Bongo Fury

I presume you are talking about the head bolts here.
Over a period of time, the bolts WILL stretch due to the high working forces involved and it is recommended that they are renewed when fitting a new head

I have a query regarding this, i work for an engineering company and everybody i`ve asked says as soon as the metal has yielded it looses its strength. Things like head bolts are usually really high tensile bolts and they torque them to say 3/4 of there working load. Now as a best practise i agree entirely if replacing the head change the bolts for the extra cash its a no brainer, from the engineering perspective i`m curious have mazda really made the bolts so they are that close to failure.
From the third perspective i could be talking out my bum

progroup wrote: One of the things that is causing me grief here is not knowing enough about the Bongo in general. What else is looming in the background, eh? Fortunately for me, I have 5 other vehicles to make do with while fixing the Bongo.

In the main they are simple beasts by modern standards. I little bit of ECU stuff but nothing too fancy. I guess the biggies are:

Overheating/head problems (only happens fora good reason - properly maintinated the engines go on and on)

Rust - got to really keep an ey on that and crawl about poking for signs. Waxoyl (or Dinitrol - dearer but better) whereveryou can

Diesel pump - like all such pumps, a rebuild costs money if you should get problems

Autobox - seems generally very tough and durable but again, a specialist job if it goes

4WD - differentials and viscous coupling. The viscous coupling seems to have a limited life and I'm not sure what you do when it's time is up as I've not heard of people sourcing new replacements. For this reason it is v. important to respect it and ensure you use matched rolling circumference tyres on all 4 corners, to avoid wind up in the system.

Lifting roof - expect trouble sooner or later on old Bongos. But once you've sussed out how it works, and can get 3 people to help you lift it off, it can generally be put right. Avoid using it in v. high winds though, and avoid raising it if you have any extra weight on the roof (roofrack + contents for example).

I'm not one of our guru mechanics so am only repeating what I've gathered. If I've gathered any of it wrong, no doubt one of them will correct me

lazyb5 wrote:

I presume you are talking about the head bolts here.
Over a period of time, the bolts WILL stretch due to the high working forces involved and it is recommended that they are renewed when fitting a new head

1I have a query regarding this, i work for an engineering company and everybody i`ve asked says as soon as the metal has yielded it looses its strength. 2Things like head bolts are usually really high tensile bolts and they torque them to say 3/4 of there working load. Now as a best practise i agree entirely if replacing the head change the bolts for the extra cash its a no brainer, from the engineering perspective i`m curious have mazda really made the bolts so they are that close to failure.
3From the third perspective i could be talking out my bum

If the metal has yielded, then YES it has lost some of its strength. (and this is why the manual recommends checking the length before reusing)
If the degree of yield is within the limit of elasticity for that particular material, then it will return to its original condition when the forces are removed.
1However, if the degree of yield has exceeded the limit of elasticity and gone into the plastic range, then it will NOT return to its original condition. Herein lies the problem because effectively the bolts have stretched and are not the original length. Result is that the bolts are 'loose' and will need tightening back to the specified torque. (I use the term 'loose' VERY loosely here. They are not ready to drop out )
2Yes, the bolts are high tensile and to a very high spec. They wouldn't last long otherwise.
3The bolts will be nowhere near the point of failure IMHO.
and finally, NO, you're not talking out of yer bum. Go back to your guys and I'm sure they will understand what I'm saying.

Getting a bit off topic here. There is a bloke in Canada who is gonna wish he had never bought a Bongo.

poor Dave,
thanks for the explanation thought i was missing something. Does that mean a period check of head bolts is a good thing or would you just keep stretching them. Sorry for the wrong terms i only work there dont understand all the metalurgy stuff.
Did we mention a transmission fluid change and filter clean dave. Its fairly easy thread here http://www.igmaynard.co.uk/bongo/forum/ ... ion+change
Clive

lazyb5 wrote: Does that mean a period check of head bolts is a good thing or would you just keep stretching them.

