Another Question About Coolant Bleeding

[bigdaddycain]

I up until VERY recently adopted the old "heaters on full blast" technique... This worked well, as TGP said, it proved a convenient method of monitoring for airlocks at the matrix', especially the notorious rear matrix! If in a hurry though, i'll in future knock the heater fans on here and there to check for good heat periodically... As is common knowledge, the most important aspect of bleeding the good old bongo is getting that darn stat to open, once that has been acheived the bongo pretty much bleeds itself! Having the heaters on whilst trying to get the coolant to exceed 82 degrees will take longer. I factor in an hour to an hour and a half to bleed a bongo, maybe not the quickest, but certainly the safest most effective way. (better safe than sorry) I'm with you Mike (exgough) A visual inspection of coolant level is required at least 3 times on cold start ups as your man Masabee rightly points out. With an amount of pre-mixed coolant to be carried on board at least for a few days after bleeding.

[dandywarhol]

[Aunt Trumpet]

I up until VERY recently adopted the old "heaters on full blast" technique... This worked well, as TGP said, it proved a convenient method of monitoring for airlocks at the matrix', especially the notorious rear matrix! If in a hurry though, i'll in future knock the heater fans on here and there to check for good heat periodically... As is common knowledge, the most important aspect of bleeding the good old bongo is getting that darn stat to open, once that has been acheived the bongo pretty much bleeds itself! Having the heaters on whilst trying to get the coolant to exceed 82 degrees will take longer. I factor in an hour to an hour and a half to bleed a bongo, maybe not the quickest, but certainly the safest most effective way. (better safe than sorry) I'm with you Mike (exgough) A visual inspection of coolant level is required at least 3 times on cold start ups as your man Masabee rightly points out. With an amount of pre-mixed coolant to be carried on board at least for a few days after bleeding.

Hmmm,... Sorry but I thought that it was now widely accepted that it is virtually impossible to get the bottom hose warm whilst it is sat on the drive. In the extremely loooong coolant thread recently I thought that it was considered that the system is (in very basic terms) split into two parts and that to get the stat to open pretty much requires a very long run and/or mild weather, thus getting the engine to work harder. In cold conditions and short journeys the stat may not open at all. Is it not more important to get the heaters hot , indicating that there is no air in the "small" part of the system?

[haydn callow]

I have bled about 20 Bongos to date and all were done on the driveway with no "going for a run" the last one was 3 weeks ago and the temp was minus 4C...It took the normal 40 mins.

[Doone]

I thought that it was now widely accepted that it is virtually impossible to get the bottom hose warm whilst it is sat on the drive. In the extremely loooong coolant thread recently I thought that it was considered that the system is (in very basic terms) split into two parts and that to get the stat to open pretty much requires a very long run and/or mild weather

My husband has succesfully bled hundreds (thousands??) of these - I don't know exactly what he does, but I do know that none have needed a long run during the bleed procedure.

I'm with you Mike (exgough) A visual inspection of coolant level is required at least 3 times on cold start ups

Keeping an eye on the coolant level for a few days sounds about right.

[dunslair]

yep.. since our coolant was changed a couple of weeks ago I have developed OCD (obsessive coolant disorder) I check it every morning to make sure it has'nt gone down (no smutty comments please) and I have to stop myself from checking it before I go to bed as well

[Aunt Trumpet]

I thought that it was now widely accepted that it is virtually impossible to get the bottom hose warm whilst it is sat on the drive. In the extremely loooong coolant thread recently I thought that it was considered that the system is (in very basic terms) split into two parts and that to get the stat to open pretty much requires a very long run and/or mild weather

My husband has succesfully bled hundreds (thousands??) of these - I don't know exactly what he does, but I do know that none have needed a long run during the bleed procedure.

I'm with you Mike (exgough) A visual inspection of coolant level is required at least 3 times on cold start ups

Keeping an eye on the coolant level for a few days sounds about right.

I'm not suggesting that it needs to go on a long run in order to bleed the system just whether the stat needs to be open for it to bleed properly.

[haydn callow]

Yes! the stat has to be open...but this can be done without going for a run.....as I said ..about 40 mins parked on the drive

[Aunt Trumpet]

Yes! the stat has to be open...but this can be done without going for a run.....as I said ..about 40 mins parked on the drive

Mine will sit there all day long with fans cutting in and out and the bottom hose is always cold. I changed the stat last year as I thought it wasn't working but its still the same. I even checked it with the old one and although the new one was marginally quicker there wasn't much in it. Perhaps they all have thier own strange quirks.

[dandywarhol]

Yes! the stat has to be open...but this can be done without going for a run.....as I said ..about 40 mins parked on the drive

Mine will sit there all day long with fans cutting in and out and the bottom hose is always cold. I changed the stat last year as I thought it wasn't working but its still the same. I even checked it with the old one and although the new one was marginally quicker there wasn't much in it. Perhaps they all have thier own strange quirks.

............or maybe your radiator is choked

Run it for 5/7 minutes at 2500 rpm and the bottom hose WILL get hot if all's in order........

[Aunt Trumpet]

Yes! the stat has to be open...but this can be done without going for a run.....as I said ..about 40 mins parked on the drive

Mine will sit there all day long with fans cutting in and out and the bottom hose is always cold. I changed the stat last year as I thought it wasn't working but its still the same. I even checked it with the old one and although the new one was marginally quicker there wasn't much in it. Perhaps they all have thier own strange quirks.

............or maybe your radiator is choked

Run it for 5/7 minutes at 2500 rpm and the bottom hose WILL get hot if all's in order........

I've flushed it through several times and it all seems to be in order.....my hose gets luke warm at best....which I thought was the norm to be honest...

[BongoMTBer]

Thanks for all the gen peeps. Did mine yesterday using the Haydn method and have been for a couple runs with no coolant drop so happy.

Thanks again.

[crazy uncle gray g]

I've flushed it through several times and it all seems to be in order.....my hose gets luke warm at best....which I thought was the norm to be honest...

Are you turning the heaters off again when hot and the bongo is up to running temp?
I think you'll find the stat will open much quicker then, as you are not removing any heat from the system/engine
and it will need to send the water to the rad for cooling.

[BongoMTBer]

My bottom hose didn't get hot hot hot either just a bit warm. I guess this because the ambient temperature was so low, the rad was particularly effective. I could tell when the stat opened though, as the coolant that I had spilt on the lower hose started evaporating off and the system swallowed a whole load of coolat from the funnel. I just kep't going until there were no bubbles. Also, you can feel the temperature gradient from the top of the radiator to the bottom change when the coolant is moving round.

You would know if the stat was faulty as you would have overheating issues and the needle would continue to climb when revving a 2500 rpm.

Another thanks from me for the Haydn/Allan's bleeding method, only took 20 mins and I have done 330 miles since with no coolant drop.

[haydn callow]

I've done quite a few now and as long as I fill to about 1cm over the FULL line when I've finished bleeding (to allow for the normal contraction of the coolant as it cools) I have never had to top up the next day or any other day for that matter. This tells me that all the air must be purged during the bleeding process. If you have to top up ..you either have a leak or some air must have been left in and it has worked it's way out....