coolant flushing and bleeding

[GH05T]

can some one either tell me or point me in the right direction to the thread im sure exists but i cant find, for how to properly empty, flush, refill and bleed the whole coolant system for a vn berlina with out a radiator cap. i seem to be finding miss matching information.

i have 10 ltrs of premixed coolant and radiator flush, just need to know how do to it properly.

sorry if im being dumb but im reading too many different parts of different information about bleeder valves im not sure on and coolant amounts and ways to do it and so on. thanx in advance

[dufus]

How To Flush A V6 Cooling System

[VrWagz1]

And read post #23 about bleeding. When you undo the bleeder screw i think the engine has to be hot too, so the system has some pressure to push the air out the bleeder screw and i think it sucks in coolant from the overflow bottle at the same time. thats a horrible how-to if you ask me. It needs re-doing, clarifying and simplyfying.

[GH05T]

thanx for the link, dont know why i couldnt find it,
it does seem to be a bit everywhere that write up, and the different opinions and the fact that it was written for a vs. someone definatly needs to re write it.

cheers though

[GH05T]

also the only thing he writes about filling the system back up is fill the radiator with 5lt of coolant, dosnt the system hold 10ltr? and is the best way just to fill up the block from the hose then the rad, then bleed?

is the themostate a bitch to get to in a vn? will look at mine later when i pick it up but i think its at the back??

[calais_cruzin]

Ur goin to have a bit of water left in the block. dry fill is about 10l - 12l im sure, but on a drop its not soo much

Just dump it fill it up, run til she is warm n u can feel pressure in the top hose then unscrew the bleeder hole.

What i do is jsut unscrew it then run the car, it will just spray a lil water out the hole, do it untill it stops squirting n just flows coolant out, its not hard to do

[Cheap6]

Yep, there will always be some water left in the block. The best way to get the concentration of coolant correct is to add sufficient undiluted coolant to make the concentration correct with the full system volume (found in the owner's or 'shop manuals) and then top up with water. If the system has been flushed properly, anything left in the engine will be water and a part of the final mixed coolant volume.

A series one VN V6 (no radiator cap - from the OP) doesn't have a bleed screw so not much point in looking for one. Post #20 in the 'How To' covers bleeding for them. The heater (temp. control dial) doesn't have to be on full hot though, just off the cold position. (That might make it more pleasant when getting back in the car after bleeding the system.)

On a series one, the header/surge tank on the driver's side should be the highest point in the system so any air should eventually find it's way there with the engine running.

If that is the only coolant reservoir tank in the car, fill it to about 20-25mm above the mould line in the tank.

If there is also an overflow tank on the passenger side, it is designed so that that the driver's side tank should be filled completely to the top and the passenger's side tank then acts as the overflow.

For that to work, the overcap on the driver's side tank needs to seal against the top of the driver's side tank with the 'O' ring and the hose from the overcap needs to go to the cap on the second tank. Reverting back to the single tank on the driver's side will be OK if some part of that is missing or doesn't seal.

The second passenger tank was a factory redesign on later S1 VN to ensure that the cooling system would be self bleeding. If it works, keep it if it doesn't the earlier type system will work if it is bled thoroughly. Series 2 V6 have a redesigned system with the bleed screw.

[GH05T]

Yeah I just looked, their is no bleeder valve. The thermostat is behind the engine under the throtle body. To even get to it you need to take the throttlebpdy assembly off. That's atleast 2 gasgets in itself what a ****ing dumb place to put it. I will post up a pic later but my hose connecting to it is well shagged. Any idea how much a hose pack is? Will it contain all the hoses including the one at the back cos it's separated from the hose to therad from the mettal piping running alongside the motor.

[Cheap6]

I don't know if you can buy a 'kit' of hoses as such but somewhere between $10 and $25 per hose would be ballpark. New clamps would be a good idea too. If you have a choice, the ones with the holes all the way through, as distinct from pressed into the clamp ring, are more reliable but at the cost of digging in to ends of the hose more.

The 'dumb' location of the thernostat (and the use of the metal pipe to get to it) is a legacy of the use of that engine in front wheel drive cars in the US. The position of the thermostat makes more sense for those. The conversion to RWD was obviously hurried. That's why the header/overflow tanks were rethought too.

[GH05T]

yeah the motor probly made more sence in a FWD car being sideways. all issues they obviosuly addressed in the later commos.
i thought you could get radiator hose packs for most cars? anyway

yeah, im going to replace the rear hose cos mines splitting but i cbf replacing the thermostat... even though being where it is i cant be sure it has been looked after. i was going to do it just cos its an easy job but the amount of stuff u need to pull apart just to get to it is more than i was planning.

someone needs to do a write up on how to do the cooling system on a vn cos theirs quite a bit different eh

thermo at the rear of engine
-removal of accelerator cable assembly
- removal of throttle body/ housing
-replace 2 TB gasket
-some oil/ airlines
(basically everything on top of the motor :P)

different hoses to the block

no radiator cap (i gues you need to remove different hoses when flushing??)

no bleeder valve

different reservoir tank/ no expansion tank

might be more?

can you put most other commo radiators into a vn aslong as its a v6, as in a s2 vn with radiator cap or even out of a vr/vs?

