sense, diligene, and a period of careful watching the system for a little bit afterwards will probably result in a successful coolant change every time. But I can see why a garage that doesnt know Bongos and just wants to get the job done could be risky. Also, if the level drops after they've handed it back to the owner, will the owner notice before it is too late? This could explain some of the problems. It may be that - more or less - Bongos will burp the air out under normal running. The problem comes when the air burped is greater than the volume of fluid in the header tank.

dandywarhol · Post by **dandywarhol** » Mon Mar 12, 2007 11:51 pm

Without worrying you too much, I would be soooooo careful of this airlock/burping malarky - it's just possible it's getting up to temperature so early because the water isn't circulating properly through an airlock...............

francophile1947 · Post by **francophile1947** » Mon Mar 12, 2007 11:58 pm

Better have another beer Mike!! What Dandy says makes a lot of sense if you have only done 10 minute trips.

mikeonb4c · Post by **mikeonb4c** » Tue Mar 13, 2007 12:08 am

I understand Dandy, but everything happened pretty much as described in the manual and as others have described. The temp gauge seems to ease up just as I'd expect. I ran the engine for a total of 40 mins at 2500 rpm yesterday and the gauge stayed steady as a rock. The bottom line though is, if it does have an airlock and given what I've just said, what would I have to do to get it to reveal itself. I'm fresh out of ideas

dandywarhol · Post by **dandywarhol** » Tue Mar 13, 2007 12:19 am

Like I said Mike - not to worry about it - just keep an eye on it, I'm sure it'll be just fine.
I'd be inclined to give it a good long hardish run to purge every bit of air out the system.

mikeonb4c · Post by **mikeonb4c** » Tue Mar 13, 2007 12:38 am

Thanks Dandy. Will do. And presumably sensible to carry some made up 50/50 with me for a bit as insurance

bigdaddycain · Post by **bigdaddycain** » Tue Mar 13, 2007 12:58 am

Good thinking mike

My tub of just in case antifreeze is still in the boot!... still untouched! yay!

Peg leg Pete · Post by **Peg leg Pete** » Tue Mar 13, 2007 8:19 am

I always carry a mix of coolant with me too