NZ Bleeding

[Jacobus]

Looking amongst some of the stuff I downloaded last year on bleeding the Bongo was an article by a guy fro New Zealand who bleeds the engine via the temperature sensor at the front right of the engine. Has anybody UK wise tried/used this method and if so does it work. I know folks are always looking for an 'easy' way to do things and having just watched Kirsty bleed a Bongo on Youtube I cannot say I would blame them. It's easy to dimiss something and say there is only one way to do it but experience has taught me that aint necessarily so, but one really does not want to take a chance on cracking a head?..Jacobus.

[missfixit70]

I tried it (in the interests of experimentation) & nearly burnt myself, & I have the egr completely removed giving better access.
It is not designed to be used as a bleed point, it is a tapered fine thread with thread sealer type stuff on it when it comes new, you will more than likely end up damaging the sensor or cross threading it, I couldn't get the damn thing back in quick enough & lost a load of coolant.
Of course you could remove the sensor & replace with a bleed valve as has been discussed on here before, if you've got an alterrnative temp measuring sensor, but I'm not convinced it'd be any simpler bleeding it, you'd still have to get it up to temp to get the stat open to be sure it's doing what it should IMO. I find using the seesaw/funnel method is a good tool to use to see that the system is doing what it should.
If the garage has a vacuuum fill jobby, that should work ok, but it may cause premature issues on other older hoses if they are getting a bit iffy (fairly likely as they'll all be the same age).

[missfixit70]

From what I can remember he, changed tack pretty quickly on that & came up with another method, can't remember if he ever revealed what it was as he seemed to have a bit of an attitude issue The only reason he was trying that was that he didn't have a bleed hose as he had a Ranger type head without that connection. Someone else from NZ had the same issue & ended up Teeing in to the turbo coolant hose to fit a bleed hose with success as I remember.

[teenmal]

Looking amongst some of the stuff I downloaded last year on bleeding the Bongo was an article by a guy fro New Zealand who bleeds the engine via the temperature sensor at the front right of the engine. Has anybody UK wise tried/used this method and if so does it work. I know folks are always looking for an 'easy' way to do things and having just watched Kirsty bleed a Bongo on Youtube I cannot say I would blame them. It's easy to dimiss something and say there is only one way to do it but experience has taught me that aint necessarily so, but one really does not want to take a chance on cracking a head?..Jacobus.

Hi Jacobus,

The guys name was bongonads,he actualy done the bleed Cold by lifting the front of the vehicle,removing the temp sender and letting it do its own thing.Hope this helps.

Cheers..

[missfixit70]

"Bleeding cold" is not bleeding it properly & does not get all the air out, it's a gamble. You may get lucky

[Jacobus]

Ok thanks folks, much appreciated just seemed a weird way of doing it, though hopefully the garage I am going to use here in Portugal will get it right. Taking workshop manual and the FAQ on how to bleed system with me. Fortunately one of the Mechanics speaks very good english so I am sure he will read it as well. If they have internet will point them to the Youtube video as well. Thanks again... Jacobus.

[bigdaddycain]

Might i suggest not "overfacing" your mech with too much info overload Jacobus! There are plenty of methods of bongo bleeding,some seemingly more complicated than others. It's a case of finding out what bleed works best,with minimum fuss.

The reality of the situation is thus... You can replace the cooalnt on one bongo, go through every bleed method known to man, and STILL have an airlock. Others you can replace the coolant, not bleed it at all, run it, with no airlock! They are all different, with different nuances to each vehicle (there's no real explanation to that, that's just seemingly "how it is").

IN MY EXPERIENCE I drop the coolant, flush through with a hosepipe on full blast (everywhere easily accessible) I then refill the system leaving the bleedhose open draining into a container, engine running. (i've yet to try "sleeving" the bleedhose with a slightly larger diameter hose running directly back into the header tank so the coolant "self loops")

With the container method i simply decant the coolant from the bleedhose back into the header, so the coolant is doing a "loop" of the system... Being careful NOT to let the header tank get empty (which is lowering in level at the same rate as the bleedhose is P1$$ing it back out again) You do have to be quite quick. Raising the bleedhose height slows the rate at which the coolant escapes. I try as quick a rate as possible as more air (if any is in there) is expelled better.