[Brin]

Dudes and dudettes,

Go down to your local library and have a look in the automotive section.

I got the Gregorys manual for my VN and a book on EFI engine management..... It was the first time i'd been to the library in two years but im def goin back now haha.

[GH05T]

ok im a little confused, if im replacing the thermo and pipes and wanna flush the system, with no rad cap or bleeder valve on the system (vn S1) ..how do i bleed the system of air?

[immortality]

ok VN s1 is about a simple as it gets. it's self bleeding.

method.
1. put flush in expansion tank (when hot) and run for 15 minutes (following instructions on bottle is best) have heater tap on hot so coolant is moving through heating radiator inside the cabin
2. drain coolant from system. i find dropping the bottom radiator hose is the easiest way. may pay to let it cool down first. putting cold water into a hot engine can cause thermal shock which isn't good.
3. put garden hose in expansion tank and let run until a good quantity has come out of the radiator hose (this flushes residual coolant out of engine)
4. put bottom radiator hose back on and fill with water untill expansion tank is full, then remove botom radiator hose again. (this helps remove more residual coolant etc)
5. re-fit bottom radiator hose (don't bother fitting hose clamp) fill with water and then run engine (leave expansion cap off) for a few minutes. heater tap on hot.. this circulates clean water through the heater system and heads

repeat steps 2, 3 and 4 again. if water runs clean then all is good. if not then do step 5 again followed by steps 2, 3 and 4.

once you are satisfied that it's all clean, re-fit bottom hose and tighten hose clamp.

fill with coolant (premix, self mix, what ever suits you really) until expansion tank is full and then run the engine until it is upto temp. monitor and add coolant as it is needed. once engine is hot and expansion tank has required coolant level. shut the engine down, let it cool down. check coolant level again and then fit expansion tank cap.

i suggest filling the fridge with a few cans of something cold and having one in between steps 1 and 2 and again after step 5.

check at supercheap for radiator hoses etc. they sell em loose so oyu don't need to get the complete set

[GH05T]

i suggest filling the fridge with a few cans of something cold and having one in between steps 1 and 2 and again after step 5.

haha so true.

thanx for the steps, but, um if its self bleeding why do i have audible air in my heater core?

EDIT:: i still have a split rear hose :P might not help haha

[VrWagz1]

Split hose is probably why. You will loose system pressure when it cools, and it wont suck water back in from the overflow bottle. Instead it will suck air in from the split in the hose.

[GH05T]

yeah exactly so i will be replacing it, obviously while i have the throttle body assembly off and im replacing the hose i will be doing the thermostat, would be stupid not to.
but i have been told that the thermostat housing will be cracked when removed, like %90 of the time you remove them and they break, especially if its been a while since doing, and by the look of the attached hose and the air/ lack of coolant reaching it at times then its not going to be in brand new shape :P

while i have hoses off and b4 i flush the system and such, are their any more hoses that i really should replace, trouble makers? their are way to many small and hidden hoses on the vn cooling system :P

.:EDIT:.
mr mechanic also recons it might be a bitch to get the thermostat housing off, depending on the condition of the Oring it might be corroded on and being where it is can take quite allot of ***in around to get off safely.
does this sound right or am i getting charged another hours labour for an easy job?

[immortality]

the thermostat can be a bitch. it is easiest to drop the TB and elbow. 3x 13mm nuts and it's off. then oyu can remove the bolt for the thermostat housing. i'd then tap it with a soft (faced) hammer to loosen it. try hitting it with lots of wd40/crc556. once you get it moving it should be fine. put a little grease on the 'O' ring when fitting thermostat housing back on

[Morton]

Yeah, an impatient mechanic is just as likely to break something as you are

Patience is the name of the game If you can't loosen it with a soft hammer, try jamming something underneath it to lever it up. Leverage and angles always work well

[GH05T]

tomorow morning and johnnywalker will tell :P

[GH05T]

WELL after looking at the thermostat housing :O my mechanic was given the task
the rear coolant pipe was shagged and corroded and it took them 2.5 hours to do which included drilling to get the thermostat housing off the block, oring design has its flores.

coolant flowing properly

with the age of the cars i dont recomend starting this job if u have somewhere to be on the day.

[VrWagz1]

Least its all done. You can get gaskets for them if you dont wanna use the O ring.