Blocked rad???

[Kwinpenny]

Hi all,
the cooling on my 1.9D 1Y has always been a bit 'suspect'. Years ago the engine in it when I bought the bus let go, so I sourced a newer 1Y. Since then I've upgraded the pipes to silicon, new water pump and drive belt, new thermostat (and just put in an 80 degree one). Last weekend while doing a service and coolant change I thought I'd put in a new radiator fan switch (the fan works BTW). I was half way through a coolant change and the bottom hose was OFF the rad to aid draining. When I took out the old fan switch the water level would not drop below the bottom of the fan switch threaded hole, even though the bottom pipe was off the rad.....

Given all the other work done, and that I get fed up of checking for the temp gauge to go up (don't we all?), and that even with the pipes off I can only get 4 to 5 litres of coolant in, is it time for a new rad?

For the record I' know the procedure for bleeding the bus as per the wiki and BRICKWERKS instructions. Just after any ideas or a sanity check.

Cheers

[ghost123uk]

I was half way through a coolant change and the bottom hose was OFF the rad to aid draining. When I took out the old fan switch the water level would not drop below the bottom of the fan switch threaded hole, even though the bottom pipe was off the rad.....

and that even with the pipes off I can only get 4 to 5 litres of coolant in,

Just after any ideas or a sanity check.

Ummm I see why you are looking for a sanity check as that is VERY VERY odd.

So when you take the bottom rad hose off water comes out of the rad until it gets to the level of the rad fan switch, then it stops coming out ?

Not being funny but that is against the laws of fluid dynamics so I MUST have misunderstood.

Then you say " and that even with the pipes off I can only get 4 to 5 litres of coolant in" well with the pipes OFF you should not be able to get ANY cooling in as it would all just pour out regardless of the condition of the rad.

Are you sure you are not taking just the top hose off (by mistake) as that would drain about 4.5 Ltr that is coming from the engine and pipes but would not drain the rad much at all ?

If I have misunderstood, kinda re write it so it makes more sense and we will try again.

[Kwinpenny]

Hi ghost,

sorry, to clarify:

once all reconnected, I can only get 4 - 5 litres of coolant back in, after thorough bleeding etc so either there's a blockafe, a furred up rad, or I didn't get all the coolant out in the first place.

On the rad there are two hoses both bottom left corner looking at the front of the bus, one is straight and a few inches above a 90 degree lower hose. It's this lower hose that I took off, and the fan switch (and bleed screw) were out, so yes, in theory it should drain completely.

Hence my question - reckon the rad is pretty furred up? especially as before I had it the water pump was duff so probably not circulating the coolant very well??

Hope that helps.

[ghost123uk]

OK, I cannot recall from memory which is the bottom hose, either way the first thing to do then is take both the hoses off and see what comes out. (I guess it will all gush out). If it does not you could try reverse flushing it, or even better flushing it in both directions, with a garden hose (adapted to stuff up the pipe with rags n tape or similar) If you can then fill (from whichever turns out to be the bottom hose) and it gushes out again on removal then it ain't blocked. I have not come across one that is so blocked it simply sits there not draining at all. (unless perhaps it is stuffed full of Radweld or summat ?) If it won't fill without pressurising your hose connection and / or won't drain fully with both hoses off, then yes a new rad is called for (about £110 for top quality from Brickwwerks)

[Kwinpenny]

Cheers chap, I was thinking of buying a rad to get it here for the weekend, with a long trip looming and this being the only bit of the cooling system not replaced, plus the forums say at nearly 30 yrs old the originals are probably quite gummed up, but I'll try the removal and flush tonight.

thanks again

[mm289]

I would tend to agree with ghost.

I had a lot of probs getting the AAZ in Myrtle to cool properly even after bleeding etc. In the end I disconnected the hoses where they enter the engine bay (o/s) and put a garden hose in them etc. Flushed both ways a couple of times and then bled and it has been perfect since.

I did it that far back incase there was something in the long pipes blocking as well.

FYI, one check I found when bleeding is that you could remove the bleed screw at idle and get no water coming out, if you revved the engine you then got water and its easy to think it is then bled.

In my experience this isn't correct, after flushing the pipes etc I filled up (through the expansion tank not the top up bottle), waited till it had stopped bubbling, then checked the bleed valve and it spurted water even at tickover. It has been perfect ever since.

HTH

MM

[Kwinpenny]

Ok, tonights job, both hoses off, collect coolant, reconnect, then disconnect at engine bay and do the hose flush. Inspect the grot I get out and decide from there, but thanks for the help all...

[Kwinpenny]

FYI, after a flush the rad was still grotty, and once removed found to be pretty poor. 24 hours later and a new rad from Brickwerks was fitted. Same size as the old but SO much lighter - I'm wondering if the weight difference is sediment plus radweld! Anyway, all bled through and 'burped' after a 25 mile test run - the needle now sits on the LED (or maybe even very slightly below it!)

Cheers to all, and, of course, Brickwerks too!