Checking coolant levels - without the stick!

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Checking coolant levels - without the stick!

Post by BackinaBX »

Hello again forum,

Because I've only just bought my shiny BX, I am of course spending too much time going over it finding out how stuff works and checking everything. Already discovered that there was about half a pint of oil in it - now rectified, and if it ever stops bl~~~y raining I'm going to give it a service.

However, I want to check the coolant level. Haynes says that there should be a tube inside the header tank on the radiator, and that it should be wet up to the threaded part. I don't have one... for whatever reason that may be. So I'm guessing I could stick some pipe, or some doweling wood into the header and read off the depth of the coolant...

So, after this long winded post, I'm sure you all know what I'm asking.

How deep should the coolant be.

Oh yeah. 1.9D


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Post by AndersDK »

Never seen one of those level dipstick tubes in real life. Dont know if they were exclusive items only on certain markets. Like coolant drain taps on radiators and engine blocks - never seen these either but Haynes still refers to them as facts on all cars ...

The coolant level would be some 6-8 inch down the filler neck in the raditor - or the level in any fitted expansion tank some 3 inch down - on cold engine.

If still in doubt - simply top up. Then the system will self level by expelling too much fluid when engine is hot. That is because the coolant fluid mostly consist of water - which expands quite a lot when hot. The excess fluid is expelled thru the cap as this contains a pressure valve. This valve also ensures that the system is never pressurised to more than some 1-1.5bar
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Post by sleepy0905 »

What you mean one of these tubes

And both my bx have taps on the block and the radiator for draining.
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Post by DLM »

Anders - as ever - has a very practical suggestion. Forget about the level tube and drain/flush the cooling system for the sake of your peace of mind.

Now tighten up drain taps/bottom hose, fill up with a stronger-then specified anticorrosive/antifreeze mixture until it's close to the top of the radiator with bleed taps opened until they start to overflow. Tighten up bleeds and then top up with deionised water, using a home-made 2litre cut-off soft drinks bottle "header tank"to apply constant header pressure, and run engine for a good 20 mins at least with the filler cap corner of the car in upmost position on a slope.

Make sure you massage the top hose for a good part of that 20 mins and watch the bubbles appear both though flowthrough and your top-hose squeezing as you "burp the BX" - to use Anders' phrase. Some additional bleeding may be required.

Once the levels have stabilised, with the impromptou, water-filled header tank still in place, and when the 20mins or so are up, switch off and leave to cool. Once the system has cooled, remove the header, and replace the rad cap (a new one, only a couple of quid, acts as additional peace of mind).

Now run the car normally for a few days. Don't get worried about some water being dumped out of the rad cap overflow. Eventually, the coolant level will settle down to a equilibrium state: no further top-up should be necessary. Just for the record, I picked up this procedure from a Citroen/Peugeot-trained mechanic while in a state of post-head-gasket -replacement paranoia. Though the car dumped water from the rad-cap-overflow as described for a few days, it reached the no-further-loss stage, and then ran sweetly for another 40k miles.
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Post by Way2go »

DLM wrote:top up with deionised water
:?: Why deionised :? I understand that distilled is necessary in Batteries but normally tap water mix for Anti-Freeze. Any calcium deposits from the water can be removed by Barr's flush at a convenient future change of Anti-Freeze.
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Post by AlanS »

If you do a Ph test on water from the tap, in most cases it's acid in content and out here anyway, salt is also in there as well, and acid in a mix of metals in particular copper and alloy usually = electrolysis.
A large fridge company over here did a test on a fridge a few years back and due to our climate, their mix of metals and the water via condensation within the insulation making contact, rec kon they found 39 volts of static had built up in the system within 72 hours. It was common knowledge in the trade but never made public.
There is also a theory that stray volts being conducted through the mechanicals of any car coupled to faulty earths also can tend to cause increased corrosion via the same source.

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Thanks chaps

Post by BackinaBX »

All good advice... thanks. I've checked the levels, and as suspected, it was low, so I filled it up and it did blow a bit out the top of the rad, but all is well now.

Talking of flushing the cooling system, and subsequent refilling, I take on what you say about distilled and deionised water, but won't it cost a huge sum of money to fill the whole cooling system with this?

Also, as we're under the bonnet, what make of oil would you suggest. When I needed to top it up in a hurry I bought 5 litres of 'High Quality' 15/W40 from Wilkinson's... oh yes, 5 litres / £8. I don't plan to use this gunk for the main oil change, of course.
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Post by Oscar »

Hello there

welcome to the club.

Tom Sheppard has done a very good write-up on the procedures you need to carry out after buying your BX. ONe of those is a flush of the cooling system, replace cap, replace bottom hose, backflush radiator etc.

Unfortunately I can't find the write-up anywhere or I'd have put the link in. Does anyone else know where it is? (Not over on old Andyspares is it?)

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Post by M »

Oscar wrote:Unfortunately I can't find the write-up anywhere or I'd have put the link in. Does anyone else know where it is? (Not over on old Andyspares is it?)

Sadly yes it was, though there is still some usefull info to be gleaned from going back through the "ramblings".

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Post by Bluey1978 »

I always use de-ionised water as down here in Suffolk the water is so hard you get threatened everytime you turn the tap on :lol:

So i'm hoping that by using de-ionised water the chances of the water channels getting blocked with limescale will be minimised. The local stores down here sell it dirt cheap aswell and in 5 litre containers, or you can 'bottle' your own if you have a home condenser.

When I put my new rad in I made sure that the strength of the coolant was bang on and that it was all de-ionised water - the whole system was flushed out and that included the use of the WYNNs cooling flush.

The HAYNES BOL was a bit out on the quantity of water aswell, mine took very nearly 8 litres of antifreeze solution.

Mines all sorted now, though bit pi**ed off with the price of a new Temp sensor as it came in at nearly £28, for a lump of copper, though the Cit bloke did say drop the level indictaor in a cap of Cillit Bang (or vinegar) in order to clean up the contacts as apparently these NEVER fail as they just complete an electrical circuit through the water - so if you have none the light comes on - simple yet effective.

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