Technical questions and answers about the Mazda Bongo
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Ozric
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by Ozric » Mon Jan 21, 2008 11:35 pm
My exhaust has fallen off, the back box bit.
If I fit the new one myself is there any tricks I need to know about or is it a case of take the rest of the pip off and slap the new bits on?
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coco bongo
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by coco bongo » Mon Jan 21, 2008 11:44 pm
My mechanic bodged mine up a bit with weld the last time, but took it apart to do it. It came off pretty easy, but would help if two were on the job to hold it in place. I think he uses exhaust sealer paste of some kind as well.
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cheffy34
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by cheffy34 » Tue Jan 22, 2008 12:17 am
Ozric wrote:My exhaust has fallen off, the back box bit.
If I fit the new one myself is there any tricks I need to know about or is it a case of take the rest of the pip off and slap the new bits on?
Certainly is ozric spray the clampnuts with wd40 chances are they'll be siezed, i've always done my own exhausts save big bucks for not allot of work just back breaking if your doin kirb side mechanics, have had a couple of times that i've had to cut the old pipe and kind of peel it of with a screwdriver or chisel i take mine down me mates workshop now and he lets me do it on his ramp if he not to busy
OH and a big gentle pursauder will come in handy 
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scanner
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by scanner » Tue Jan 22, 2008 12:37 am
The back box on a Bongo is one of the worst bits of design I've ever seen, it has a welded join - a pipe into a muffler end plate - at just the point it flexes the most, it is designed to break.
If (when!) mine goes again I have a length of straight exhaust tubing just slightly larger diameter than the Bongo pipe that will be heated up, forced over the pipe where it levels out after the rear axle and welded tight.
That will then be fixed to the rear mounting points and the back box itself will be a thing of the past.
The noise level is little, if any, louder with a straight through pipe, than it is with a so-called muffler fitted.
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coco bongo
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by coco bongo » Tue Jan 22, 2008 12:42 am
My mechanic says that if mine goes holey again, it will all have to be replaced cos the weld wont take anymore in certain places.
Must be an original one on there, for 60000 miles thats not bad. It was broken in two places hence him having to take it right off.
Best of luck ozric, find a ramp if you can, dont bust yer back. And remember brute force and ignorance, or simply swear at it.
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bigdaddycain
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by bigdaddycain » Tue Jan 22, 2008 8:28 am
scanner wrote:
If (when!) mine goes again I have a length of straight exhaust tubing just slightly larger diameter than the Bongo pipe that will be heated up, forced over the pipe where it levels out after the rear axle and welded tight.
That will then be fixed to the rear mounting points and the back box itself will be a thing of the past.
The noise level is little, if any, louder with a straight through pipe, than it is with a so-called muffler fitted.
I have reservations it will pass the mot like that,even the "big bore" backboxes for the bongo are significantly louder than the standard back box, but probably a fair bit quieter than no backbox at all!
Fair play to you if it pans out ok.....
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scanner
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by scanner » Tue Jan 22, 2008 1:40 pm
bigdaddycain wrote:scanner wrote:
If (when!) mine goes again I have a length of straight exhaust tubing just slightly larger diameter than the Bongo pipe that will be heated up, forced over the pipe where it levels out after the rear axle and welded tight.
That will then be fixed to the rear mounting points and the back box itself will be a thing of the past.
The noise level is little, if any, louder with a straight through pipe, than it is with a so-called muffler fitted.
I have reservations it will pass the mot like that,even the "big bore" backboxes for the bongo are significantly louder than the standard back box, but probably a fair bit quieter than no backbox at all!
Fair play to you if it pans out ok.....
What part of the MOT could it fail? It won't affect emissions and it certainly isn't anything like as noisy as the 500bhp exhausts you get on Scoobies and Corsas these days.
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vanvliet
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by vanvliet » Tue Jan 22, 2008 2:21 pm
I have reservations it will pass the mot like that,even the "big bore" backboxes for the bongo are significantly louder than the standard back box, but probably a fair bit quieter than no backbox at all! ( quote)
Backbxless isnt a lot louder. Diesels do not require the backpressure .Mine passed its MOT recently no problem at all - mechanic said that it was not an issue.I used a length of stainless flexi( so it flexes!) and a chrome end tip attached to the LHS rubber mounting. I might buy a full S/S system eventually but it has been on the van for nine months so far. I also think that it looks a lot better without that muckle box stuffed under the rear

Origo bio stove - no Bongo!
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bigdaddycain
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by bigdaddycain » Tue Jan 22, 2008 2:57 pm
Fair point, but why do mazda/ford fit a backbox in the first place then?
Glad to hear you have passed your mot van...At least i have an option of running a straight through pipe as a temp measure if mine falls off before i can fit a stainless item....
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Ozric
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by Ozric » Tue Jan 22, 2008 3:43 pm
Thanks for all the info but I found a local guy will supply and fit for £145 which seems a fair price and I didn't fancy the job in the current weather conditions anyway.
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scanner
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by scanner » Tue Jan 22, 2008 4:02 pm
Ozric wrote:Thanks for all the info but I found a local guy will supply and fit for £145 which seems a fair price and I didn't fancy the job in the current weather conditions anyway.
Just for the back box?????????
That is WAAY over the top. At least twice as much as it should be.
Buy one from these guys - about £50 for just the back box anywhere should fit it for £20 max.
http://cgi.ebay.co.uk/ws/eBayISAPI.dll? ... :IT&ih=017
I woul;d get the rest of the system looked at as well I thought I just needed the back box, but found the mid section was as holey as a colander as well.
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vanvliet
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by vanvliet » Tue Jan 22, 2008 6:37 pm
No idea why a back box is fitted .
Mind you, my next post might read '' my engine blew up yesterday - - - - -

Origo bio stove - no Bongo!
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bigdaddycain
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by bigdaddycain » Tue Jan 22, 2008 7:15 pm
Sorry, off topic... Just noticed your sig van... You painted your freetop too?....
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vanvliet
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by vanvliet » Tue Jan 22, 2008 10:31 pm
Yep, Hate the grey tops. Took off logos too
Origo bio stove - no Bongo!
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Ozric
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by Ozric » Tue Jan 22, 2008 11:52 pm
Scanner that is cheap!! My problem is that I NEED it fitting tomorrow. I wouldn't care but I check ebay for this sort of thing all the time before I look anywhere else. Must remember that next time.