Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: robson on 25 March 2014, 17:20:45

Title: Hbv
Post by: robson on 25 March 2014, 17:20:45
Why cant I see the HBV When I look under the scuttle is it at a lower level .I am trying to feel for a coolant leak but cant find the HBV.I would like to do this without removing the scuttle if possible.Is it slightly left of centre drivers side looking from front of car.
Title: Re: Hbv
Post by: The Red Baron on 25 March 2014, 17:23:07
behind drivers side cyl head.  :y
Title: Re: Hbv
Post by: Paddy Flannery on 25 March 2014, 17:24:04
Yes, it is slightly left of centre. Looks like a wee Starship Enterprise.  :y
Title: Re: Hbv
Post by: SandBoy on 25 March 2014, 18:43:29
And an expensive part for a bit of plastic and also a hand scratcher as well!!!!! ;)
Title: Re: Hbv
Post by: omega3000 on 25 March 2014, 19:39:04
finding it is the easy bit , wait till you come to take off the hose clips  ;D Second time around gets easier  :y
Title: Re: Hbv
Post by: Darth Loo-knee on 25 March 2014, 20:30:19
Easiest way is to remove the plenum and inlet manifold. You can then get access to the hbv without removing the scuttle then struggle... just my opinion of course :y
Title: Re: Hbv
Post by: robson on 26 March 2014, 07:57:28
Thanks Darth wish you were nearer me. Does the position of the air con setting have an effect on a small coolant leak. The leak seems to be variable'
Title: Re: Hbv
Post by: robson on 26 March 2014, 08:12:03
What I mean by a leak is a loss of coolant in the bottle I am not sure where the leak is .It is not evident from looking over the hoses etc.
Title: Re: Hbv
Post by: less on 26 March 2014, 12:44:56
What I mean by a leak is a loss of coolant in the bottle I am not sure where the leak is .It is not evident from looking over the hoses etc.

Hi Robson, HBV leaks are often intermittent and may be started/stopped by turning heater temp up or down.
Title: Re: Hbv
Post by: The Red Baron on 26 March 2014, 12:59:39
What I mean by a leak is a loss of coolant in the bottle I am not sure where the leak is .It is not evident from looking over the hoses etc.

Hi Robson, HBV leaks are often intermittent and may be started/stopped by turning heater temp up or down.
on/off,  valve can leak in either position, some when open, some when closed.  :y
Title: Re: Hbv
Post by: chrisgixer on 26 March 2014, 22:05:38
Thanks Darth wish you were nearer me. Does the position of the air con setting have an effect on a small coolant leak. The leak seems to be variable'

Yes it does, test with ac in high then lo

There should be a vac pipe from the two heater matrix pipes in the bulk head to top of the hbv, of that helps. It may have fallen off its post/peg that's bolted to the back of breather box(iirc) behind cylinder 5
Title: Re: Hbv
Post by: robson on 27 March 2014, 09:01:39
Thanks Chris I think that the air con is working ok I am trying to confirm whether it is the HBV leaking before stripping out scuttle or inlet and plenum as suggested by Darth.
Title: Re: Hbv
Post by: Darth Loo-knee on 27 March 2014, 09:20:01
Ok. You say you can't see a water leak. Yet your water level is dropping.
start the car with the heater on hi. Leave it running with a torch in hand.. perhaps some paper under the car. once your convinced there is no leak,  turn the heaters down to Lo. Again cheak for the leak with tje torch okus cheak your paper. ..
I dont see any point asking you to check this that and the other yet which will only help to confuse you. :y
Title: Re: Hbv
Post by: robson on 27 March 2014, 12:09:04
Thanks Darth It now seems that with aircon off I get no loss of coolant as I have no water in the footwell,( heater matrix,) does this confirm that it is the HBV at fault.Does water flow through the heater matrix at all times or is it stopped when heater is not required. I will try your paper test where does the aircon condensate relevieve itself, will this confuse findings
Title: Re: Hbv
Post by: 05omegav6 on 27 March 2014, 13:00:28
Clue is in the name Heater Bypass Valve...

Sounds like your coolant loss is predominantly from the heater matrix not the valve if you're getting coolant in the drivers footwell :-\

You probably won't find any coolant under the car...
Title: Re: Hbv
Post by: chrisgixer on 27 March 2014, 13:03:08
Thanks Chris I think that the air con is working ok I am trying to confirm whether it is the HBV leaking before stripping out scuttle or inlet and plenum as suggested by Darth.

Yes. In order to confirm the hbv leak is leaking, you need to;
1) find it
2) see if it leaks
3) if confirmed leaking, replace it.

1) follow the vac pipe from the heater pipes in bulkhead. This leads to the hbv hopefully.
2) to test the hbv you need the engine running, which means leaving the engine parts in place, and cycling the cc from hi to lo with hand/s on the hbv each time to see/feel if it leaks.
3) once confirmed as leaking, Daz suggests removing the plenum as said. I prefer to remove the scuttle and re seal it, insuring its water tight and doesn't drip on your coil pacs. Marks Dtm suggests replacement by removing nothing but the hbv. Choice is yours.

The vac pipe from heater matrix pipes on bulk head attaches to the top of the hbv and the cc uses this via vacuum to switch the coolant flow away from the heater matrix via the hbv. This is the sole purpose of the hbv. With cc on lo the coolant flows one way through the hbv. With cc set to hi through the other coolant way in the hbv. So by switching the cc from hi to lo you are able to test both the water "ways" of the hbv.

Just to clarify ;)

Title: Re: Hbv
Post by: robson on 27 March 2014, 13:11:25
Hello Al No I dont have water in the footwell.
Title: Re: Hbv
Post by: 05omegav6 on 27 March 2014, 13:27:36
Hello Al No I dont have water in the footwell.
Ah... Ok, earlier post suggested that you might have had :-\
Title: Re: Hbv
Post by: robson on 27 March 2014, 14:18:47
Just run up to temp Air con HI Low no water under car How is it possible to get your hand under the hbv I assume that the scuttle has to come off,
Title: Re: Hbv
Post by: chrisgixer on 27 March 2014, 15:03:09
Just run up to temp Air con HI Low no water under car How is it possible to get your hand under the hbv I assume that the scuttle has to come off,
ahem.....

....FOLLOW THE VAC PIPE
Title: Re: Hbv
Post by: Bigron on 27 March 2014, 15:07:17
Please can you educate me - where is the vacuum generated for the HBV, and why?

Ron.
Title: Re: Hbv
Post by: chrisgixer on 27 March 2014, 15:18:32
That wont help you find it.

There,s plenty of info on here about it via the search button.
Title: Re: Hbv
Post by: robson on 27 March 2014, 15:23:16
Hello Chris I have found it ok but my hands are quite small and I cant get my hand under it