Best way to bypass rear heater?

[tallbongo]

Our bongo has got a slow coolant leak, and it's getting worse. I think I've found where it is (pic below).



However, as you can see the coolant pipework around the rear heater is in terrible condition and someones done a non-standard fix already.



We have never used the rear heating, so want to bypass it while getting the above problem fixed. I've read several threads about having done this but can't find any suggestions about the best way. Just blanking off the two T- junctions should bypass the rear heating, but doesn't get rid of much of the corroded metal pipework. Can the outflow from the engine block be connected directly to the front heater input by any shorter route? Has anybody done this? Would it introduce any new potential problems?


(image pinched from Bongo Wikee http://mazdabongo.wikispaces.com/Coolin ... nformation - hope this is ok. If not please let me know and I'll modify post. I'm sure I've seen it on here too, but can't find it.)

[Diplomat]

sometimes I wish that Mr Inamoto had been conversant with the phrase "Keep It Simple, Stupid".

I could live without rear heating, air conditioning (front or rear) and even electric windows.


Frank

[Northern Bongolow]

We have never used the rear heating, so want to bypass it while getting the above problem fixed. I've read several threads about having done this but can't find any suggestions about the best way. Just blanking off the two T- junctions should bypass the rear heating, but doesn't get rid of much of the corroded metal pipework. Can the outflow from the engine block be connected directly to the front heater input by any shorter route? Has anybody done this? Would it introduce any new potential problems?

i cannot make out the position of the first pic, but you can just put a new piece of rubber from the stub above the alternator to the feed pipe to the front heater, no problem, this would by pass the rear heater ok and do away with the need to sort the T piece in the second pic. no ill effects doing this.
you may struggle to find a good piece of pipe to cut back to though as once the pipe is leaking its pretty thin elsewhere along it.

[tallbongo]

i cannot make out the position of the first pic, but you can just put a new piece of rubber from the stub above the alternator to the feed pipe to the front heater, no problem, this would by pass the rear heater ok and do away with the need to sort the T piece in the second pic. no ill effects doing this.
you may struggle to find a good piece of pipe to cut back to though as once the pipe is leaking its pretty thin elsewhere along it.

Hi. Thanks for the reply. I'm afraid I don't understand where you suggest connecting. I spent about an hour earlier trying to identify the hoses. I'm fairly certain my pictures in the first post are in the positions below.



I think the best way for me to do the job may be to blank off this coolant pipe at the point where it joins with the rubber hose (image from passenger side) and also blank off the T-piece fix that heads towards the rear heater.



If I've understood the system properly, this should take out the long metal pipe that is leaking, and allow easy reistatement at a later date if so desired. Does anyone have any comments or helpful suggestions?

[tallbongo]

i cannot make out the position of the first pic, but you can just put a new piece of rubber from the stub above the alternator to the feed pipe to the front heater, no problem, this would by pass the rear heater ok and do away with the need to sort the T piece in the second pic. no ill effects doing this.
you may struggle to find a good piece of pipe to cut back to though as once the pipe is leaking its pretty thin elsewhere along it.

Hi. Thanks for the reply. I'm afraid I don't understand where you suggest connecting.

Ok, I think I understand what you mean now, but would love some clarification.

The leaking pipe is 61-301. I really don't fancy replacing this as it looks like I'll have a fight with the air con pipes in the process. The t-piece fix is on 61-2D1.

I believe you thought the t-piece was on 61-2D2 and were suggesting that I take 61-2D2 out of the loop by connecting directly to the heater with a rubber hose. This would have the same effect as my blanking off 61-213A suggestion, but without the potential downside of air traps.

I think I'd also have to blank off the t-piece that heads towards the rear heater - should be easy enough. At worst I could replace it with a new copper elbow. I really, really don't want to replace this whole pipe having seen this thread http://igmaynard.co.uk/bongo/forum/view ... ilit=pipes - thanks to Matt for the pointer in locating the thread.

Have I got this right?

[Bob]

sometimes I wish that Mr Inamoto had been conversant with the phrase "Keep It Simple, Stupid".

I could live without rear heating, air conditioning (front or rear) and even electric windows.


Frank

Wise words, Mate.

[Simon Jones]

This probably doesnt help with your rusty pipes, but I bypassed mine at the heater end:



Somewhere, I've got a photo from another member who bypassed it at the other end. I'll see if I can find it.

[Simon Jones]

Ok, I've dug this up from an email from a chap called Stephen and I'm afraid I don't recall his forum name. I hope he won't mind be publishing what he sent me, but it may be of some assistance.

Right....looking under the passenger seat you will see a metal water pipe (the end is seen in pics 1 and 2) which goes into about 6" of rubber hose and then back into a metal pipe which goes over to the drivers side,and one of the heater hoses is connected to the end.
Looking under the van on the drivers side (pic 1) you will see a metal pipe with a Tee junction,a rubber hose joins from around the back of the exhaust pipe and the other end goes to the other side of the heater.
Once you are familiar with these two locations you are basically going to join the metal pipe under the passenger seat to the metal pipe under the drivers side floor using,if i remember correctly,16mm INSIDE diameter rubber hose.I can not remember how much hose i needed and i forgot to measure that before,but it is all accessible underneath for you to try the metre you have,i think it should just about do it mind.
On my van the metal hose going from side to side was removed altogether as one end was badly rusted,but for you,i would just leave it in place,it also acts as a hanger for the new hose.
Doing the by-pass this way ensures nice smooth curves on the new hose,rather than trying to join the to ends on the drivers side where the rear matrix pipes take off as the curve would just kink.
I also used a rubber lined P clip to hold the new hose,fixed to a bracket near the centre of the van high up on the floor,the bracket has a thick wiring loom attached to it,i just used a longer bolt to make up the difference.
You will have no trouble feeding the new hose through the fuel pipes,wiring etc as there is loads of room.
This really is a simple process,the key thing is too make sure you familiarise yourself with pipe locations and get it straight in you`re head before you start.

[tallbongo]

Thanks for the pointers Simon.

If I understand correctly both these methods seem to bypass the rear heater, but pretty much using the original route. The first using the original pipe (the one on my Bongo that is leaking) and the second replacing this pipe with rubber. It'd be interesting to know what proportion of coolant leaks are due to actual rubber failure compared to metal failure. Both of the cars where I've had coolant loss have been due to rusty metal pipes. Thankfully I caught this one earlier than my last car where it happened.

I'm starting to lean towards just replacing all the rusty metal with rubber, but keeping the rear heater in the loop, while giving the remaining metal pipes a good rub down and waxoyl. Whatever I decide I'll post on this thread on how it goes.