Bongo Fury

A while back I joined the forum as a paid up member so i could get info on my broken heater blower. After reading the great fact sheet I soldered up the resister that had failed and job done. Since i don’t use the Bongo every day i needed to check that the fan in the blower was revolving free before setting off each time otherwise the resister would blow again as i figured this was the original cause. The fan would normally be stuck so I would free it and then set off. Well something went again the other day and the blowers wouldn’t work. Did the usual checks and then hooked up the blower motor direct to the battery with cables and it was dead. Time to strip the motor.
Stripping it was not big deal and the cause was apparent right away with the tell tale orange rusty liquid coming out as it came apart. I cleaned the whole thing inside and out using wd40. Once done i put a generous amount of thick lube (high temperature grease) in the bearing ends so the motor core was floating on the grease. Cleaned the springs and the points again making sure the spring where encased in grease. After going over all the innards I put the motor back together and it worked perfectly and much faster than before. Before fitting all the ducting back I gave what i assume to be the AC heat exchanger a good clean with a tooth brush and soapy water as the cooling fins were clogged thick with layers of dust.
Once all back together the blowers are pushing through so much air and at a much greater rate than before. All in all a 3 hour job but a great job done! Off up the Lake District next weekend, another 650mile round trip! Bongo is doing great!

Nice one

daniel wrote:Once all back together the blowers are pushing through so much air and at a much greater rate than before

As I keep saying to those that say the bongo fans are useless, not if they're working right they aren't
Looks like I've got another one to do next week for a mate, got 2 working this way already (one that needed the fan resistors soldering too), got to be better than £150 for a new one
If anyone does have an old dead one laying around, or the fan resistors, it'd be great if you could pass it on to me so I can try & get them going so I've got working spares ready to go & can just do a straight swap next time I have to sort someonoe's out. I don't charge people for doing this, just try & help out where I can.

Had to do the same recently, first tried by spraying loads of WD40, and spray grease into the fan cavity, it worked ok for a day, but then blew the resistor again.

Did the same as you, by striping and greasing etc, and it has been working great since. The only problem is we still get the smell of WD40/grease everytime we use the fan.

As always I wish I had taken pictures of the process but once I get going on something I like to be left alone and don’t stop till its done so didn’t even think about pictures! Next time I do anything I will document it for others!!!!!!!!
Stripping the motor was easy but I was amazed how much dirt, rust and general crap had building up in there. Most was in the base and on the out housing. The coil (spinning built) looked very clean but I guess going round and round will have that effect.
The bottom half of the spindle is such a tight fit into the floating metal ring (for want of a better word, not really a bearing as there are no balls inside!?) that putting thick high temperature grease e in there almost allows the spinning part of the motor to float on the oil with little friction! I actually used a different ouderlosue oil for cleaning, not WD40 that I stated, cant remember what the name was of the product I used.
I’m amazed the fuse or resistor didn’t go again with the amount of crap in the motor causing resistance but now its all loobed up and spinning free!
I cant emphasise enough what a difference cleaning the AC heat exchanges made. It was caked in dust so thick I couldn’t see the cooling fins at all. Only about 30% of the heat exchanger was clear and allowing air through so you imagine how much better the flow is for me now. Faster motor with 70% more clear airflow! Just be very careful cleaning the fins as they are so fragile even with a tooth brush I was aware a couple deformed while cleaning them. Clean side to side along the line of the fins not up and down across them. Use a little lightly soapy water and them Vacume out the crap that comes away.!
Will be taking the bongo to Italy next summer for my wedding. So it will really be tested with the very hot weather in France/Switzerland and Italy at that time of year. I will be up rating the cooling system with additional manually operated fans (one on the radiator and another in the engine bay itself), additional air ducting from the outside to the engine bay and turbo (turbo generates huge amounts of heat that’s could use help dissipating) and an emergency water injection spray for the radiators if all else fails and I need to get to a safe parking space. The water spray trick comes off high performance turbo cars but they use it to cool intercoolers rather than radiators. Will start a new thread for you all when I begin upgrading.
Dan

Daniel wrote: Will be taking the bongo to Italy next summer for my wedding. So it will really be tested with the very hot weather in France/Switzerland and Italy at that time of year. I will be up rating the cooling system with additional manually operated fans (one on the radiator and another in the engine bay itself), additional air ducting from the outside to the engine bay and turbo (turbo generates huge amounts of heat that’s could use help dissipating) and an emergency water injection spray for the radiators if all else fails and I need to get to a safe parking space. The water spray trick comes off high performance turbo cars but they use it to cool intercoolers rather than radiators. Will start a new thread for you all when I begin upgrading.
Dan

This all sounds v. interesting and I'll look out for the new thread and info. Thanks also for the cooling system tips. I'm thinking I should really treat mine to an overhaul. Incidentally, when you talk about high melting point grease, I have some Castrol LM grease - would that be the kind of thing you are talking about and would it do?