I've got in the back of my mind that after the head has been removed and subsequently put back (for whatever reason), it is important that the bolts are tightened not only in a specific sequence but also to the correct torque setting. More than one pass is made at a low, then final torque setting - this is to ensure that the head doesn't get 'bent'. After the engine has been run for a period (not sure of period - 1000 miles???), the bolts will need re-torquing, probably due to the head gasket having become slightly compressed. The bolts will not have stretched, just the gasket compressed.
I would think it makes sense to check the bolts from time to time. Doesn't cost anything but a little time. Checked mine a couple of weeks ago and a couple needed tightening slightly.

Dave sounds like a competent enough sort of bloke. If we supply him with enough info on procedures and settings I'm sure he'll be fine. All he needs to do is ask. Tell us what you're short of Dave.

Dave - don't run away with the idea that you have bought a 'pup'. It will prove to be one of the best rides you have ever had.

Thanks Clive & Steve; no worries as I have rebuilt many engines over the years! This is my first Mazda diesel as they do not exist in any form here in North America. Nowadays, with eBay and emailing all over, it is not so difficult nor risky to do this work.

I finally got the head off today around 4PM PST or midnight for you folks! I took enough pics and will upload for the benefit of others. I will include more step-by-step dismantling comments as well. So look for these hopefully by tomorrow.

I was going to do a YouTube video, but my son went on his way with friends, so I was alone and took still shots instead.

Almost every vacumm hose has crytalized and breaks into your hand upon removeal. Cylinders 2,3,4 look perfectly normal running clean. #1 is the culprit though. White deposits tell the story plus a different shade of black soot on the piston compated to #2, 3, & 4.

I was not able to break to torque on the Camshaft bolt. Instead, I left in place for bench removeal. BTW; this saves time! Review my pics later. So, having backed off ALL pressure to the values by backing off each tapet adjuster screw, I then was able to safely remove each head bolt. I broke an impact reducer and a 9/16 12 point socket while removing some of the bolts. I need the head tightening specs for torque and sequence!

I will be replaceing ALL hoses, clamps, timing belt and adjuster [why not while apart!]. Water pump appears okay, bearing and shaft are fine, no visable leaks. Should I replace the water pump anyway??? Is anything required to do on the intercooler system???

Injectors appear okay at first blush, but I will dismantle, clean, and calibrate - need tech info here!

I will dismantle the rest of the head tomorrow on the bench. Must have it stripped down for the machine shop come Tuesday morning. Meanwhile, I will make a list of the parts required and likely give the business to JAS unless there are better sources out there. I would like to know what parts to stay clear of. I would prefer OEM, but help me to avoid Chinese built stuff, they still have crude manaufacturing practices. Any suggestions???

That's all for now, being hailed to get the barbie-q fired up!
Cheers,
Dave

Hi Dave
Water pump leaks - Take a look at this
http://www.igmaynard.co.uk/bongo/forum/ ... =3&t=47381

2.5 diesel
I have got the head and camshaft assemblies complete with torque settings and sequences (pdf format) ready to send.
Slight problem though - I need your email address. Send it by pm.
I'm off on holiday in about 6 hours and the boss aint gonna hang around.

progroup wrote:This is my first Mazda diesel as they do not exist in any form here in North America.

There are certainly some diesel B2500 Mazda Pick-ups over there as a friend of mine in New Haven, Conn, has one - not sure if it has the WL-T engine though, I'll try and ask him when I can.

progroup wrote:Thanks Clive & Steve; no worries as I have rebuilt many engines over the years! This is my first Mazda diesel as they do not exist in any form here in North America. Nowadays, with eBay and emailing all over, it is not so difficult nor risky to do this work.

I finally got the head off today around 4PM PST or midnight for you folks! I took enough pics and will upload for the benefit of others. I will include more step-by-step dismantling comments as well. So look for these hopefully by tomorrow.

I was going to do a YouTube video, but my son went on his way with friends, so I was alone and took still shots instead.

Almost every vacumm hose has crytalized and breaks into your hand upon removeal. Cylinders 2,3,4 look perfectly normal running clean. #1 is the culprit though. White deposits tell the story plus a different shade of black soot on the piston compated to #2, 3, & 4.

