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Draining de coolant

Posted: 08 Aug 2009
by mnde
I'm going to ask on here as it's [tumble] on BXC today

Where exactly is the inlet manifold drain plug on a BX16/19 and is it *imperative* to remove it when draining the cooling system? Haynes BOL tells me to remove it at the same time as I loosen all the bleed screws... but there's no picture of the actual location, just a simple schematic diagram of the cooling system where it's arrowed next to the water pump... I've looked and I can't find anything obvious.

I've got some time tomorrow morning to do it, but if it requires ramps, forget it I ain't got none.

Cheers,

Mark.

Re: Draining de coolant

Posted: 08 Aug 2009
by Philhod
:? I've done 1600 petrol and 17TD / 19 N/A diesels. Drained and refilled without disturbing the
object you mention.

Even some of the exotic 70's/80's stuff I had, with water heated manifolds (x flow's), I didn't bother to drain, unless I was taking the head off and then only to save water going everywhere.

Re: Draining de coolant

Posted: 09 Aug 2009
by docchevron132
Ahhhh, now..

Erm, no, entirly not required at all, and I suspect you'll find that unless you have a stupidly early engine in your car, it wont even have a drain on the manifold.

If it has got one, then it'll be a 12mm brass plug pretty much directly under where the return pipe is attached to the manifold.
But I'd be amazed if yours has it.

Even if it has, dont fucking touch it, chances are it'll snap off after you've turned it through about 180deg and leave you with a leak you cant stop...

Re: Draining de coolant

Posted: 09 Aug 2009
by mnde
Right, I've drained and refilled with tap water and Holts Speedflush (because I daren't try shifting the thermostat bolts and can't be bothered to undo the matrix hoses to flush out manually). Filled till overflowed, tightened bleed screws when water ran out blah blah.

Then started the engine, let it run at fast idle until fan kicked in and out, then for 10 minutes as per Speedflush instructions.

Being lazy, to achieve fast idle (I chose c 1200 rpm) I turned in the throttle stop screw. Only now, after the 10 minutes have elapsed I've undone the screw loads and the idle shows no sign of dropping.

What's happened? Is it because the choke hasn't come fully off and the fast idle stop is preventing the lever from contacting the throttle stop screw........ could this be an issue with the waxstat coolant hoses being at highest point of system etc etc. If so, what do I do??

Currently left it to cool down before I drain and refill again.

Cheers,

Mark.

Re: Draining de coolant

Posted: 09 Aug 2009
by Way2go
mnde wrote:idle shows no sign of dropping.

What's happened? Is it because the choke hasn't come fully off and the fast idle stop is preventing the lever from contacting the throttle stop screw........ could this be an issue with the waxstat coolant hoses being at highest point of system etc etc.
Mark.
It must be that your butterfly(s) are not closing properly and are admitting too much air. Possibly some crud in the airway has dropped into a position to cause this, it only take a small bit. Alternatively the linkage through the carb body is slightly stiff through lack of oil.
Apply some thin oil (3in1) to the linkages on the butterfly body, restart and blip the throttle a few times and see if it settles down. :D

Re: Draining de coolant

Posted: 09 Aug 2009
by Philhod
[chin] Lubricate by all means but this time don't mess with anything, just let it warm up at normal tickover. Don't forget to put 30% all year round coolant additive in, unless you fancy doing it again in a couple of months. :)
If tickover returns as normal, fine if it doesn't, now's the time to check that out. :wink:

Re: Draining de coolant

Posted: 09 Aug 2009
by docchevron132
Wind it off, let it cool right off, then start it up and allow to reach temp at normal idle.
You'll almost certainly find that there's still air in it, they can be a bit of an arse to get it all out, best way is to pressurise the system, if you dont have a tool or modded cap, then run it up with the rad cap on and use system pressure to bleed the bleeds until the fans cut in.
Although obviousley wear gloves or summat since hot water can burn and all....

Re: Draining de coolant

Posted: 10 Aug 2009
by Way2go
docchevron1472 wrote: Although obviousley wear gloves or summat since hot water can burn and all....
[Anorak Mode] If the pressure cap is venting then the water is hotter than 100 degrees and the spurt that results when you release the cap is the sudden boil that results as the water falls to 100degrees under atmospheric pressure. [/Anorak Mode] [coat]

Re: Draining de coolant

Posted: 10 Aug 2009
by mnde
Success!

I drained the water and speedflush out, and this time round when filling up I followed Jon's instructions on BXClub DIY page which I found very useful: i.e. while slowly filling up just open one bleed at a time, starting with the one furthest away from the bleed point, until water flows out of it, close, move to the next one. Then once full, leave the rad cap OFF, start engine and run at fast idle, bleed each point in turn again until a stream of water appears with no bubbles. Run for a while until fan kicks in, top up as necessary etc.

Should be sorted, yeah? Or do I need to bleed again with the cap on just to be sure? There was a fair spray from each of them. The rad seemed to be hot all over, and the auto choke operated as normal this morning.
Philhod wrote:Don't forget to put 30% all year round coolant additive in, unless you fancy doing it again in a couple of months. :)
If tickover returns as normal, fine if it doesn't, now's the time to check that out. :wink:
Yep, I put 1.75L of coolant additive in :wink: , plus a little more for luck to account for losses while bleeding. It's orange this time instead of blue. And yes, I used distilled water, not the crap from the tap this time round. The tickover is back to normal now too.

I got a lungful of steam and coolant when I was bleeding the point near the heater matrix hoses, as it squirted straight onto the exhaust manifold *cough cough*. The thermostat bleed was a little tricky because the method of bleeding was basically removing and replacing the blue rubber bung (That's still on the "to do" list). More difficult with the engine running and a hot stream of coolant firing out :lol: (No gloves BTW, I was just careful as possible)

I topped up again this morning before leaving for work, and there don't seem to be any leaks so I think it's all good! One more question - where does the other end of the bottom hose attach onto. I couldn't see, working from above. Yes, I undid the bottom hose connection from above. Luckily the jubilee clip had a 7mm hex head, but I got scraped arms for my troubles. Par for the course with Citroens of course :lol:

Mark.

Re: Draining de coolant

Posted: 11 Aug 2009
by docchevron132
Sounds like a good un to me.
Just keep an eye on the level for a couple of days.
Erm, one end of the bottom hose goes to the rad, the other goes to a block on the back of the engine which you can see above the driveshaft..

Re: Draining de coolant

Posted: 11 Aug 2009
by Philhod
But be extremely careful when connecting / disconnecting from here. It's a throwback from the mk one, used to be a fuel heater, but is now just a plastic junction....................................


......That fucking cracks. :x

Re: Draining de coolant

Posted: 12 Aug 2009
by docchevron132
Yes, it's rather habitual at remving the bottom hose port, with the bottom hose!

Cheap enough for a shiny new from Citroen though, and they keep them in stock, which I suspect says rather alot about how many snap!

Re: Draining de coolant

Posted: 12 Aug 2009
by Philhod
:lol: :lol: I thought it was just me being a clumsy cunt. I've managed to bust 3 up to now and that top bolt is a bastard to get at. :x

Re: Draining de coolant

Posted: 12 Aug 2009
by docchevron132
nah mate, it's the plasticrap they use in manufacture, from the same family as cheesium and crapite!

Re: Draining de coolant

Posted: 12 Aug 2009
by mnde
Ah ok, I just wondered where the other end connected when I was waggling about the radiator end, trying to get it back on to the stub.