One question though: will you not just fit manual over-ride switching to the existing fans? It strikes me as the best/simplest solution.

One things for sure, when its all done you should have the coolest Bongo in town (geddit!)

It all sounds very laudible Daniel upgrading the cooling system, but you've got 3 fans under there as it is, that work fine if the system's up to scratch, IMO you'd be better going over that, replace the hoses & pipes as necessary, rad, stat, check the fan sensor's are working, then it should be fine. We took several bongos down to Italy earlier in the year & were in temperatures up towards 40 celsius, driving up & down the alps with well loaded vehicles, & they were all fine, fans seemed to cut in when they should.
I'm not trying to be a "naysayer", just expressing my opinion I love seeing people coming up with new ideas, but I try & look at all the pro's & cons. Keep us updated on what you end up doing with it.

You are right about the existing system. If its working fine that should be enough. This is not a substitute for an already faulty cooling system, this will be a little extra help. My view is that all systems are a compromise between efficiency and cost so a little extra external air cant hurt anything and will ease the strain on the system just in case it wasn’t working 100%. I think extra fans are probably not needed but manual override switches are a good idea. The fans would still cut in automatically but if you get caught in traffic you can pre-empt the rising engine temperature and turn the fan on right away. A little extra ducting from the front to particularly hot parts such as the turbo is never a bad thing. Water injection? OK that may be a little over the top.
I will have a think and decide what to do closer to the time. Winter is on the way so the cooling is not a priority. Lets hope my heaters work well

Incidentally, when you talk about high melting point grease, I have some Castrol LM grease - would that be the kind of thing you are talking about and would it do?

The stuff I used has a high melting point and hence a high ignition point, well that was my thinking anyway. Since oil and grease are flammable you want it to be as resistant to heat as possible. The motor spins at a very high rpm and would generate lots of heat and perhaps sparks, I didn’t want things catching fire. I also wanted the high melting point so it would stay relatively thick when it got hot still providing good lubrication.


Dan

When I did mine a couple of years ago, If I remember right I just used a small amount of white lithium grease, light thinnish grease, minimum resistance.
In theory, it's a bronze bearing/bush which should be self lubricating ( I think ), but as many of us have found out the motors are moisture traps, they are below the level of the forward facing air intake scoop, so of course any moisture that comes in is going to end up in there, let alone if the drain at the bottom of the windscreen is blocked.
I also enlarged the hole in the plastic casing below the motor to allow any moisture to drain as mine was very small, easily getting blocked. I have noticed on some of the later ones, this hole has been made bigger by Mazda anyway.

missfixit70 wrote:When I did mine a couple of years ago, If I remember right I just used a small amount of white lithium grease, light thinnish grease, minimum resistance.
In theory, it's a bronze bearing/bush which should be self lubricating ( I think ), but as many of us have found out the motors are moisture traps, they are below the level of the forward facing air intake scoop, so of course any moisture that comes in is going to end up in there, let alone if the drain at the bottom of the windscreen is blocked.
I also enlarged the hole in the plastic casing below the motor to allow any moisture to drain as mine was very small, easily getting blocked. I have noticed on some of the later ones, this hole has been made bigger by Mazda anyway.

Good stuff and thanks.

On the issue of fan switches, I like manual over-ride both for the reasons Daniel gives and in case the sensors are old and fail to activate fans in good time (or at all), plus I use my scavenger to reduce heat into the cabin (never mind the higher temp the engine feels uncomfortable at!) and at a lower threshold than it might otherwise operate. Rad fans on manual switch coupled with a Mason type temp gauge would also be to my liking as I could decided when to switch on rad fans, based on temp needle position in case the sensor is slow to activate them when I want.

I like the idea of cooling the intercooler. I'm very interested in what positive impact this may have on engine performance and economy when ambient air temp. is high. Interesting too that the Landie owner (Druid/Dave) who had fitted LPG injection to his Landie, mentioned also that he had uprated his intercooler, and he was getting a huge MPG improvement although he was not sure how much the intercooler was essential in achieving this.

Makes sense that the cooler you can get the intercooler the better. To be honest, I bet most are fairly gummed up & not working at their best. when I cleaned mine out (several paraffin soaks & flushes, then detergent, then rinsed thoroughly then dried out thoroughly) along with all the piping & Air inlet manifold, it was absolutely manky inside.
Difficult to say what difference it may have made mpg or performance wise as I did it at the same time as I replaced hoses, 2 part coolant flush & new stat, which all resulted in it running about 10 degrees cooler, difficult to say for definate about any increase in mpg, but it certainly felt livelier.