Bongo Fury

I was flushing and replacing the coolant on a fellow bongonauts ride and we discovered the rear heater was bypassed. Someone had used one of the hoses to connect the two steel pipes, missing out the heater. I know this is not a problem as some people would do this on purpose. The problem was that the pipe was kinked which was either blocking flow or at best restricting it. I was able to cut the hose shorter in order to form a better path between pipes and remove the kink. When flushing the rest of the system there was no rust even though there was just water in there, no antifreeze. When i flushed this bit there was loads of brown gunk. Would this kink have caused any problems with the flow to the head.
Also when Bleeding and getting up to temp i never once heard the fans kick in. I disconnected the switch and they work, think the switch is done for. How can i test and where can i get a new one?

Kinked rear hose shouldn't be an issue, when I removed mine, I didn't put a loop in at all, just blanked both ends, doesn't need a loop (as per the lushprojects pics of the front only system) .
How hot did it get? fans only kick in at @96 degrees at the top hose, which equates to roughly 3/4 of the temp gauge scale on mason/modified.
Test the 2 pin temp switch in a pan of water with a thermometer & multimeter reading resistance, keeping the electrical side out of the water
at 20 degrees, resistance - 2.0 -2.9
at 80 degrees, resistance - 0.27 - 0.37

Thanks for that. Is the end of the switch in the water jacket?(need bleeding again)

yes tony it is, and be carefull with the end plastic bit, its bonded onto the brass bit, if its wobbly chuck it away.
they are £36 from mazda, dont use a copy part either.
in my opinion its best to keep the rear flow unkinked and working, so you did the right thing, as this heater ciruit flows through the stat housing, and makes the stat work better.

Yes it is - when I replaced mine I was luckly just around the corner from Wheel Quicks. I would try the likes of Jas, Bongobits or do they sell them in the shop ?

Northern Bongolow wrote:yes tony it is, and be carefull with the end plastic bit, its bonded onto the brass bit, if its wobbly chuck it away.
they are £36 from mazda, dont use a copy part either.
in my opinion its best to keep the rear flow unkinked and working, so you did the right thing, as this heater ciruit flows through the stat housing, and makes the stat work better.

It's in parallel with the front heater circuit, not in series, so it has no effect on the stat whatsoever whether it's flowing or not, it still controls at the same temps etc, blanked off is how they come out of the factory if they've only got the front heater fitted
Mine's been running fine for the last year with rear heater complete removal & blanking (head went last summer, nowt to do with rear heater removal though, before anyone starts down that route ) Temperatures are exactly the same & it bleeds up the same as any other, coolant capacity is only reduced by @600ml with all the pipework & matrix removed.

Would the switch not be below the height of the expansion tank? Therefor remove switch, put thumb over hole and then replace. Else pressurise expansion and do it??

thedogsbollox wrote:Would the switch not be below the height of the expansion tank? Therefor remove switch, put thumb over hole and then replace. Else pressurise expansion and do it??

Wouldn't it be better to take the cap off the expansion tank? Otherwise the only way to replace the volume of lost water will be by sucking air in through the opening created by removing the switch.

Not that that's likely to be a huge amount if the Dutch boy is quick with his finger.


Frank

thedogsbollox wrote:Would the switch not be below the height of the expansion tank? Therefor remove switch, put thumb over hole and then replace. Else pressurise expansion and do it??

Have you seen where it is? No chance but good luck trying, just don't cross thread or snap the new switch trying it. You'll probably end up losing all the colent down to that level TBH, better to drain it off into a bucket to reuse if it's new & worth saving, then you can do the job with no loss & no stress.