Thanks, Dennis!

 Eric
 Eric Wunrow Pictures

 303. 988. 8717
 VW@EricWunrow.com

On Oct 15, 2015, at 8:27 PM, Dennis Haynes <d23haynes57@HOTMAIL.COM> wrote:

> No. In a properly working system any air including air that is entrained in
> the coolant will work its way out. That is why the coolant tank is placed
> where it is, filling the lowest pressure point in the cooling system, the
> pump inlet.
>
> Dennis
>
>
> -----Original Message-----
> From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
> Eric Wunrow
> Sent: Thursday, October 15, 2015 7:53 PM
> To: vanagon@GERRY.VANAGON.COM
> Subject: Re: Missing coolant
>
> Dennis, per 'excessive over-pressurization,' could having some air in the
> cooling system specifically and solely cause the caps to fail?
>
> Our bus has never overheated - while in our possession, anyway. Even on hot
> days and climbing good mountain grades, it almost never gets much above the
> middle (straight up on the gauge). But I've been watching coolant levels
> like a hawk.
>
> Thanks,
>
> Eric
> Eric Wunrow Pictures
>
> 303. 988. 8717
> VW@EricWunrow.com
>
>
>
>
> On Oct 14, 2015, at 9:21 PM, Dennis Haynes <d23haynes57@HOTMAIL.COM> wrote:
>
>> There are a few different cap designs out there. Most rely on the
>> valve piece being sealed to the cap when it is secured on the tank so
>> the simple mouth test may not be reliable. They rely need to be tested
>> in place with a gauge set up so you can confirm the opening pressure.
>> Since the Vanagon uses the closed system approach with the recovery
>> tank once the system is completely air free, the cap has to release
>> every time engine temperature increases. On system that have an air
>> pocket under the pressure cap the system only has the cap vent during an
> overfill or overheat condition.
>>
>> While I have seen bad caps, they are usually obvious at installation.
>> Once tested good future failures are a symptom. Usually overheating or
>> excessive over pressurization is the reason for failure. Look for the
>> melted parts or damaged seals. Cracked or loose heads.
>>
>> Dennis
>>
>>
>> -----Original Message-----
>> From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On
>> Behalf Of Eric Wunrow
>> Sent: Wednesday, October 14, 2015 3:36 AM
>> To: vanagon@GERRY.VANAGON.COM
>> Subject: Re: Missing coolant
>>
>> I'm a total rookie compared to you guys, but wanted to note I've had
>> at least three expansion tank (blue) cap failures in 23,000, full-time
>> miles over 26 months on the road. I believe the failures are somewhat
>> related to how many heating/cooling cycles they're asked to do.
>>
>> I only buy the German ones, and my test is if you can both suck and
>> blow on the cap, it's toast (please keep the jokes to yourself).
>>
>> My understanding is the cap should only release pressure one direction
>> - not two.
>>
>> Eric
>> Eric Wunrow Pictures
>>
>> 303. 988. 8717
>> VW@EricWunrow.com
>>
>>
>>
>>
>> On Sep 28, 2015, at 3:27 PM, Stuart MacMillan <stuartmacm@GMAIL.COM>
> wrote:
>>
>>> Thanks Jim, the cap was replaced with an OEM cap when the water pump
>>> was
>> done 13,000 miles ago, and the overflow tank doesn't show any evidence
>> of any spillage on or under it.  I'm thinking small leaks too, but I'd
>> like to narrow it down.  The 2.1 has a lot more hoses than my 1.9!
>>>
>>>
>>>
>>> Stuart
>>>
>>>
>>>
>>> From: Jim Felder [mailto:jim.felder@gmail.com]
>>> Sent: Monday, September 28, 2015 2:21 PM
>>> To: Stuart MacMillan; vanagon@gerry.vanagon.com
>>> Subject: Re: Missing coolant
>>>
>>>
>>>
>>> Old hoses leak microscopic amounts of coolant. Ive had it spray onto
>>> the
>> engine in such small quantities that it would evaporate before you
>> could see it. Tighten hoses, replace hoses is about all you can do.
>> But you didn't mention testing the pressure cap. That can send a good
>> deal of coolant into the expansion tank, which can drip on the road
>> through the overflow and you won't know it.
>>>
>>>
>>>
>>> Jim
>>>
>>>
>>>
>>> On Mon, Sep 28, 2015 at 4:11 PM Stuart MacMillan
>>> <stuartmacm@gmail.com>
>> wrote:
>>>
>>> Just when everything seems to be sorted out, it isn't.  Son's '87 is
>>> losing over a quart of coolant every 400 miles, and I can't find any
>>> leaks.  Rear heater has been removed, and there is no odor from the
>>> front heater.  No drips anywhere-engine plumbing, heads, transmission
>>> cooler, radiator, or front heater valve.  No evidence of coolant
>>> mixing with either the transmission fluid or engine oil, and that
>>> much coolant would certainly foam oil.
>>>
>>>
>>>
>>> I'm wondering if it's burning coolant, but in my experience failed
>>> sealing rings in Vanagons lead to over pressurization of the system,
>>> and that's not happening. It also runs great. I sometimes notice a
>>> faint smell of burning coolant at the engine compartment vents, but I
>>> can't find anything dripping on the exhaust when the system is
>> pressurized.
>>>
>>>
>>>
>>> Would investing in a UV leak detection kit tell me anything?  It
>>> would seem losing this much coolant would show up somewhere.
>>>
>>>
>>>
>>> Any ideas?
>>>
>>>
>>>
>>> Stuart
>>>
>>
>