After a while the stat will (should ) open and the level seemingly drops in the header, i have some extra coolant at hand to make up for the "drop". That's it pretty much done really! By all means squeeze all the hoses if it makes you feel better

I like to switch on the heaters on HOT from time to time after the stat has opened, this is a very good gauge that there isn't an airlock somewhere waiting to get you! If good, even heat is escaping from front and rear heaters consistantly (post stat opening) then thats a good sign.

TO be doubly certain in the best "Haynes manual" tradition whip the fan sensor plug off if you think the temp gauge is getting too high (removing the plug switches the fans on).

Personally i leave the bongo ticking over post bleed, checking the temp gauge,heater delivery etc,etc. The bongo will not be fully bled no matter which method is employed regardless of what some might say! The level of coolant WILL have dropped by the following day... My personal opinion is that the engine should be left to cool naturally (post bleed) for everything to settle back down again... Any remaining traces of air will naturally rise up into the header as the engine cools, which can often be heard escape as the header cap is released the following day as the cap is released (cold). You'll generally see anything from a 1-3 inch drop in coolant level the day after...The more air was trapped, the bigger the drop! Simples!

I'd always carry some pre-mixed coolant in the vehicle post bleeding, and i'd keep a close eye on the level for a week or so...It's just a matter of being dilligent really....

[missfixit70]

Using the method on the bleed video ie funnel/seesaw gets all the air out if done properly, any drop in level once it's cooled is due to thermal expansion. This can be verified by checking the level hot at any time(be careful if you have to remove the header cap to do this) it will always be higher than the max mark & then cold it will be at the correct level. If it's warm the coolant expands, therefore the level in the header will be higher, hence when I bleed a bongo, it's hot coolant as you finish, so I ususally leave the level in the header half an inch or so above the maximum level, this will have dropped when the coolant cools purely because the coolant occupies less space as it contracts, not because it's not been bled properly. I'm sure somebody into number crunching could verify this if they are bored enough
As long as you understand the method that you are using & understand what the cooling system is doing, you should be ok. if you're not sure try & find someone who is or double & triple check.
As a lot of people have found out, it CAN BE an expensive gamble to mess around with the coolant system if you don't know what you are doing.

[bigdaddycain]

Ok thanks folks, much appreciated just seemed a weird way of doing it, though hopefully the garage I am going to use here in Portugal will get it right. Taking workshop manual and the FAQ on how to bleed system with me. Fortunately one of the Mechanics speaks very good english so I am sure he will read it as well. If they have internet will point them to the Youtube video as well. Thanks again... Jacobus.

Well... if you do a search Jacobus, you'll see many methods employed...Your vehicle, your choice.

I think though that if you find your level has dropped (post bleed) a small proportion of that drop can be attributed to the coolants expansion/contraction... But not to the tune of a 3 inch drop in the header tank level! I have seen this in many bongo's (as i said earlier, all are different from one another). You'll see for yourself after you've bled her up (or your mech has) The proof is in the pudding... (so to speak)

[missfixit70]

I think though that if you find your level has dropped (post bleed) a small proportion of that drop can be attributed to the coolants expansion/contraction... But not to the tune of a 3 inch drop in the header tank level! I have seen this in many bongo's (as i said earlier, all are different from one another). You'll see for yourself after you've bled her up (or your mech has) The proof is in the pudding... (so to speak)

If you're getting a 3 inch drop, then it's not been bled properly or there's an issue, I've never seen a 3 inch drop on a vehicle that's been bled properly.
As I said above, around half an inch variation in level dependant on temperature is within normal expansion & contraction (that I've seen) & will be seen weeks or months after bleeding every time it's up to temperature, if you check the level hot it will be higher due to expansion than if you check it cold - that's simple physics

[westonwarrior]

Ok let's sum up what has been said

There are several ways of bleeding the coolant system on the bongo all will work and none are perfect

After bleeding the level will drop when cooling but excessive drop would mean a problem with the bleed (air still in the system) or a leak..

If its air in the system then it may need another bleed or may just let the air out naturaly via the expansion tank.

It's possible for any one to adequately bleed the system but may not be perfect every time so a little air may escape afterwards.

It common sense to check the levels when cooled or next day and top up as required and keeping an eye on the level regularly just like you do the oil and break fluid etc.


We are all here for the same reason to try and help fellow Bongo owners