I was not able to break to torque on the Camshaft bolt. Instead, I left in place for bench removeal. BTW; this saves time! Review my pics later. So, having backed off ALL pressure to the values by backing off each tapet adjuster screw, I then was able to safely remove each head bolt. I broke an impact reducer and a 9/16 12 point socket while removing some of the bolts. I need the head tightening specs for torque and sequence!

I will be replaceing ALL hoses, clamps, timing belt and adjuster [why not while apart!]. Water pump appears okay, bearing and shaft are fine, no visable leaks. Should I replace the water pump anyway??? Is anything required to do on the intercooler system???

Injectors appear okay at first blush, but I will dismantle, clean, and calibrate - need tech info here!

I will dismantle the rest of the head tomorrow on the bench. Must have it stripped down for the machine shop come Tuesday morning. Meanwhile, I will make a list of the parts required and likely give the business to JAS unless there are better sources out there. I would like to know what parts to stay clear of. I would prefer OEM, but help me to avoid Chinese built stuff, they still have crude manaufacturing practices. Any suggestions???

That's all for now, being hailed to get the barbie-q fired up!
Cheers,
Dave

This is going to be an interesting thread to track. Good luck and keep us posted.

Sent email of torque settings - Did you get it????

Yes, I received the invaluable head/camshaft specs. You folks are great and I must commend you all for taking time out to help out!

The Bongo job has brought me some new pain; the type dealing with my 'muscles' and 'back' pain! Ha Ha!

From a mechanical perspective; very easy vehicle to work on. I recommend complete removal of the front passenger seat assembly as part of the preparation process. Also, removal of the back cover to expose the rear of the head is necessary to better access the EGR pipe and other bolts. See my pics on a later post regarding this.

Removal of the Turbo Charger system gives far easier access to other components for replacement or inspection. I am very tempted to remove and inspect the oil pump cover and filter assembly simply because it is easy to do at this stage. Any suggestions??? Oil Pump issues with these dieesel by chance???

All in all there are only 3 or 4 hard to reach or 'sneeky' bolts/nuts to remove - otherwise fairly straight forward.

Cheers,
Dave

progroup wrote:Yes, I received the invaluable head/camshaft specs. You folks are great and I must commend you all for taking time out to help out!

The Bongo job has brought me some new pain; the type dealing with my 'muscles' and 'back' pain! Ha Ha!

From a mechanical perspective; very easy vehicle to work on. I recommend complete removal of the front passenger seat assembly as part of the preparation process. Also, removal of the back cover to expose the rear of the head is necessary to better access the EGR pipe and other bolts. See my pics on a later post regarding this.

Removal of the Turbo Charger system gives far easier access to other components for replacement or inspection. I am very tempted to remove and inspect the oil pump cover and filter assembly simply because it is easy to do at this stage. Any suggestions??? Oil Pump issues with these dieesel by chance???

All in all there are only 3 or 4 hard to reach or 'sneeky' bolts/nuts to remove - otherwise fairly straight forward.

Cheers,
Dave

The way I look at it, an opportunity to crawl over all the ageing systems of a Bongo and replace/renew/repair anything that looks worn, is an opportunity not to be missed (though limited by the size of your wallet of course) once you've got a load of stuff removed anyway to give access for a major job. You sound well up to getting this Bongo running sweet as a nut over time, and a well sorted Bongo is a great drive, in my oipinion, and worth any effort you care to invest in it. Maybe you could even slip into importing the odd one, fixing up it up and turning other Canadians on to them.

how can I post attachments [all pics showing the head removal!]?

This should help - http://www.igmaynard.co.uk/bongo/forum/ ... m.php?f=42 - basically you have to host the pics on an external site such as photobucket/Flickr/etc then copy & paste the IMG links into the thread.

missfixit70 wrote:This should help - http://www.igmaynard.co.uk/bongo/forum/ ... m.php?f=42 - basically you have to host the pics on an external site such as photobucket/Flickr/etc then copy & paste the IMG links into the thread.

Okay; can you try this link showing ~50 pics pertaining to this thread or post topic?

http://www.dropbox.com/gallery/11334027 ... S?h=1c82ff

Let me if it works for you... PS they were uploaded to my 'DropBox' website FYI!